Add: README.md

.gitignore

@@ -2,3 +2,6 @@
 **.img
 **.elf
 **.cpio
+.gdb_history
+userprog/userprog
+rootfs/userprog

Makefile

@@ -1,19 +1,28 @@
 MAKE := make
+MAKEFLAGS += -j8
 
 ARCH := aarch64
 GNU := $(ARCH)-linux-gnu
 GDB := $(GNU)-gdb
 
 QEMU := qemu-system-$(ARCH)
-QEMUFLAGS += -M raspi3b -display none -serial null -serial pty
+QEMUFLAGS += -M raspi3b -display none -serial null
 
 CC := $(GNU)-gcc
 CCFLAGS += -Wall -Wextra -O0 \
+					 -mcpu=cortex-a53+nofp+nosimd \
 					 -nostdinc -nostdlib -nostartfiles -nodefaultlibs \
 					 -Wno-unused-parameter -Wno-unused-value -Wno-main -g
 LD := $(GNU)-ld
 LDFLAGS += -g -nostdlib -no-pie
 OBJCOPY := $(GNU)-objcopy
+OBJDUMP := $(GNU)-objdump
+
+MISC_DIR := misc
+QEMUFLAGS += -dtb $(MISC_DIR)/bcm2710-rpi-3-b-plus.dtb
+
+LIB_DIR := lib
+INCLUDE := -Iinclude
 
 #TARGET := kernel8
 #TARGET_DIR := ./kernel
@@ -21,37 +30,40 @@ ELF := $(TARGET).elf
 IMG := $(TARGET).img
 
 LD_SCRIPT := $(TARGET_DIR)/linker.ld
-INCLUDE += -Iinclude
-LIB_DIR := ./lib
-MISC_DIR := ./misc
-QEMUFLAGS += -dtb $(MISC_DIR)/bcm2710-rpi-3-b-plus.dtb
+INCLUDE += -I$(TARGET_DIR)/include
+TARGET_LIB_DIR := $(TARGET_DIR)/lib
 
 BOOTLOADER_DIR := ./bootloader
-ROOTFS_DIR := ./rootfs
 
+# initramfs
+ROOTFS_DIR := ./rootfs
 CPIO := initramfs.cpio
 QEMUFLAGS += -initrd $(CPIO)
 
-SRCS := $(shell find $(TARGET_DIR) -name '*.[cS]') \
-				$(shell find $(LIB_DIR) -name '*.c')
+TARGET_SRCS := $(shell find $(TARGET_DIR) -maxdepth 1 -name '*.[cS]') \
+							 $(shell find $(TARGET_LIB_DIR) -name '*.[cS]')
+TARGET_OBJS := $(TARGET_SRCS:%=%.o)
+SRCS := $(shell find $(LIB_DIR) -name '*.c')
 OBJS := $(SRCS:%=%.o)
 
-.PHONY: all build clean clean_target run kernel debug gdb
+.PHONY: all build clean clean_target run \
+        kernel bootloader userprog debug gdb objdump
 
 all: $(CPIO)
-	$(MAKE) build TARGET_DIR=./kernel TARGET=kernel8
-	$(MAKE) build TARGET_DIR=./bootloader TARGET=bootloader
+	$(MAKE) $(MAKEFLAGS) build TARGET_DIR=kernel TARGET=kernel8
+	$(MAKE) $(MAKEFLAGS) build TARGET_DIR=bootloader TARGET=bootloader
 
 build: $(IMG)
 
-$(CPIO): $(shell find $(ROOTFS_DIR))
+$(CPIO): $(shell find $(ROOTFS_DIR)) userprog
+	cp userprog/userprog $(ROOTFS_DIR)/userprog
 	cd $(ROOTFS_DIR) && find . | cpio -o -H newc > ../$@
 
 $(IMG): $(ELF)
 	$(OBJCOPY) -O binary $< $@
 
-$(ELF): $(LD_SCRIPT) $(OBJS)
-	$(LD) -o $@ -T $^ $(LDFLAGS)
+$(ELF): $(LD_SCRIPT) $(TARGET_OBJS) $(OBJS)
+	$(LD) -o $@ -T $(LD_SCRIPT) $(TARGET_OBJS) $(OBJS) $(LDFLAGS)
 
 %.S.o: %.S
 	mkdir -p $(dir $@)
@@ -62,22 +74,35 @@ $(ELF): $(LD_SCRIPT) $(OBJS)
 	$(CC) -c $< -o $@ $(INCLUDE) $(CCFLAGS)
 
 clean:
-	$(MAKE) clean_target TARGET_DIR=./kernel TARGET=kernel8
-	$(MAKE) clean_target TARGET_DIR=./bootloader TARGET=bootloader
+	-rm $(OBJS) $(CPIO) $(ROOTFS_DIR)/userprog
+	$(MAKE) $(MAKEFLAGS) -C userprog clean
+	$(MAKE) $(MAKEFLAGS) clean_target TARGET_DIR=kernel TARGET=kernel8
+	$(MAKE) $(MAKEFLAGS) clean_target TARGET_DIR=bootloader TARGET=bootloader
 
 clean_target:
-	-rm $(OBJS) $(ELF) $(IMG) $(CPIO)
+	-rm $(TARGET_OBJS) $(ELF) $(IMG)
 
 run: all $(CPIO)
-	$(QEMU) -kernel bootloader.img $(QEMUFLAGS)
+	$(QEMU) -kernel bootloader.img $(QEMUFLAGS) -serial pty
 
-kernel: all $(CPIO)
-	-killall screen
-	$(QEMU) -kernel kernel8.img $(QEMUFLAGS)
+kernel: $(CPIO)
+	$(MAKE) $(MAKEFLAGS) build TARGET_DIR=kernel TARGET=kernel8
+	$(QEMU) -kernel kernel8.img $(QEMUFLAGS) -serial stdio
 
-debug: all $(CPIO)
-	-killall screen
-	$(QEMU) -kernel kernel8.img $(QEMUFLAGS) -S -s
+bootloader: $(CPIO)
+	$(MAKE) $(MAKEFLAGS) build TARGET_DIR=bootloader TARGET=bootloader
+	$(QEMU) -kernel bootloader.img $(QEMUFLAGS) -serial stdio
+
+userprog:
+	$(MAKE) $(MAKEFLAGS) -C userprog
+
+debug: $(CPIO)
+	$(MAKE) $(MAKEFLAGS) build TARGET_DIR=kernel TARGET=kernel8
+	$(QEMU) -kernel kernel8.img $(QEMUFLAGS) -serial stdio -S -s
 
 gdb:
 	$(GDB)
+
+objdump:
+	$(MAKE) $(MAKEFLAGS) build TARGET_DIR=kernel TARGET=kernel8
+	$(OBJDUMP) -D kernel8.elf

README.md

@@ -0,0 +1 @@
+# osc2025/ytshih

bootloader/include/uart.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <stddef.h>
+
+void uart_init();
+void uart_send(uint32_t c);
+uint8_t uart_getb();
+char uart_getc();
+void uart_puts(const char *s);
+void uart_hex(uint64_t d);
+
+extern int is_uart_inited;

bootloader/lib/uart.c

@@ -0,0 +1,133 @@
+#include <uart.h>
+#include <gpio.h>
+#include <stddef.h>
+
+/* Auxilary mini UART registers */
+#define AUX_ENABLE      ((volatile unsigned int*)(MMIO_BASE + 0x00215004))
+#define AUX_MU_IO       ((volatile unsigned int*)(MMIO_BASE + 0x00215040))
+#define AUX_MU_IER      ((volatile unsigned int*)(MMIO_BASE + 0x00215044))
+#define AUX_MU_IIR      ((volatile unsigned int*)(MMIO_BASE + 0x00215048))
+#define AUX_MU_LCR      ((volatile unsigned int*)(MMIO_BASE + 0x0021504C))
+#define AUX_MU_MCR      ((volatile unsigned int*)(MMIO_BASE + 0x00215050))
+#define AUX_MU_LSR      ((volatile unsigned int*)(MMIO_BASE + 0x00215054))
+#define AUX_MU_MSR      ((volatile unsigned int*)(MMIO_BASE + 0x00215058))
+#define AUX_MU_SCRATCH  ((volatile unsigned int*)(MMIO_BASE + 0x0021505C))
+#define AUX_MU_CNTL     ((volatile unsigned int*)(MMIO_BASE + 0x00215060))
+#define AUX_MU_STAT     ((volatile unsigned int*)(MMIO_BASE + 0x00215064))
+#define AUX_MU_BAUD     ((volatile unsigned int*)(MMIO_BASE + 0x00215068))
+
+int is_uart_inited = 0;
+
+/**
+ * Set baud rate and characteristics (115200 8N1) and map to GPIO
+ */
+void uart_init()
+{
+  register unsigned int r;
+
+  /* initialize UART */
+  *AUX_ENABLE |= 1;       // enable UART1, AUX mini uart
+  *AUX_MU_CNTL = 0;
+  *AUX_MU_LCR  = 3;       // 8 bits
+  *AUX_MU_MCR  = 0;
+  *AUX_MU_IER  = 0;
+  *AUX_MU_IIR  = 0xc6;    // disable interrupts
+  *AUX_MU_BAUD = 270;    // 115200 baud
+  /* map UART1 to GPIO pins */
+  r = *GPFSEL1;
+  r &= ~((7 << 12) | (7 << 15)); // gpio14, gpio15
+  r |= (2 << 12) | (2 << 15);    // alt5
+  *GPFSEL1 = r;
+  *GPPUD = 0;            // enable pins 14 and 15
+  r = 150; while (r--) { asm volatile("nop"); }
+  *GPPUDCLK0 = (1 << 14) | (1 << 15);
+  r = 150; while (r--) { asm volatile("nop"); }
+  *GPPUDCLK0 = 0;        // flush GPIO setup
+  *AUX_MU_CNTL = 3;      // enable Tx, Rx
+
+  is_uart_inited = 1;
+}
+
+/**
+ * Send a character
+ */
+void uart_send(unsigned int c)
+{
+  /* wait until we can send */
+  do { asm volatile("nop"); } while (!(*AUX_MU_LSR & 0x20));
+  /* write the character to the buffer */
+  *AUX_MU_IO = c;
+}
+
+uint8_t uart_getb()
+{
+  uint8_t r;
+  /* wait until something is in the buffer */
+  do { asm volatile("nop"); } while (!(*AUX_MU_LSR & 0x01));
+  /* read it and return */
+  r = (uint8_t)(*AUX_MU_IO);
+
+  return r;
+}
+
+/**
+ * Receive a character
+ */
+char uart_getc()
+{
+  char r = (char)uart_getb();
+
+  /* convert carrige return to newline */
+  return r == '\r' ? '\n' : r;
+}
+
+/**
+ * Display a string
+ */
+void uart_puts(const char *s)
+{
+  while (*s) {
+    /* convert newline to carrige return + newline */
+    if(*s == '\n')
+      uart_send('\r');
+    uart_send(*s++);
+  }
+}
+
+/**
+ * Display a binary value in hexadecimal
+ */
+void uart_hex(uint64_t d)
+{
+  unsigned int n;
+  for (int c = 28; c >= 0; c -= 4) {
+    // get highest tetrad
+    n = (d >> c) & 0xF;
+    // 0-9 => '0'-'9', 10-15 => 'A'-'F'
+    n += n > 9 ? 0x37 : 0x30;
+    uart_send(n);
+  }
+}
+
+void uart_int(int d)
+{
+  unsigned int buf[11];
+  int size = 0;
+ 
+  if (d == 0) {
+    uart_send((unsigned int)'0');
+    return;
+  }
+
+  int is_neg = (d < 0);
+
+  while (d != 0) {
+    buf[size++] = '0' + d % 10;
+    d /= 10;
+  }
+
+  if (is_neg)
+    uart_send((unsigned int)'-');
+  while (size--)
+    uart_send(buf[size]);
+}

bootloader/linker.ld

@@ -1,16 +1,16 @@
 ENTRY(_start)
 MEMORY
 {
-  NEWTEXT (rx) : ORIGIN = 0x10000, LENGTH = 64K
-  NEWRO (r) : ORIGIN = 0x20000, LENGTH = 16K
-  NEWDATA (rw) : ORIGIN = 0x24000, LENGTH = 16K
-  NEWBSS (rw) : ORIGIN = 0x28000, LENGTH = 16K
+  NEWTEXT (rx) : ORIGIN = 0x10000, LENGTH = 32K
+  NEWRO (r) : ORIGIN = 0x18000, LENGTH = 8K
+  NEWDATA (rw) : ORIGIN = 0x1a000, LENGTH = 8K
+  NEWBSS (rw) : ORIGIN = 0x1c000, LENGTH = 8K
 
-  TEXT (rx) : ORIGIN = 0x80000, LENGTH = 64K
-  RO (r) : ORIGIN = 0x90000, LENGTH = 16K
-  DATA (rw) : ORIGIN = 0x94000, LENGTH = 16K
-  BSS (rw) : ORIGIN = 0x98000, LENGTH = 16K
-  RAM (rw) : ORIGIN = 0x9c000, LENGTH = 4M 
+  TEXT (rx) : ORIGIN = 0x80000, LENGTH = 32K
+  RO (r) : ORIGIN = 0x88000, LENGTH = 8K
+  DATA (rw) : ORIGIN = 0x8a000, LENGTH = 8K
+  BSS (rw) : ORIGIN = 0x8c000, LENGTH = 8K
+  RAM (rw) : ORIGIN = 0xa4000, LENGTH = 4M 
 }
 
 SECTIONS

bootloader/main.c

@@ -1,5 +1,4 @@
 #include <stddef.h>
-#include <shell.h>
 #include <uart.h>
 
 // extern uint64_t __kernel;
@@ -22,7 +21,7 @@ void main(void *dtb)
     kernel_header.buf[i] = uart_getb();
 
   uart_puts("received kernel size: ");
-  uart_int(kernel_header.size);
+  uart_hex(kernel_header.size);
   uart_puts(ENDL);
 
   uart_puts("loaded addr: ");

include/ctype.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <stddef.h>
+
+int isdigit(int);
+int isxdigit(int);
+int isupper(int);
+int isspace(int);

include/errcode.h

@@ -1,6 +1,12 @@
 #pragma once
 
-#define ERR_NO_MEM      0x00000001
-#define ERR_UNREACHABLE 0x00000002
-#define ERR_CONVERSION  0x00000003
-#define ERR_VECTOR_OOR  0x00000101
+#define NO_ERROR         0x00000000
+#define ERR_NO_MEM       0x00000001
+#define ERR_UNREACHABLE  0x00000002
+#define ERR_CONVERSION   0x00000003
+#define ERR_OUT_OF_BOUND 0x00000004
+#define ERR_INVALID_OP   0x00000005
+#define ERR_INVALID_MEM  0x00000006
+#define ERR_NOT_EXIST    0x00000007
+#define ERR_IO_FAILED    0x00000008
+#define ERR_ADMINKILL    0x00114514

include/kmalloc.h

@@ -1,7 +0,0 @@
-#pragma once
-
-#include <stddef.h>
-
-void *simple_alloc(size_t size);
-void *kmalloc(size_t size);
-void kfree(void *ptr);

include/logger.h

@@ -0,0 +1,114 @@
+#pragma once
+
+#include <stddef.h>
+#include <uart.h>
+
+#ifndef LOGLEVEL
+#define LOGLEVEL 3
+#endif
+
+#define LOGGER_BUFLEN 0x100
+
+static inline char *_do_nothing(char *dest, const char *) { return dest; }
+static inline char *_logger_string(char *dest, const char *src)
+{
+  while (*src != '\0')
+    *dest++ = *src++;
+  *dest = '\0';
+  return dest;
+}
+static inline char *_logger_hex(char *dest, uint64_t x)
+{
+  for (int n, c = 60; c >= 0; c -= 4) {
+    n = (x >> c) & 0xf;
+    n += (n > 9) ? 0x37 : 0x30;
+    *dest++ = (char)n;
+  }
+  *dest = '\0';
+  return dest;
+}
+static inline char *_logger_pointer(char *dest, void *x)
+{
+  *dest++ = '0';
+  *dest++ = 'x';
+  return _logger_hex(dest, (uint64_t)x);
+}
+
+static inline
+void _uart_puts_sync(const char *s)
+{
+  while (*s != '\0')
+    uart_putb_sync((const uint8_t *)s++, 1);
+}
+
+#define _I_HATE_C_LANG(msg) \
+logger_cur = _Generic((msg), \
+  char *      : _do_nothing, \
+  const char *: _do_nothing, \
+  default     : _logger_string \
+)(logger_cur, #msg " = "); \
+logger_cur = _Generic((msg), \
+  char *      : _logger_string, \
+  const char *: _logger_string, \
+  uint64_t    : _logger_hex, \
+  default     : _logger_pointer \
+)(logger_cur, msg)
+
+#define LOG(val) { \
+  if (logger_cur != logger_buf) \
+    logger_cur = _logger_string(logger_cur, ", "); \
+  _I_HATE_C_LANG(val); \
+}
+
+#define FLUSH(prefix) { \
+  _uart_puts_sync(prefix); \
+  _uart_puts_sync(logger_buf); \
+  _uart_puts_sync(ENDL); \
+  logger_cur = logger_buf; \
+}
+
+#define CLEAN { \
+  logger_cur = logger_buf; \
+}
+
+#if LOGLEVEL >= 0
+#define ERROR(val) { \
+  LOG(val); \
+  FLUSH("[ERROR]: "); \
+}
+#else
+#define ERROR(val) CLEAN
+#endif
+
+#if LOGLEVEL >= 1
+#define INFOR(val) { \
+  LOG(val); \
+  FLUSH("[INFOR]: "); \
+}
+#else
+#define INFOR(val) CLEAN
+#endif
+
+#if LOGLEVEL >= 2
+#define DEBUG(val) { \
+  LOG(val); \
+  FLUSH("[DEBUG]: "); \
+}
+#else // #if LOGLEVEL >= 2
+#define DEBUG(val) CLEAN
+#endif // #if LOGLEVEL >= 2
+
+// #define DEBUG_DTB(val) DEBUG(val)
+#define DEBUG_DTB(val) CLEAN
+
+#define DEBUG_EXCEP(val) DEBUG(val)
+// #define DEBUG_EXCEP(val) CLEAN
+
+// #define DEBUG_MEM(val) DEBUG(val)
+#define DEBUG_MEM(val) CLEAN
+
+// #define DEBUG_INITRD(val) DEBUG(val)
+#define DEBUG_INITRD(val) CLEAN
+
+extern char logger_buf[LOGGER_BUFLEN];
+extern char *logger_cur;

include/shell.h

@@ -1,14 +0,0 @@
-#pragma once
-
-#include <initrd.h>
-#include <stddef.h>
-
-void help(void);
-void hello(void);
-void hwinfo(void);
-void ls(file_node_t *root);
-void cat(file_node_t *root, const char *filename);
-void reboot(void);
-
-int // is continue
-shell(file_node_t *);

include/stddef.h

@@ -1,8 +1,10 @@
 #pragma once
 
-#define true 1
-#define false 0
+#define true  0x1
+#define false 0x0
+
 #define ENDL "\r\n"
+
 #define NAME_MAX 255
 #define PATH_MAX 4096
 

include/string.h

@@ -5,6 +5,7 @@
 int strcmp(const char *lhs, const char *rhs);
 char *strcpy(char *destination, const char *source);
 size_t strlen(const char *str);
+char *strtok_r(char *str, const char *delimiters, char **saveptr);
 
 void *memcpy(void *dest, const void *src, size_t count);
 void *memzero(void *start, void *end);

include/uart.h

@@ -1,25 +0,0 @@
-#pragma once
-
-#include <stddef.h>
-
-#define DEBUG(x) { \
-  uart_puts(#x " = "); \
-  uart_hex((unsigned int)(unsigned long)x); \
-  uart_puts(ENDL); \
-}
-
-#define DEBUG_s(x) { \
-  uart_puts(#x " = "); \
-  uart_puts(x); \
-  uart_puts(ENDL); \
-}
-
-void uart_init();
-void uart_send(unsigned int c);
-uint8_t uart_getb();
-char uart_getc();
-void uart_puts(const char *s);
-void uart_hex(unsigned int d);
-void uart_int(int d);
-
-extern int is_uart_init;

include/utils.h

@@ -1,31 +0,0 @@
-#pragma once
-
-#include <stddef.h>
-#include <uart.h>
-
-uint32_t msb32(uint32_t);
-
-uint32_t hton32(const uint32_t);
-uint32_t ntoh32(const uint32_t);
-
-uint64_t hton64(const uint64_t);
-uint64_t ntoh64(const uint64_t);
-
-int isdigit(int);
-int isxdigit(int);
-int isupper(int);
-int isspace(int);
-
-int32_t atoi32(const char *);
-uint32_t atoh32(const char *);
-
-void exit(int);
-
-#define MIN(x, y) (((x) < (y)) ? (x) : (y))
-#define MAX(x, y) (((x) < (y)) ? (y) : (x))
-#define ALIGN4(ptr) (void *)(((((uint64_t)(ptr) - 1) >> 2) + 1) << 2)
-#define ALIGN8(ptr) (void *)(((((uint64_t)(ptr) - 1) >> 3) + 1) << 3)
-#define BUMP(orig_type, bump_type, ptr) ( \
-  (ptr = (orig_type *)((bump_type *)ptr + 1)), \
-  ((bump_type *)ptr - 1) \
-)

kernel/Start.S

@@ -7,13 +7,16 @@ _start:
 	mrs x1, mpidr_el1
 	and x1, x1, #3
 	cbz x1, run
-	// cpu id > 0, stop
+	// cpu id > 0, fallback to wait
 wait:
 	wfe
 	b wait
 
 run: // cpu id == 0
   mov x20, x0
+
+	bl el2_to_el1
+
 	adrp x0, __stack_end
 	mov sp, x0
 
@@ -25,3 +28,11 @@ run: // cpu id == 0
 	mov x0, x20
 	bl main
 	b wait
+
+el2_to_el1:
+	mov x0, (1 << 31)
+	msr hcr_el2, x0
+	mov x0, 0x3c5
+	msr spsr_el2, x0
+	msr elr_el2, lr
+	eret

kernel/exception_table.S

@@ -0,0 +1,111 @@
+.section ".text.exception"
+
+// save general registers to stack
+.macro save_all
+	sub sp, sp, 34 * 8
+	stp x0, x1,   [sp, 16 * 0]
+	stp x2, x3,   [sp, 16 * 1]
+	stp x4, x5,   [sp, 16 * 2]
+	stp x6, x7,   [sp, 16 * 3]
+	stp x8, x9,   [sp, 16 * 4]
+	stp x10, x11, [sp, 16 * 5]
+	stp x12, x13, [sp, 16 * 6]
+	stp x14, x15, [sp, 16 * 7]
+	stp x16, x17, [sp, 16 * 8]
+	stp x18, x19, [sp, 16 * 9]
+	stp x20, x21, [sp, 16 * 10]
+	stp x22, x23, [sp, 16 * 11]
+	stp x24, x25, [sp, 16 * 12]
+	stp x26, x27, [sp, 16 * 13]
+	stp x28, x29, [sp, 16 * 14]
+
+  mrs x0, spsr_el1
+  mrs x1, elr_el1
+  mrs x2, esr_el1
+  stp x0, x1,   [sp, 16 * 15]
+  stp x2, lr,   [sp, 16 * 16]
+.endm
+
+// load general registers from stack
+.macro load_all
+  ldp x0, x1,   [sp, 16 * 15]
+  ldp x2, lr,   [sp, 16 * 16]
+  msr spsr_el1, x0
+  msr elr_el1,  x1
+  msr esr_el1,  x2
+
+	ldp x0, x1,   [sp, 16 * 0]
+	ldp x2, x3,   [sp, 16 * 1]
+	ldp x4, x5,   [sp, 16 * 2]
+	ldp x6, x7,   [sp, 16 * 3]
+	ldp x8, x9,   [sp, 16 * 4]
+	ldp x10, x11, [sp, 16 * 5]
+	ldp x12, x13, [sp, 16 * 6]
+	ldp x14, x15, [sp, 16 * 7]
+	ldp x16, x17, [sp, 16 * 8]
+	ldp x18, x19, [sp, 16 * 9]
+	ldp x20, x21, [sp, 16 * 10]
+	ldp x22, x23, [sp, 16 * 11]
+	ldp x24, x25, [sp, 16 * 12]
+	ldp x26, x27, [sp, 16 * 13]
+	ldp x28, x29, [sp, 16 * 14]
+
+	add sp, sp, 34 * 8
+.endm
+
+_null_handler:
+	save_all
+	bl not_implemented_handler
+	load_all
+	eret
+
+_synchronous_handler:
+  save_all
+  bl synchronous_handler
+  load_all
+  eret
+
+_irq_handler:
+  save_all
+  bl irq_handler
+  load_all
+  eret
+
+.align 11
+.global exception_vector_table
+exception_vector_table:
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+
+	b _synchronous_handler
+	.align 7
+	b _irq_handler
+	.align 7
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+
+	b _synchronous_handler
+	.align 7
+	b _irq_handler
+	.align 7
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7
+	b _null_handler
+	.align 7

kernel/include/dtb.h

@@ -40,13 +40,16 @@ typedef struct {
 
 #define FDT_PATH_BUFFER_LEN 0x10
 
-typedef void (*fdt_callback_func_t)(const vector_t *props);
+typedef void (*fdt_callback_func_t)(const vector_t *);
 typedef struct {
   const char *name;
   const fdt_callback_func_t func;
 } fdt_callback_t;
 
-void fdt_callback(const char *path, const vector_t *cbs, const vector_t *props);
-void fdt_traverse(const vector_t *cbs);
+void fdt_traverse(const vector_t *struct_cbs);
 
-extern void *dtb_addr;
+extern void *dtb_start;
+extern void *dtb_end;
+extern void *dtb_memory_start;
+extern void *dtb_memory_end;
+extern vector_t *dtb_reserved_entries;

kernel/include/exception.h

@@ -0,0 +1,5 @@
+#pragma once
+
+void init_exception(void);
+void not_implemented_handler(void);
+void synchronous_handler(void);

kernel/include/exec.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void user_exec(void *text, void *sp);

kernel/include/interrupt.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef void (*interrupt_callback_func_t)(uint64_t);
+
+typedef struct interrupt {
+  struct interrupt *_l, *_r;
+  uint32_t _d;
+
+  uint64_t priority;
+  interrupt_callback_func_t func;
+  uint64_t param;
+} interrupt_t;
+
+void add_interrupt_task(uint64_t priority,
+                        interrupt_callback_func_t func,
+                        uint64_t param);
+
+void init_interrupt(void);
+void irq_handler(void);
+
+void wfe(void);
+
+extern interrupt_t *global_interrupt_pool;

kernel/include/kmalloc.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <stddef.h>
+
+#define KMALLOC_MAX_ALLOCATOR_SIZE 256
+
+typedef struct kmalloc_header {
+  size_t unit;
+  size_t left;
+  void *begin;
+  struct kmalloc_header *page_prev, *page_next;
+}__attribute__((packed)) kmalloc_header_t;
+
+typedef struct {
+  size_t left;
+  kmalloc_header_t *page_begin;
+} kmalloc_allocator_t;
+
+void init_mman_kmalloc();
+void *simple_alloc(size_t size);
+void *mman_alloc(size_t size);
+void mman_free(void *ptr);
+
+extern void *(*kmalloc)(size_t size);
+extern void (*kfree)(void *ptr);
+
+extern kmalloc_allocator_t mman_kmalloc_pool[KMALLOC_MAX_ALLOCATOR_SIZE + 1];

kernel/include/mman.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <stddef.h>
+#include <dtb.h>
+
+#define MMAN_NO_PAGE 0xffffffffffffffff
+#define PAGE_SIZE (1 << 12)
+
+// PAGE_FREE      => available
+// PAGE_ALLOCATED => this range is allocated explicitly
+// PAGE_DIVIDED   => this range is divided into smaller range
+// PAGE_RESERVED  => this range is reserved explicitly
+typedef enum :uint8_t {
+  PAGE_FREE      = 0,
+  PAGE_ALLOCATED = 1,
+  PAGE_DIVIDED   = 2,
+  PAGE_RESERVED  = 3,
+} page_state_t;
+
+typedef struct {
+  page_state_t state;
+  uint64_t maxsz;
+} page_header_t;
+
+void mman_init();
+
+void *allocate_page(size_t page_cnt);
+void free_page(void *ptr);
+void reserve_page(void *begin, void *end);
+
+void mman_fdt_memory_cb_func(const vector_t *props);
+
+extern fdt_callback_t mman_dtb_memory_cb;
+extern void *mman_memory_start;
+extern void *mman_memory_end;
+extern size_t mman_page_cnt;
+extern page_header_t *mman_frame_array;

kernel/include/queue.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef struct queue_node {
+  struct queue_node *prev, *next;
+  uint64_t value;
+} queue_node_t;
+
+typedef struct queue {
+  size_t size;
+
+  queue_node_t *begin, *end;
+} queue_t;
+
+queue_t *make_queue();
+
+uint64_t queue_back(const queue_t *queue);
+uint64_t queue_front(const queue_t *queue);
+
+void queue_push_back(queue_t *queue, uint64_t val);
+void queue_push_front(queue_t *queue, uint64_t val);
+
+#define QUEUE_BACK(type, queue) ((type *)queue_back(queue))
+#define QUEUE_FRONT(type, queue) ((type *)queue_front(queue))
+#define QUEUE_PUSH_BACK(queue, val) \
+  queue_push_back(queue, (uint64_t)val)
+#define QUEUE_PUSH_FRONT(queue, val) \
+  queue_push_front(queue, (uint64_t)val)

kernel/include/ringbuffer.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef struct {
+  size_t size;
+  size_t cap;
+  uint8_t *data;
+  uint8_t *read, *write;
+} ringbuffer_t;
+
+ringbuffer_t *make_ringbuffer(size_t size);
+int ringbuffer_push(ringbuffer_t *buf, uint8_t val);
+uint8_t ringbuffer_bump(ringbuffer_t *buf);

kernel/include/shell.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stddef.h>
+#include <initrd.h>
+
+int // is continue
+shell(file_node_t *);

kernel/include/timer.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef void (*task_callback_func_t)(uint64_t);
+
+typedef struct {
+  uint64_t firing_tick;
+  uint64_t interval;
+  uint64_t repeat;
+
+  task_callback_func_t func;
+  uint64_t param;
+} task_t;
+
+typedef struct timer {
+  struct timer *_l, *_r;
+  uint32_t _d;
+
+  task_t data;
+} timer_t;
+
+void add_task(task_t task);
+
+void timer_irq_handler(void);
+
+extern timer_t *global_timer;

kernel/include/uart.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <stddef.h>
+#include <ringbuffer.h>
+
+#define UART_BUFLEN 0x800
+
+void uart_init(void);
+char uart_getc(void);
+void uart_puts(const char *s);
+void uart_hex(uint64_t d);
+
+void uart_irq_handler(void);
+
+size_t uart_putb_sync(const uint8_t *bytes, size_t len);
+size_t uart_getb_sync(uint8_t *bytes, size_t len);
+
+size_t uart_putb_async(const uint8_t *bytes, size_t len);
+size_t uart_getb_async(uint8_t *bytes, size_t len);
+
+extern size_t (*uart_putb)(const uint8_t *bytes, size_t len);
+extern size_t (*uart_getb)(uint8_t *bytes, size_t len);
+extern int is_uart_inited;
+
+extern ringbuffer_t *uart_readbuf;

kernel/include/utils.h

@@ -0,0 +1,78 @@
+#pragma once
+
+#include <stddef.h>
+#include <uart.h>
+
+uint32_t msb32(uint32_t);
+uint64_t msb64(uint64_t);
+
+uint32_t hton32(const uint32_t);
+uint32_t ntoh32(const uint32_t);
+
+uint64_t hton64(const uint64_t);
+uint64_t ntoh64(const uint64_t);
+
+int isdigit(int);
+int isxdigit(int);
+int isupper(int);
+int isspace(int);
+
+int32_t atoi32(const char *);
+uint32_t atoh32(const char *);
+
+void exit(int);
+
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+#define MAX(x, y) (((x) < (y)) ? (y) : (x))
+
+#define ALIGN(ptr, cnt) (void *)((( \
+  ((uint64_t)(ptr) - 1) >> (cnt)) + 1) << (cnt))
+
+#define ALIGN4(ptr)  ALIGN(ptr, 2)
+#define ALIGN8(ptr)  ALIGN(ptr, 3)
+#define ALIGN4K(ptr) ALIGN(ptr, 12)
+
+#define BUMP(orig_type, bump_type, ptr) ( \
+  (ptr = (orig_type*)((bump_type*)ptr + 1)), \
+  ((bump_type*)ptr - 1) \
+)
+
+#define R_SYSREG(ret, reg) \
+  asm volatile( \
+    "mrs %[a], " #reg \
+    : [a] "=r" (ret) \
+  )
+
+#define W_SYSREG(reg, val) \
+  asm volatile( \
+    "mov x0, %[a]" ENDL \
+    "msr " #reg ", x0" ENDL \
+    :: [a] "r" (val) \
+    : "x0" \
+  )
+
+#define W_SYSREG_IMM(reg, val) \
+  asm volatile( \
+    "msr " #reg ", %[a]" \
+    :: [a] "i" (val) \
+  )
+
+#define R_REG(ret, reg) \
+  asm volatile( \
+    "mov %[a], " #reg \
+    : [a] "=r" (ret) \
+  )
+
+#define W_REG(reg, val) \
+  asm volatile( \
+    "mov " #reg ", %[a]" \
+    :: [a] "r" (val) \
+  )
+
+#define MMIO_W_HELPER(name, reg, mask, offset) \
+  static inline void name(uint64_t state) \
+  { *reg = (*reg & ~((mask) << (offset))) | ((state & (mask)) << (offset)); }
+
+#define MMIO_R_HELPER(name, reg, mask, offset) \
+  static inline uint64_t name(void) \
+  { return (*reg >> (offset)) & (mask); }

kernel/include/vector.h

@@ -12,7 +12,7 @@ typedef struct {
 vector_t *make_vector(size_t size);
 
 uint64_t vec_at(const vector_t *vec, size_t idx);
-vector_t *vec_push(vector_t *vec, uint64_t val);
+void vec_push(vector_t *vec, uint64_t val);
 
 #define VEC_AT(type, vec, idx) ((type *)vec_at((vec), (idx)))
-#define VEC_PUSH(vec, val) vec = vec_push(vec, (uint64_t)val)
+#define VEC_PUSH(vec, val) vec_push(vec, (uint64_t)val)

kernel/lib/dtb.c

@@ -1,24 +1,43 @@
+#include <logger.h>
 #include <errcode.h>
 #include <dtb.h>
 #include <utils.h>
 #include <string.h>
-#include <uart.h>
 #include <kmalloc.h>
 #include <vector.h>
 
-void *dtb_addr;
+void *dtb_start;
+void *dtb_end;
+void *dtb_memory_start;
+void *dtb_memory_end;
+vector_t *dtb_reserved_entries;
 
-void fdt_callback(const char *path, const vector_t *cbs, const vector_t *props)
+fdt_reserve_entry_t *fdt_memory_cur;
+uint32_t *fdt_struct_cur;
+
+static inline
+void _fdt_struct_callback(const char *path, const vector_t *cbs, const vector_t *props)
 {
   for (int i = 0; i < (int)cbs->size; ++i)
     if (!strcmp(path, VEC_AT(fdt_callback_t, cbs, i)->name))
       VEC_AT(fdt_callback_t, cbs, i)->func(props);
 }
 
-uint32_t *fdt_struct_cur;
+static inline
+void _memory_traverse()
+{
+  dtb_reserved_entries = make_vector(0);
+  while (fdt_memory_cur->address != 0 || fdt_memory_cur->size != 0) {
+    DEBUG_DTB(ntoh64(fdt_memory_cur->address));
+    DEBUG_DTB(ntoh64(fdt_memory_cur->size));
+
+    VEC_PUSH(dtb_reserved_entries, fdt_memory_cur++);
+  }
+}
 
 #define nextnode(ptr) (void *)((((uint64_t)(ptr) >> 2) + 1) << 2)
-void traverse(const char *path, const vector_t *cbs)
+static inline
+void _struct_traverse(const char *path, const vector_t *cbs)
 {
   vector_t *props = make_vector(0);
 
@@ -31,7 +50,7 @@ void traverse(const char *path, const vector_t *cbs)
 
     switch (ntoh32(*fdt_struct_cur)) {
     case FDT_BEGIN_NODE:
-      BUMP(uint32_t, uint32_t, fdt_struct_cur);
+      ++fdt_struct_cur;
       fdt_node_path = (void *)fdt_struct_cur;
       do {
         BUMP(uint32_t, char, fdt_struct_cur);
@@ -39,19 +58,19 @@ void traverse(const char *path, const vector_t *cbs)
       BUMP(uint32_t, char, fdt_struct_cur); // '\0'
 
       fdt_struct_cur = ALIGN4(fdt_struct_cur);
-      traverse(fdt_node_path, cbs);
+      _struct_traverse(fdt_node_path, cbs);
       break;
     case FDT_END_NODE:
       fdt_struct_cur = nextnode(fdt_struct_cur);
-      goto traverse_callback;
+      goto traverse_struct_callback;
     case FDT_PROP:
-      BUMP(uint32_t, uint32_t, fdt_struct_cur);
+      ++fdt_struct_cur;
       prop_header = BUMP(uint32_t, fdt_prop_header_t, fdt_struct_cur);
 
       prop = kmalloc(sizeof(fdt_prop_t));
       prop->len = ntoh32(prop_header->len);
-      prop->name = dtb_addr + 
-                   ntoh32(((fdt_header_t *)dtb_addr)->off_dt_strings) +
+      prop->name = dtb_start + 
+                   ntoh32(((fdt_header_t *)dtb_start)->off_dt_strings) +
                    ntoh32(prop_header->nameoff);
       prop->value = (void *)fdt_struct_cur;
       VEC_PUSH(props, prop);
@@ -69,13 +88,23 @@ void traverse(const char *path, const vector_t *cbs)
       exit(ERR_UNREACHABLE);
     }
   }
-traverse_callback:
-  fdt_callback(path, cbs, props);
+traverse_struct_callback:
+  _fdt_struct_callback(path, cbs, props);
 }
 
-void fdt_traverse(const vector_t *cbs)
+void fdt_traverse(const vector_t *struct_cbs)
 {
-  fdt_struct_cur = dtb_addr + ntoh32(((fdt_header_t *)dtb_addr)->off_dt_struct);
+  fdt_memory_cur = dtb_start + 
+    ntoh32(((fdt_header_t *)dtb_start)->off_mem_rsvmap);
+  fdt_struct_cur = dtb_start + 
+    ntoh32(((fdt_header_t *)dtb_start)->off_dt_struct);
+  dtb_end = dtb_start +
+    ntoh32(((fdt_header_t *)dtb_start)->totalsize);
 
-  traverse("", cbs);
+  DEBUG_DTB(fdt_memory_cur);
+  DEBUG_DTB(fdt_struct_cur);
+  _memory_traverse();
+  DEBUG_DTB("memory traverse done");
+  _struct_traverse("", struct_cbs);
+  DEBUG_DTB("struct traverse done");
 }

kernel/lib/exception.c

@@ -0,0 +1,42 @@
+#include <exception.h>
+#include <errcode.h>
+#include <stddef.h>
+#include <logger.h>
+#include <utils.h>
+
+void init_exception()
+{
+  asm volatile(
+    "adr x0, exception_vector_table" ENDL
+    "msr vbar_el1, x0" ENDL
+    ::: "x0"
+  );
+}
+
+void not_implemented_handler()
+{
+  DEBUG_EXCEP("not implemented caught");
+}
+
+void synchronous_handler()
+{
+  static int poop = 0;
+  if (poop++ > 5)
+    exit(ERR_ADMINKILL);
+  DEBUG_EXCEP("synchronous caught");
+  uint64_t x0 = 0x0;
+  R_REG(x0, x0);
+  LOG(x0);
+  
+  uint64_t spsr_el1 = 0x0;
+  R_SYSREG(spsr_el1, spsr_el1);
+  LOG(spsr_el1);
+
+  uint64_t elr_el1 = 0x0;
+  R_SYSREG(elr_el1, elr_el1);
+  LOG(elr_el1);
+
+  uint64_t esr_el1 = 0x0;
+  R_SYSREG(esr_el1, esr_el1);
+  DEBUG_EXCEP(esr_el1);
+}

kernel/lib/exec.c

@@ -0,0 +1,16 @@
+#include <exec.h>
+#include <utils.h>
+
+void user_exec(void *text, void *sp)
+{
+  // enable core timer
+  uint64_t cntkctl_el1 = 0x0;
+  R_SYSREG(cntkctl_el1, cntkctl_el1);
+  W_SYSREG(cntkctl_el1, cntkctl_el1 | 1);
+  W_SYSREG(cntp_ctl_el0, 1);
+  
+  W_SYSREG(spsr_el1, 0);
+  W_SYSREG(elr_el1, text);
+  W_SYSREG(sp_el0, sp);
+  asm volatile("eret");
+}

kernel/lib/initrd.c

@@ -29,14 +29,14 @@ void initrd_fdt_callback(const vector_t *props)
   }
 }
 
-void _init_node(file_node_t *node) {
+static inline void _init_node(file_node_t *node) {
   node->l = nullnode;
   node->r = nullnode;
   node->rand = random();
   node->node_size = 1;
 }
 
-void _pull_from(file_node_t *to, file_node_t *from)
+static inline void _pull_from(file_node_t *to, file_node_t *from)
 {
   if (!from)
     return;
@@ -44,14 +44,14 @@ void _pull_from(file_node_t *to, file_node_t *from)
   to->node_size += from->node_size;
 }
 
-void _pull(file_node_t *node)
+static inline void _pull(file_node_t *node)
 {
   node->node_size = 1;
   _pull_from(node, node->l);
   _pull_from(node, node->r);
 }
 
-file_node_t *_merge(file_node_t *a, file_node_t *b)
+static inline file_node_t *_merge(file_node_t *a, file_node_t *b)
 {
   if (!a || !b)
     return a ?: b;
@@ -66,7 +66,8 @@ file_node_t *_merge(file_node_t *a, file_node_t *b)
   return b;
 }
 
-void _split(file_node_t *rt, const char *s, file_node_t **a, file_node_t **b)
+static inline void _split(file_node_t *rt, const char *s,
+                          file_node_t **a, file_node_t **b)
 {
   if (!rt) {
     *a = *b = nullnode;
@@ -96,7 +97,7 @@ file_node_t *initrd_init(void)
 
   file_node_t *root = nullnode, *ltr, *rtr;
   for (;;) {
-    header = BUMP(cpio_newc_header_t, cpio_newc_header_t, initrd_cur);
+    header = initrd_cur++;
 
     filename = (void *)initrd_cur;
     if (!strcmp(filename, "TRAILER!!!"))
@@ -124,8 +125,6 @@ file_node_t *initrd_init(void)
     newnode->filename = filename;
     newnode->filecontent = filecontent;
 
-    DEBUG_s(filename);
-
     _split(root, filename, &ltr, &rtr);
     root = _merge(ltr, _merge(newnode, rtr));
   }
@@ -133,7 +132,7 @@ file_node_t *initrd_init(void)
   return root;
 }
 
-file_node_t *_node_bs(file_node_t *cur, const char *s)
+static inline file_node_t *_node_bs(file_node_t *cur, const char *s)
 {
   if (!cur) 
     return nullnode;

kernel/lib/interrupt.c

@@ -0,0 +1,118 @@
+#include <interrupt.h>
+#include <kmalloc.h>
+#include <uart.h>
+#include <timer.h>
+#include <utils.h>
+#include <logger.h>
+#include <errcode.h>
+
+#define CORE0_TIMER_IRQ_CTRL ((volatile uint32_t *)0x40000040)
+#define CORE0_IRQ_SOURCE     ((volatile uint32_t *)0x40000060)
+
+interrupt_t *global_interrupt_pool = (interrupt_t *)0x0;
+
+static inline
+void _enable_interrupt(void)
+{ W_SYSREG_IMM(DAIFClr, 0xf); }
+
+static inline
+void _disable_interrupt(void)
+{ W_SYSREG_IMM(DAIFSet, 0xf); }
+
+MMIO_W_HELPER(_enable_timer_irq, CORE0_TIMER_IRQ_CTRL, 0x1, 1);
+
+MMIO_R_HELPER(_irq_source_timer, CORE0_IRQ_SOURCE, 0x1, 1);
+MMIO_R_HELPER(_irq_source_uart,  CORE0_IRQ_SOURCE, 0x1, 8);
+
+static inline
+uint32_t _d(interrupt_t *interrupt)
+{ return interrupt ? interrupt->_d : 0; }
+
+static inline
+void _swap(interrupt_t **a, interrupt_t **b)
+{
+  interrupt_t *tmp = *a;
+  *a = *b, *b = tmp;
+}
+
+static inline
+interrupt_t *_merge(interrupt_t *a, interrupt_t *b)
+{
+  if (!a || !b)
+    return a ?: b;
+
+  if (a->priority < b->priority)
+    _swap(&a, &b);
+  a->_r = _merge(a->_r, b);
+
+  if (_d(a->_l) < _d(a->_r))
+    _swap(&a->_l, &a->_r);
+
+  a->_d = _d(a->_r) + 1;
+  return a;
+}
+
+static inline
+interrupt_t *_pop(interrupt_t *interrupt)
+{
+  if (!interrupt || (!interrupt->_l && !interrupt->_r))
+    return (interrupt_t *)0x0;
+  return _merge(interrupt->_l, interrupt->_r);
+}
+
+void add_interrupt_task(uint64_t priority,
+                        interrupt_callback_func_t func,
+                        uint64_t param)
+{
+  // DEBUG_EXCEP("add interrupt");
+  interrupt_t *newint = kmalloc(sizeof(interrupt_t));
+  *newint = (interrupt_t){
+    ._l = (interrupt_t *)0x0,
+    ._r = (interrupt_t *)0x0,
+    ._d = 0,
+
+    .priority = priority,
+    .func = func,
+    .param = param
+  };
+
+  global_interrupt_pool = _merge(global_interrupt_pool, newint);
+}
+
+void init_interrupt(void)
+{
+  uint64_t cntfrq_el0;
+  W_SYSREG(cntp_ctl_el0, 1);
+  R_SYSREG(cntfrq_el0, cntfrq_el0);
+  W_SYSREG(cntp_tval_el0, cntfrq_el0);
+
+  _enable_timer_irq(true);
+  _enable_interrupt();
+}
+
+void irq_handler(void)
+{
+  // uint64_t core0_irq_source = *CORE0_IRQ_SOURCE;
+  // DEBUG_EXCEP(core0_irq_source);
+
+  if (_irq_source_timer())
+    timer_irq_handler();
+
+  if (_irq_source_uart())
+    uart_irq_handler();
+}
+
+void wfe(void)
+{
+  if (!global_interrupt_pool) {
+    // asm volatile("wfe");
+    asm volatile("nop");
+    return;
+  }
+
+  interrupt_t *interrupt = global_interrupt_pool;
+  global_interrupt_pool = _merge(global_interrupt_pool->_l,
+                                 global_interrupt_pool->_r);
+
+  interrupt->func(interrupt->param);
+}

kernel/lib/kmalloc.c

@@ -0,0 +1,114 @@
+#include <uart.h>
+#include <errcode.h>
+#include <utils.h>
+#include <kmalloc.h>
+#include <stddef.h>
+#include <mman.h>
+
+extern uint64_t __heap_start;
+extern uint64_t __heap_end;
+
+void *(*kmalloc)(size_t size) = simple_alloc;
+void (*kfree)(void *ptr) = (void (*)(void *))0x0;
+
+kmalloc_allocator_t mman_kmalloc_pool[KMALLOC_MAX_ALLOCATOR_SIZE + 1];
+
+void *_heap_top = (void *)0x0;
+
+void init_mman_kmalloc()
+{
+  for (int i = 1; i <= KMALLOC_MAX_ALLOCATOR_SIZE; ++i)
+    mman_kmalloc_pool[i] = (kmalloc_allocator_t){
+      .left = 0,
+      .page_begin = (kmalloc_header_t *)0x0,
+    };
+
+  kmalloc = mman_alloc;
+  kfree   = mman_free;
+}
+
+// simple 8-byte aligned linear allocation
+void *simple_alloc(size_t size)
+{
+  if (!_heap_top) {
+    _heap_top = (void *)&__heap_start;
+  }
+
+  size = (size_t)ALIGN8(size);
+  
+  if ((uint64_t)_heap_top + size >= (uint64_t)&__heap_end)
+    exit(ERR_NO_MEM);
+
+  void *ret = _heap_top;
+  _heap_top = (void *)((uint64_t)_heap_top + size);
+
+  return ret;
+}
+
+#define PAGE_HEADER(ptr) ((kmalloc_header_t *)(((uint64_t)(ptr) >> 12) << 12))
+
+void *mman_alloc(size_t unit)
+{
+  unit = (size_t)ALIGN8(unit);
+  if (unit > (KMALLOC_MAX_ALLOCATOR_SIZE << 3))
+    return allocate_page(((unit - 1) >> 12) + 1);
+
+  kmalloc_allocator_t *pool = &mman_kmalloc_pool[unit >> 3];
+  if (!pool->left) {
+    void *page = allocate_page(1), *ptr = page + sizeof(kmalloc_header_t);
+    *(kmalloc_header_t *)page = (kmalloc_header_t){
+      .unit = unit,
+      .left = (PAGE_SIZE - sizeof(kmalloc_header_t)) / unit,
+      .begin = page + sizeof(kmalloc_header_t),
+      .page_prev = (kmalloc_header_t *)0x0,
+      .page_next = (kmalloc_header_t *)0x0,
+    };
+    *pool = (kmalloc_allocator_t){
+      .left = ((kmalloc_header_t *)page)->left,
+      .page_begin = (kmalloc_header_t *)page,
+    };
+
+    for (; ptr + unit <= page + PAGE_SIZE; ptr += unit)
+      *(void **)ptr = ptr + unit;
+  }
+
+  void *ret = pool->page_begin->begin;
+  pool->page_begin->begin = *(void **)pool->page_begin->begin;
+  
+  --pool->left;
+  --pool->page_begin->left;
+  if (!pool->page_begin->left)
+    pool->page_begin = *(void **)pool->page_begin->page_next;
+
+  return ret;
+}
+
+void mman_free(void *ptr)
+{
+  if (ptr == ALIGN4K(ptr)) {
+    free_page(ptr);
+    return;
+  }
+
+  size_t unit = PAGE_HEADER(ptr)->unit;
+  kmalloc_allocator_t *pool = &mman_kmalloc_pool[unit >> 3];
+  if (!PAGE_HEADER(ptr)->left) {
+    PAGE_HEADER(ptr)->page_next = pool->page_begin;
+    pool->page_begin->page_prev = PAGE_HEADER(ptr);
+    pool->page_begin = PAGE_HEADER(ptr);
+  }
+
+  *(void **)ptr = pool->page_begin->begin;
+  pool->page_begin->begin = ptr;
+  
+  ++pool->left;
+  ++PAGE_HEADER(ptr)->left;
+  size_t cap = (PAGE_SIZE - sizeof(kmalloc_allocator_t)) / unit;
+  if (PAGE_HEADER(ptr)->left == cap && pool->left >= 2 * cap) {
+    if (PAGE_HEADER(ptr)->page_prev)
+      PAGE_HEADER(ptr)->page_prev->page_next = PAGE_HEADER(ptr)->page_next;
+    if (PAGE_HEADER(ptr)->page_next)
+      PAGE_HEADER(ptr)->page_next->page_prev = PAGE_HEADER(ptr)->page_prev;
+    free_page(PAGE_HEADER(ptr));
+  }
+}

kernel/lib/mman.c

@@ -0,0 +1,248 @@
+#include <mman.h>
+#include <logger.h>
+#include <errcode.h>
+#include <string.h>
+#include <utils.h>
+#include <kmalloc.h>
+#include <dtb.h>
+#include <initrd.h>
+
+extern uint64_t __kernel_start;
+extern uint64_t __kernel_end;
+extern uint64_t __heap_start;
+extern uint64_t __stack_end;
+
+fdt_callback_t mman_dtb_memory_cb = {
+  .name = "memory@0",
+  .func = mman_fdt_memory_cb_func,
+};
+
+void *mman_memory_start = 0x0;
+void *mman_memory_end   = 0x0;
+size_t mman_page_cnt = 0;
+page_header_t *mman_frame_array = 0x0;
+
+void mman_fdt_memory_cb_func(const vector_t *props)
+{
+  for (int i = 0; i < (int)props->size; ++i) {
+    if (!strcmp(VEC_AT(fdt_prop_t, props, i)->name, "reg")) {
+      mman_memory_start = (void *)(uint64_t)ntoh32(
+        *((uint32_t *)VEC_AT(fdt_prop_t, props, i)->value));
+      mman_memory_end = (void *)(uint64_t)ntoh32(
+        *((uint32_t *)VEC_AT(fdt_prop_t, props, i)->value + 1));
+    }
+  }
+}
+
+// This is an array-like binary tree structure, where LCH (left-child) will 
+// always be the largest 2^k size block while RCH not empty.
+#define CUR (&mman_frame_array[idx])
+#define LIDX (((idx + 1) << 1) - 1)
+#define LCH (&mman_frame_array[LIDX])
+#define RIDX (((idx + 1) << 1 | 1) - 1)
+#define RCH (&mman_frame_array[RIDX])
+
+static inline
+void _pull(int idx, size_t sz)
+{
+  if (LCH->state == PAGE_FREE && RCH->state == PAGE_FREE) {
+    if (CUR->state != PAGE_FREE) {
+      LOG("node merged");
+      DEBUG_MEM((uint64_t)idx);
+    }
+    CUR->state = PAGE_FREE;
+  }
+  if (LCH->state != PAGE_FREE || RCH->state != PAGE_FREE)
+    CUR->state = PAGE_DIVIDED;
+  switch (CUR->state) {
+  case PAGE_FREE:
+    CUR->maxsz = sz;
+    break;
+  case PAGE_DIVIDED:
+    CUR->maxsz = MAX(LCH->maxsz, RCH->maxsz);
+    break;
+  case PAGE_ALLOCATED:
+  case PAGE_RESERVED:
+    CUR->maxsz = 0;
+    break;
+  default:
+    exit(ERR_UNREACHABLE);
+  }
+}
+
+void mman_init()
+{
+  mman_memory_start = ALIGN4K(mman_memory_start);
+  mman_memory_end   = ALIGN4K(mman_memory_end);
+
+  // 4KB per page
+  mman_page_cnt = (mman_memory_end - mman_memory_start) >> 12;
+  mman_frame_array = simple_alloc((mman_page_cnt << 1) * sizeof(page_header_t));
+
+  LOG(mman_memory_start);
+  LOG(mman_memory_end);
+  DEBUG_MEM((uint64_t)mman_page_cnt);
+
+  mman_frame_array[0] = (page_header_t){
+    .state = PAGE_FREE,
+    .maxsz = msb64(mman_page_cnt),
+  };
+
+  fdt_reserve_entry_t *entry = 0x0;
+  for (int i = 0; i < (int)dtb_reserved_entries->size; ++i) {
+    entry = VEC_AT(fdt_reserve_entry_t, dtb_reserved_entries, i);
+    LOG(ntoh64(entry->address));
+    DEBUG_MEM(ntoh64(entry->address) + ntoh64(entry->size));
+    reserve_page((void *)ntoh64(entry->address),
+      (void *)ntoh64(entry->address) + ntoh64(entry->size));
+  }
+
+  reserve_page(&__kernel_start, &__kernel_end);
+  reserve_page(&__heap_start, &__stack_end);
+  reserve_page(dtb_start, dtb_end);
+  reserve_page(initrd_start, initrd_end);
+
+  init_mman_kmalloc();
+}
+
+static inline
+uint64_t _allocate_page(size_t req, int idx, uint64_t l, uint64_t r)
+{
+  uint64_t sz = r - l;
+  if (req > sz || req > CUR->maxsz) {
+    return MMAN_NO_PAGE;
+  }
+
+  uint64_t m = l + ((msb64(sz) == sz) ? (sz >> 1) : msb64(sz));
+  switch (CUR->state) {
+  case PAGE_FREE:
+    if (req == sz) {
+      LOG("page allocated");
+      LOG(l);
+      DEBUG_MEM(r);
+      CUR->state = PAGE_ALLOCATED;
+      CUR->maxsz = 0;
+      return l;
+    }
+    LCH->state = RCH->state = PAGE_FREE;
+    LCH->maxsz = msb64(m - l);
+    RCH->maxsz = msb64(r - m);
+    break;
+  case PAGE_DIVIDED:
+    break;
+  case PAGE_ALLOCATED:
+  case PAGE_RESERVED:
+    return MMAN_NO_PAGE;
+  default:
+    exit(ERR_UNREACHABLE);
+  }
+
+  uint64_t ret = MMAN_NO_PAGE;
+  if (ret == MMAN_NO_PAGE && LCH->maxsz >= req)
+    ret = _allocate_page(req, LIDX, l, m);
+  if (ret == MMAN_NO_PAGE && RCH->maxsz >= req)
+    ret = _allocate_page(req, RIDX, m, r);
+  _pull(idx, sz);
+  return ret;
+}
+
+void *allocate_page(size_t page_cnt)
+{
+  if (msb64(page_cnt) != page_cnt)
+    exit(ERR_INVALID_OP);
+
+  uint64_t offset = _allocate_page(page_cnt, 0, 0, mman_page_cnt);
+  
+  if (offset == MMAN_NO_PAGE)
+    exit(ERR_NO_MEM);
+    // return (void *)0x0;
+
+  return mman_memory_start + offset * (1 << 12);
+}
+
+static inline
+void _free_page(uint64_t req, int idx, uint64_t l, uint64_t r)
+{
+  uint64_t sz = r - l;
+
+  switch (CUR->state) {
+  case PAGE_FREE:
+    return;
+  case PAGE_ALLOCATED:
+    if (req == l) {
+      LOG("page freed");
+      LOG(l);
+      DEBUG_MEM(r);
+      CUR->state = PAGE_FREE;
+      CUR->maxsz = sz;
+      return;
+    }
+  case PAGE_DIVIDED:
+    break;
+  case PAGE_RESERVED:
+  default:
+    exit(ERR_UNREACHABLE);
+  }
+
+  uint64_t m = l + ((msb64(sz) == sz) ? (sz >> 1) : msb64(sz));
+  if (l <= req && req < m)
+    _free_page(req, LIDX, l, m);
+  if (m <= req && req < r)
+    _free_page(req, RIDX, m, r);
+  _pull(idx, sz);
+}
+
+void free_page(void *page)
+{
+  if (ALIGN4K(page) != page)
+    exit(ERR_INVALID_OP);
+
+  uint64_t start = ((uint64_t)page - (uint64_t)mman_memory_start) >> 12;
+  _free_page(start, 0, 0, mman_page_cnt); 
+}
+
+static inline
+void _reserve_page(uint64_t ql, uint64_t qr, int idx, uint64_t l, uint64_t r)
+{
+  if (qr <= l || r <= ql)
+    return;
+
+  uint64_t sz = r - l;
+  if (ql <= l && r <= qr && msb64(sz) == sz) {
+    if (CUR->state == PAGE_RESERVED)
+      return;
+    if (CUR->state != PAGE_FREE)
+      exit(ERR_INVALID_MEM);
+
+    LOG("page reserved");
+    LOG(l);
+    DEBUG_MEM(r);
+    CUR->state = PAGE_RESERVED;
+    CUR->maxsz = 0;
+    return;
+  }
+
+  uint64_t m = l + ((msb64(sz) == sz) ? (sz >> 1) : msb64(sz));
+  if (CUR->state == PAGE_FREE) {
+    LCH->state = RCH->state = PAGE_FREE;
+    LCH->maxsz = msb64(m - l);
+    RCH->maxsz = msb64(r - m);
+  }
+
+  if (ql < m)
+    _reserve_page(ql, qr, LIDX, l, m);
+  if (m < qr)
+    _reserve_page(ql, qr, RIDX, m, r);
+  _pull(idx, sz);
+}
+
+void reserve_page(void *begin, void *end)
+{
+  uint64_t ql = ((uint64_t)begin - (uint64_t)mman_memory_start) >> 12;
+  uint64_t qr = (((uint64_t)end - (uint64_t)mman_memory_start - 1) >> 12) + 1;
+  
+  LOG("reserve page");
+  LOG(ql);
+  DEBUG_MEM(qr);
+  _reserve_page(ql, qr, 0, 0, mman_page_cnt);
+}

kernel/lib/queue.c

@@ -0,0 +1,57 @@
+#include <queue.h>
+#include <errcode.h>
+#include <utils.h>
+#include <kmalloc.h>
+
+queue_t *make_queue()
+{
+  queue_t *ret = kmalloc(sizeof(queue_t));
+  ret->size = 0;
+  ret->begin = kmalloc(sizeof(queue_node_t));
+  ret->end = kmalloc(sizeof(queue_node_t));
+  *ret->begin = *ret->end = (queue_node_t){
+    .prev = (queue_node_t *)ret->begin,
+    .next = (queue_node_t *)ret->end,
+    .value = 0,
+  };
+
+  return ret;
+}
+
+uint64_t queue_back(const queue_t *queue)
+{
+  if (!queue->size)
+    exit(ERR_OUT_OF_BOUND);
+  return queue->end->prev->value;
+}
+
+uint64_t queue_front(const queue_t *queue)
+{
+  if (!queue->size)
+    exit(ERR_OUT_OF_BOUND);
+  return queue->begin->next->value;
+}
+
+void queue_push_back(queue_t *queue, uint64_t val)
+{
+  queue->end->value = val;
+  queue->end->next = kmalloc(sizeof(queue_node_t));
+  *queue->end->next = (queue_node_t){
+    .prev = queue->end,
+    .next = queue->end->next,
+    .value = 0,
+  };
+  queue->end = queue->end->next;
+}
+
+void queue_push_front(queue_t *queue, uint64_t val)
+{
+  queue->begin->value = val;
+  queue->begin->prev = kmalloc(sizeof(queue_node_t));
+  *queue->begin->prev = (queue_node_t){
+    .prev = queue->begin->prev,
+    .next = queue->begin,
+    .value = 0,
+  };
+  queue->begin = queue->begin->prev;
+}

kernel/lib/ringbuffer.c

@@ -0,0 +1,55 @@
+#include <ringbuffer.h>
+#include <utils.h>
+#include <errcode.h>
+#include <stddef.h>
+#include <kmalloc.h>
+
+ringbuffer_t *make_ringbuffer(size_t size)
+{
+  ringbuffer_t *ret = kmalloc(sizeof(ringbuffer_t));
+  uint8_t *data = kmalloc(size * sizeof(uint8_t));
+  *ret = (ringbuffer_t){
+    .size = 0,
+    .cap = size,
+    .data = data,
+    .read = data,
+    .write = data,
+  };
+  return ret;
+}
+
+int ringbuffer_push(ringbuffer_t *buf, uint8_t val)
+{
+  if (buf->size == buf->cap)
+    return ERR_OUT_OF_BOUND;
+
+  *buf->write++ = val;
+
+  if (buf->write == buf->data + buf->cap)
+    buf->write = buf->data;
+
+  ++buf->size;
+  return NO_ERROR;
+}
+
+uint8_t ringbuffer_bump(ringbuffer_t *buf)
+{
+  if (buf->size == 0)
+    exit(ERR_INVALID_OP);
+
+  uint8_t ret = *buf->read++;
+
+  if (buf->read == buf->data + buf->cap)
+    buf->read = buf->data;
+
+  --buf->size;
+  return ret;
+}
+
+uint8_t ringbuffer_peek(ringbuffer_t *buf)
+{
+  if (buf->size == 0)
+    exit(ERR_INVALID_OP);
+
+  return *buf->read;
+}

kernel/lib/shell.c

@@ -0,0 +1,231 @@
+#include <stddef.h>
+#include <logger.h>
+#include <timer.h>
+#include <errcode.h>
+#include <kmalloc.h>
+#include <utils.h>
+#include <string.h>
+#include <uart.h>
+#include <mbox.h>
+#include <shell.h>
+#include <exec.h>
+#include <mman.h>
+
+#define INPUT_BUFLEN 1000
+
+#define PM_PASSWORD 0x5a000000
+
+#define PM_RSTC 0x3F10001c
+#define PM_WDOG 0x3F100024
+
+static inline
+void _help (void)
+{
+  uart_puts(
+    "help                         : print this help menu" ENDL
+    "hello                        : print Hello World!" ENDL
+    "hwinfo                       : print hardware info" ENDL
+    "memalloc   <size>            : alloate memory and print" ENDL
+    "ls                           : list directory contents" ENDL
+    "cat        <file>            : concatenate files and print" ENDL
+    "exec       <file>            : execute file in usermode" ENDL
+    "settimeout <sec> <message...>: pring message after a few seconds" ENDL
+    "reboot                       : reboot the device" ENDL
+  );
+}
+
+static inline
+void _hello (void)
+{
+  uart_puts("hello, world" ENDL);
+}
+
+static inline
+void _hwinfo (void)
+{
+  uart_puts(
+    "hwinfo: " ENDL
+    "board revision: "
+  );
+  uart_hex(get_board_revision());
+  uart_puts(
+    ENDL
+    "memory base addr: "
+  );
+  uart_hex(get_memory_base_addr());
+  uart_puts(
+    ENDL
+    "memory size: "
+  );
+  uart_hex(get_memory_size());
+  uart_puts(ENDL);
+}
+
+static inline
+void _memalloc(size_t size)
+{
+  void *addr = kmalloc(size);
+  uart_puts("size: ");
+  uart_hex(size);
+  uart_puts(ENDL);
+
+  uart_puts("addr: ");
+  uart_hex((uint64_t)addr);
+  uart_puts(ENDL);
+}
+
+static inline
+void _ls_initrd_callback(file_node_t *tr)
+{
+  uart_puts(tr->filename);
+  uart_puts(ENDL);
+}
+
+static inline
+void _ls(file_node_t *root)
+{
+  initrd_traverse(root, _ls_initrd_callback);
+}
+
+static inline
+void _cat(file_node_t *root, const char *filename)
+{
+  file_node_t *tr = initrd_get(root, filename);
+  if (tr) {
+    uart_puts((char *)tr->filecontent);
+  } else {
+    exit(ERR_NOT_EXIST);
+  }
+}
+
+static inline
+void _exec(file_node_t *root, const char *filename)
+{
+  file_node_t *tr = initrd_get(root, filename);
+  if (tr) {
+    void *userspace = allocate_page(1 << 6);
+    memcpy(userspace, tr->filecontent, tr->filesize);
+    user_exec(userspace, userspace + (1 << (12 + 6)) - 8);
+    kfree(userspace);
+  } else {
+    exit(ERR_NOT_EXIST);
+  }
+}
+
+static inline
+void _settimeout_cb_func(uint64_t args)
+{
+  vector_t *v = (void *)args;
+  for (int i = 2; i < (int)v->size; ++i) {
+    uart_puts(VEC_AT(char, v, i));
+    uart_puts(" ");
+  }
+  uart_puts(ENDL);
+}
+
+static inline
+void _settimeout(int32_t sec, vector_t *args)
+{
+  uint64_t cntpct_el0, cntfrq_el0;
+  R_SYSREG(cntpct_el0, cntpct_el0);
+  R_SYSREG(cntfrq_el0, cntfrq_el0);
+
+  task_t task = (task_t){
+    .firing_tick = cntpct_el0 + sec * cntfrq_el0,
+    .interval = sec * cntfrq_el0,
+    .repeat = 1,
+
+    .func = _settimeout_cb_func,
+    .param = (uint64_t)args,
+  };
+  add_task(task);
+}
+
+static inline
+void _set(long addr, unsigned int value) {
+  volatile unsigned int* point = (unsigned int*)addr;
+  *point = value;
+}
+
+static inline
+void _reset(int tick) {               // reboot after watchdog timer expire
+  _set(PM_RSTC, PM_PASSWORD | 0x20);  // full reset
+  _set(PM_WDOG, PM_PASSWORD | tick);  // number of watchdog tick
+}
+
+static inline
+void _reboot(void)
+{
+  _reset(1 << 16);
+}
+
+char *_shell_buf = (char *)0x0;
+int _shell_sz = 0;
+
+static inline
+int _shell_operations(char ch)
+{
+  switch (ch) {
+  case 0x7f:
+    if (_shell_sz > 0) {
+      --_shell_sz;
+      uart_puts("\b \b");
+    }
+    return true;
+  default:
+  }
+  return false;
+}
+
+int shell(file_node_t *initrd_root)
+{
+  uart_puts("# ");
+  char ch;
+  _shell_buf = kmalloc(INPUT_BUFLEN * sizeof(char));
+  _shell_sz = 0;
+  while ((ch = uart_getc()) != '\n') {
+    if (_shell_operations(ch))
+      continue;
+    _shell_buf[_shell_sz++] = ch;
+    uart_putb((const uint8_t *)&ch, 1);
+  }
+  uart_puts(ENDL);
+  _shell_buf[_shell_sz] = ' ';
+
+  vector_t *args = make_vector(0);
+  for (char *saveptr = 0x0, *tok = strtok_r(_shell_buf, " ", &saveptr);
+       tok; tok = strtok_r((char *)0x0, " ", &saveptr)) {
+    VEC_PUSH(args, tok);
+    LOG(tok);
+  }
+
+  // DEBUG("ENDL");
+  CLEAN;
+
+  char *cmd = args->size ? VEC_AT(char, args, 0) : (char *)0x0;
+  if (!strcmp(cmd, "help")) {
+    _help();
+  } else if (!strcmp(cmd, "hello")) {
+    _hello();
+  } else if (!strcmp(cmd, "hwinfo")) {
+    _hwinfo();
+  } else if (!strcmp(cmd, "memalloc") && args->size >= 2){
+    char *p1 = VEC_AT(char, args, 1);
+    _memalloc((size_t)atoi32(p1));
+  } else if (!strcmp(cmd, "ls")) {
+    _ls(initrd_root);
+  } else if (!strcmp(cmd, "cat") && args->size >= 2) {
+    char *p1 = VEC_AT(char, args, 1);
+    _cat(initrd_root, p1);
+  } else if (!strcmp(cmd, "exec") && args->size >= 2) {
+    char *p1 = VEC_AT(char, args, 1);
+    _exec(initrd_root, p1);
+  } else if (!strcmp(cmd, "settimeout") && args->size >= 2) {
+    char *p1 = VEC_AT(char, args, 1);
+    _settimeout(atoi32(p1), args);
+  } else if (!strcmp(cmd, "reboot")) {
+    _reboot();
+  }
+  
+  return true;
+}

kernel/lib/timer.c

@@ -0,0 +1,108 @@
+#include <timer.h>
+#include <interrupt.h>
+#include <logger.h>
+#include <utils.h>
+#include <kmalloc.h>
+
+#define CORE0_TIMER_IRQ_CTRL ((volatile uint32_t *)0x40000040)
+
+timer_t *global_timer = (timer_t *)0x0;
+
+MMIO_W_HELPER(_enable_timer_irq, CORE0_TIMER_IRQ_CTRL, 0x1, 1);
+
+static inline
+uint32_t _d(timer_t *t)
+{ return t ? t->_d : 0; }
+
+static inline
+void _swap(timer_t **a, timer_t **b)
+{
+  timer_t *tmp = *a;
+  *a = *b, *b = tmp;
+}
+
+static inline
+timer_t *_merge(timer_t *a, timer_t *b)
+{
+  if (!a || !b)
+    return a ?: b;
+  
+  if (a->data.firing_tick > b->data.firing_tick)
+    _swap(&a, &b);
+  a->_r = _merge(a->_r, b);
+
+  if (_d(a->_l) < _d(a->_r))
+    _swap(&a->_l, &a->_r);
+  
+  a->_d = _d(a->_r) + 1;
+  return a;
+}
+
+static inline
+timer_t *_pop(timer_t *t)
+{
+  if (!t || (!t->_l && !t->_r))
+    return (timer_t *)0x0;
+  return _merge(t->_l, t->_r);
+}
+
+static inline
+void _set_timer_interrrupt()
+{
+  if (global_timer) {
+    uint64_t cntpct_el0;
+    R_SYSREG(cntpct_el0, cntpct_el0);
+    DEBUG_EXCEP(cntpct_el0);
+
+    uint64_t firing_tick = MAX(global_timer->data.firing_tick, cntpct_el0);
+    W_SYSREG(cntp_cval_el0, firing_tick);
+    
+    _enable_timer_irq(true);
+  }
+}
+
+static inline
+void _traverse(timer_t *t)
+{
+  if (!t) return;
+  DEBUG_EXCEP(t->data.firing_tick);
+  t->data.func(t->data.param);
+  _traverse(t->_l);
+  _traverse(t->_r);
+}
+
+void add_task(task_t task)
+{
+  DEBUG_EXCEP("add task");
+  timer_t *newtimer = kmalloc(sizeof(timer_t));
+  *newtimer = (timer_t){
+    ._l = (timer_t *)0x0,
+    ._r = (timer_t *)0x0,
+    ._d = 0,
+
+    .data = task,
+  };
+
+  global_timer = _merge(global_timer, newtimer);
+
+  _traverse(global_timer);
+  _set_timer_interrrupt();
+}
+
+void timer_irq_handler(void)
+{
+  _enable_timer_irq(false);
+
+  LOG("timer irq");
+
+  uint64_t cntpct_el0;
+  R_SYSREG(cntpct_el0, cntpct_el0);
+  DEBUG_EXCEP(cntpct_el0);
+
+  if (global_timer) {
+    add_interrupt_task(20, global_timer->data.func, global_timer->data.param);
+    global_timer = _pop(global_timer);
+  }
+
+  _set_timer_interrrupt();
+}

kernel/lib/uart.c

@@ -0,0 +1,211 @@
+#include <uart.h>
+#include <kmalloc.h>
+#include <interrupt.h>
+#include <logger.h>
+#include <errcode.h>
+#include <utils.h>
+#include <string.h>
+#include <gpio.h>
+#include <stddef.h>
+#include <ringbuffer.h>
+
+/* Auxilary mini UART registers */
+#define AUX_ENABLE      ((volatile uint32_t*)(MMIO_BASE + 0x00215004))
+#define AUX_MU_IO       ((volatile uint32_t*)(MMIO_BASE + 0x00215040))
+#define AUX_MU_IER      ((volatile uint32_t*)(MMIO_BASE + 0x00215044))
+#define AUX_MU_IIR      ((volatile uint32_t*)(MMIO_BASE + 0x00215048))
+#define AUX_MU_LCR      ((volatile uint32_t*)(MMIO_BASE + 0x0021504C))
+#define AUX_MU_MCR      ((volatile uint32_t*)(MMIO_BASE + 0x00215050))
+#define AUX_MU_LSR      ((volatile uint32_t*)(MMIO_BASE + 0x00215054))
+#define AUX_MU_MSR      ((volatile uint32_t*)(MMIO_BASE + 0x00215058))
+#define AUX_MU_SCRATCH  ((volatile uint32_t*)(MMIO_BASE + 0x0021505C))
+#define AUX_MU_CNTL     ((volatile uint32_t*)(MMIO_BASE + 0x00215060))
+#define AUX_MU_STAT     ((volatile uint32_t*)(MMIO_BASE + 0x00215064))
+#define AUX_MU_BAUD     ((volatile uint32_t*)(MMIO_BASE + 0x00215068))
+
+#define ARMINT_En_IRQs1 ((volatile uint32_t*)(MMIO_BASE + 0x0000b210))
+
+size_t (*uart_putb)(const uint8_t *bytes, size_t len) = uart_putb_sync;
+size_t (*uart_getb)(uint8_t *bytes, size_t len)       = uart_getb_sync;
+int is_uart_inited = false;
+
+ringbuffer_t *uart_readbuf;
+ringbuffer_t *uart_writebuf;
+
+MMIO_W_HELPER(_uart_enable_receive_interrupt,  AUX_MU_IER, 0x1, 0);
+MMIO_W_HELPER(_uart_enable_transmit_interrupt, AUX_MU_IER, 0x1, 1);
+MMIO_W_HELPER(_uart_clear_receive_fifo,  AUX_MU_IIR, 0x1, 1);
+MMIO_W_HELPER(_uart_clear_transmit_fifo, AUX_MU_IIR, 0x1, 2);
+MMIO_W_HELPER(_uart_write_data, AUX_MU_IO, 0xff, 0);
+MMIO_W_HELPER(_uart_interrupt_controller, ARMINT_En_IRQs1, 0x1, 29);
+
+MMIO_R_HELPER(_uart_interrupt_pending,  AUX_MU_IIR, 0x1, 0);
+MMIO_R_HELPER(_uart_transmit_interrupt, AUX_MU_IIR, 0x1, 1);
+MMIO_R_HELPER(_uart_receive_interrupt,  AUX_MU_IIR, 0x1, 2);
+MMIO_R_HELPER(_uart_transmitter_idle, AUX_MU_LSR, 0x1, 5);
+MMIO_R_HELPER(_uart_data_ready,       AUX_MU_LSR, 0x1, 0);
+MMIO_R_HELPER(_uart_read_data, AUX_MU_IO, 0xff, 0);
+
+void uart_init(void)
+{
+  register uint32_t r;
+
+  /* initialize UART */
+  *AUX_ENABLE |= 1;      // enable UART1, AUX mini uart
+  *AUX_MU_CNTL = 0;      // disable Tx, Rx
+  *AUX_MU_LCR  = 3;      // set 8 bits
+  *AUX_MU_MCR  = 0;
+  *AUX_MU_IER  = 0;      // disable interrupt by default
+  *AUX_MU_IIR  = 0x6;    // clear tx, rx FIFO
+  *AUX_MU_BAUD = 270;    // 115200 baud
+  /* map UART1 to GPIO pins */
+  r = *GPFSEL1;
+  r &= ~((7 << 12) | (7 << 15)); // gpio14, gpio15
+  r |= (2 << 12) | (2 << 15);    // alt5
+  *GPFSEL1 = r;
+  *GPPUD = 0;            // enable pins 14 and 15
+  r = 150; while (r--) { asm volatile("nop"); }
+  *GPPUDCLK0 = (1 << 14) | (1 << 15);
+  r = 150; while (r--) { asm volatile("nop"); }
+  *GPPUDCLK0 = 0;        // flush GPIO setup
+  *AUX_MU_CNTL = 3;      // enable Tx, Rx
+  _uart_interrupt_controller(true);
+
+  uart_readbuf = make_ringbuffer(UART_BUFLEN);
+  uart_writebuf = make_ringbuffer(UART_BUFLEN);
+
+  _uart_enable_receive_interrupt(true);
+  //uint64_t ier = *AUX_MU_IER;
+
+  uart_getb = uart_getb_async;
+  uart_putb = uart_putb_async;
+
+  is_uart_inited = true;
+}
+
+void uart_transmit_interrupt_handler()
+{
+  if (uart_writebuf->size > 0)
+    _uart_write_data(ringbuffer_bump(uart_writebuf));
+}
+
+typedef struct {
+  ringbuffer_t *buf;
+  uint8_t val;
+} uart_interrupt_callback_payload_t;
+
+static inline
+void uart_receive_interrupt_callback(uint64_t param)
+{
+  uart_interrupt_callback_payload_t *payload = (void *)param;
+  ringbuffer_push(payload->buf, payload->val);
+  kfree(payload);
+}
+
+void uart_receive_interrupt_handler()
+{
+  if (uart_readbuf->size < uart_readbuf->cap) {
+    uint8_t b = _uart_read_data();
+
+    uart_interrupt_callback_payload_t *param = kmalloc(
+        sizeof(uart_interrupt_callback_payload_t));
+    *param = (uart_interrupt_callback_payload_t){
+      .buf = uart_readbuf,
+      .val = b,
+    };
+    add_interrupt_task(10, uart_receive_interrupt_callback, (uint64_t)param);
+  }
+}
+
+void uart_irq_handler(void)
+{
+  _uart_enable_receive_interrupt(false);
+  _uart_enable_transmit_interrupt(false);
+  if (_uart_receive_interrupt())
+    uart_receive_interrupt_handler();
+  if (_uart_transmit_interrupt())
+    uart_transmit_interrupt_handler();
+  
+  _uart_enable_receive_interrupt(true);
+  if (uart_writebuf->size > 0)
+    _uart_enable_transmit_interrupt(true);
+}
+
+size_t uart_putb_async(const uint8_t *bytes, size_t len)
+{
+  size_t sentlen = 0;
+  for (; sentlen < len; ++bytes, ++sentlen)
+    ringbuffer_push(uart_writebuf, *bytes);
+  
+  if (uart_writebuf->size > 0)
+    _uart_enable_transmit_interrupt(true);
+
+  return sentlen;
+}
+
+size_t uart_putb_sync(const uint8_t *bytes, size_t len)
+{
+  size_t sentlen = 0;
+  for (; sentlen < len; ++bytes, ++sentlen) {
+    do asm volatile("nop"); // busy waiting
+    while (!_uart_transmitter_idle());
+
+    _uart_write_data(*bytes);
+  }
+
+  return sentlen;
+}
+
+size_t uart_getb_async(uint8_t *bytes, size_t len)
+{
+  size_t recvlen = 0;
+  for (; recvlen < len; ++bytes, ++recvlen) {
+    while (!uart_readbuf->size)
+      wfe(); // wait for interrupt
+  
+    *bytes = ringbuffer_bump(uart_readbuf);
+  }
+
+  return recvlen;
+}
+
+size_t uart_getb_sync(uint8_t *bytes, size_t len)
+{
+  size_t recvlen = 0;
+  for (; recvlen < len; ++bytes, ++recvlen) {
+    do asm volatile("nop");
+    while (!_uart_data_ready());
+
+    *bytes = _uart_read_data();
+  }
+
+  return recvlen;
+}
+
+char uart_getc(void)
+{
+  char r;
+  uart_getb((uint8_t *)&r, 1);
+  return r == '\r' ? '\n' : r;
+}
+
+void uart_puts(const char *s)
+{
+  size_t len = strlen(s);
+  size_t ret = uart_putb((const uint8_t *)s, len);
+  if (ret != len)
+    exit(ERR_IO_FAILED);
+}
+
+void uart_hex(uint64_t d)
+{
+  char buf[0x11], *p = buf;
+  uint64_t n;
+  for (int c = 28; c >= 0; c -= 4) {
+    n = (d >> c) & 0xf;
+    n += n > 9 ? (char)'A' : (char)'0';
+    *p++ = n;
+  }
+  *p = '\0';
+  uart_puts(buf);
+}

kernel/lib/utils.c

@@ -4,18 +4,24 @@
 
 uint32_t msb32(uint32_t x)
 {
-  static const int msb[32] = {
-    0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30,
-    8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31
-  };
+  uint32_t res = 0x0;
+  asm volatile(
+    "clz %[res], %[val]"
+    : [res] "=r" (res)
+    : [val] "r"  (x)
+  );
+  return res == 32 ? 0 : (1 << (31 - res));
+}
 
-  x |= x >> 1;
-  x |= x >> 2;
-  x |= x >> 4;
-  x |= x >> 8;
-  x |= x >> 16;
-  
-  return msb[(uint32_t)(x * 0x07c4acddu) >> 27];
+uint64_t msb64(uint64_t x)
+{
+  uint64_t res = 0x0;
+  asm volatile(
+    "clz %[res], %[val]"
+    : [res] "=r" (res)
+    : [val] "r"  (x)
+  );
+  return res == 64 ? 0 : ((uint64_t)1 << (63 - res));
 }
 
 uint32_t hton32(const uint32_t h)

kernel/lib/vector.c

@@ -21,12 +21,12 @@ vector_t *make_vector(size_t size)
 uint64_t vec_at(const vector_t *vec, size_t idx)
 {
   if (idx >= vec->size)
-    exit(ERR_VECTOR_OOR);
+    exit(ERR_OUT_OF_BOUND);
   
   return vec->data[idx];
 }
 
-vector_t *vec_push(vector_t *vec, uint64_t val)
+void vec_push(vector_t *vec, uint64_t val)
 {
   if (vec->size == vec->cap) {
     uint64_t *old = vec->data;
@@ -35,5 +35,4 @@ vector_t *vec_push(vector_t *vec, uint64_t val)
   }
 
   vec->data[vec->size++] = val;
-  return vec;
 }

kernel/linker.ld

@@ -25,9 +25,11 @@ SECTIONS
     __bss_end = .;
   } >DATA
 
-  __stack_end = ORIGIN(RAM) + LENGTH(RAM);
 }
 
-__heap_start = ORIGIN(RAM);
-__heap_end = ORIGIN(RAM) + 32M;
-__bss_size = (__bss_end - __bss_start)>>3;
+PROVIDE(__kernel_start = ORIGIN(TEXT));
+PROVIDE(__kernel_end = ORIGIN(DATA) + LENGTH(DATA));
+PROVIDE(__heap_start = ORIGIN(RAM));
+PROVIDE(__heap_end = ORIGIN(RAM) + 32M);
+PROVIDE(__stack_end = ORIGIN(RAM) + LENGTH(RAM));
+PROVIDE(__bss_size = (__bss_end - __bss_start)>>3);

kernel/main.c

@@ -1,25 +1,117 @@
+#include <logger.h>
+#include <timer.h>
+#include <kmalloc.h>
 #include <uart.h>
 #include <dtb.h>
 #include <initrd.h>
+#include <mman.h>
 #include <shell.h>
 #include <vector.h>
+#include <utils.h>
+#include <exception.h>
+#include <interrupt.h>
+
+void init(void *dtb, file_node_t **initrd_root)
+{
+  init_exception();
+
+  // UART
+  uart_init();
+
+  // Device tree
+  DEBUG_DTB(dtb);
+  dtb_start = dtb;
+  vector_t *dtb_struct_cbs = make_vector(0);
+  VEC_PUSH(dtb_struct_cbs, &initrd_dtb_cb);
+  VEC_PUSH(dtb_struct_cbs, &mman_dtb_memory_cb);
+  fdt_traverse(dtb_struct_cbs);
+  DEBUG_DTB("device tree parse done");
+
+  // Initramfs
+  DEBUG_INITRD(initrd_start);
+  *initrd_root = initrd_init();
+
+  // Memory (Buddy system)
+  mman_init();
+  
+  init_interrupt();
+}
+
+static inline
+void _print_time(uint64_t)
+{
+  uint64_t cntpct_el0, cntfrq_el0;
+  R_SYSREG(cntpct_el0, cntpct_el0);
+  R_SYSREG(cntfrq_el0, cntfrq_el0);
+  DEBUG_EXCEP(cntpct_el0 / cntfrq_el0);
+
+  task_t task = {
+    .firing_tick = cntpct_el0 + 2 * cntfrq_el0,
+    .interval = 2 * cntfrq_el0,
+    .repeat = 1,
+
+    .func = _print_time,
+    .param = 0x0,
+  };
+  
+  add_task(task);
+}
 
 void main(void *dtb)
 {
-  uart_init();
-  uart_getc();
-  
-  DEBUG(dtb);
+  file_node_t *initrd_root = 0x0;
+  init(dtb, &initrd_root);
 
-  dtb_addr = dtb;
-  vector_t *dtb_cbs = make_vector(0);
-  VEC_PUSH(dtb_cbs, &initrd_dtb_cb);
-  fdt_traverse(dtb_cbs);
+  // LOG("system booting in");
+  // _print_time(0x0);
 
-  DEBUG(initrd_start);
-  DEBUG(initrd_end);
+  uint64_t el;
+  R_SYSREG(el, CurrentEL);
+  INFOR(el);
 
-  file_node_t *initrd_root = initrd_init();
+  void *page1 = allocate_page(1);
+  INFOR(page1);
+
+  void *page2 = allocate_page(2);
+  INFOR(page2);
+
+  void *page4 = allocate_page(4);
+  INFOR(page4);
+
+  void *page16 = allocate_page(16);
+  INFOR(page16);
+
+  free_page(page1);
+  free_page(page2);
+  free_page(page4);
+  free_page(page16);
+
+  void *page32 = allocate_page(32);
+  INFOR(page32);
+  page1 = allocate_page(1);
+  INFOR(page1);
+
+  free_page(page1);
+
+  void *kmalloc8 = kmalloc(8);
+  INFOR(kmalloc8);
+  kfree(kmalloc8);
+
+  kmalloc8 = kmalloc(8);
+  INFOR(kmalloc8);
+  kfree(kmalloc8);
+
+  void *kmalloc7k = kmalloc(7 * (1 << 10));
+  INFOR(kmalloc7k);
+
+  void *kmalloc8k = kmalloc(1 << 13);
+  INFOR(kmalloc8k);
+
+  kfree(kmalloc7k);
+  kfree(kmalloc8k);
+
+  page1 = allocate_page(1);
+  INFOR(page1);
 
   int shell_cont = 1;
   while (shell_cont) {

lib/kmalloc.c

@@ -1,40 +0,0 @@
-#include <uart.h>
-#include <errcode.h>
-#include <utils.h>
-#include <kmalloc.h>
-#include <stddef.h>
-
-extern uint64_t __heap_start;
-extern uint64_t __heap_end;
-
-void *_heap_top = (void *)0;
-
-// simple 8-byte aligned linear allocation
-void *simple_alloc(size_t size)
-{
-  if (!_heap_top) {
-    _heap_top = (void *)&__heap_start;
-  }
-
-  if (size & 0xff)
-    size = (size & ~0xff) + 0x100;
-  
-  if ((uint64_t)_heap_top + size >= (uint64_t)&__heap_end)
-    exit(ERR_NO_MEM);
-
-  void *ret = _heap_top;
-  _heap_top = (void *)((uint64_t)_heap_top + size);
-
-  return ret;
-}
-
-void *kmalloc(size_t size)
-{
-  return simple_alloc(size);
-}
-
-void kfree(void *ptr)
-{
-  // not implemented for now
-  return;
-}

lib/logger.c

@@ -0,0 +1,4 @@
+#include <logger.h>
+
+char logger_buf[LOGGER_BUFLEN];
+char *logger_cur = logger_buf;

lib/shell.c

@@ -1,130 +0,0 @@
-#include <stddef.h>
-#include <utils.h>
-#include <string.h>
-#include <uart.h>
-#include <mbox.h>
-#include <shell.h>
-
-#define INPUT_BUFLEN 1000
-
-#define PM_PASSWORD 0x5a000000
-
-#define PM_RSTC 0x3F10001c
-#define PM_WDOG 0x3F100024
-
-void help (void)
-{
-  uart_puts(
-    "help  : print this help menu" ENDL
-    "hello : print Hello World!" ENDL
-    "hwinfo: print hardware info" ENDL
-    "ls    : list directory contents" ENDL
-    "cat   : concatenate files and print" ENDL
-    "reboot: reboot the device" ENDL
-  );
-}
-
-void hello (void)
-{
-  uart_puts("hello, world" ENDL);
-}
-
-void hwinfo (void)
-{
-  uart_puts(
-    "hwinfo: " ENDL
-    "board revision: "
-  );
-  uart_hex(get_board_revision());
-  uart_puts(
-    ENDL
-    "memory base addr: "
-  );
-  uart_hex(get_memory_base_addr());
-  uart_puts(
-    ENDL
-    "memory size: "
-  );
-  uart_hex(get_memory_size());
-  uart_puts(ENDL);
-}
-
-void ls_initrd_callback(file_node_t *tr)
-{
-  uart_puts(tr->filename);
-  uart_puts(ENDL);
-}
-
-void ls(file_node_t *root)
-{
-  initrd_traverse(root, ls_initrd_callback);
-}
-
-void cat(file_node_t *root, const char *filename)
-{
-  file_node_t *tr = initrd_get(root, filename);
-  if (tr) {
-    uart_puts((char *)tr->filecontent);
-  } else {
-    uart_puts("FILE NOT EXIST!" ENDL);
-  }
-}
-
-void set(long addr, unsigned int value) {
-    volatile unsigned int* point = (unsigned int*)addr;
-    *point = value;
-}
-
-void reset(int tick) {                 // reboot after watchdog timer expire
-    set(PM_RSTC, PM_PASSWORD | 0x20);  // full reset
-    set(PM_WDOG, PM_PASSWORD | tick);  // number of watchdog tick
-}
-
-void reboot(void)
-{
-  reset(1 << 16);
-}
-
-int shell(file_node_t *initrd_root)
-{
-  uart_puts("# ");
-
-  char buf[INPUT_BUFLEN], ch;
-  int sz = 0;
-  while ((ch = uart_getc()) != '\n') {
-    buf[sz++] = ch;
-    uart_send(ch);
-  }
-  uart_puts(ENDL);
-  buf[sz] = '\0';
-
-  const char *i = buf;
-
-  char bin[INPUT_BUFLEN], *j;
-  for (j = bin; *i != '\0' && !isspace(*i); ++i, ++j)
-    *j = *i;
-  *j = '\0';
-
-  for (; *i != '\0' && isspace(*i); ++i);
-
-  char param[INPUT_BUFLEN];
-  for (j = param; *i != '\0' && !isspace(*i); ++i, ++j)
-    *j = *i;
-  *j = '\0';
-
-  if (!strcmp(bin, "help")) {
-    help();
-  } else if (!strcmp(bin, "hello")) {
-    hello();
-  } else if (!strcmp(bin, "hwinfo")) {
-    hwinfo();
-  } else if (!strcmp(bin, "ls")) {
-    ls(initrd_root);
-  } else if (!strcmp(bin, "cat")) {
-    cat(initrd_root, param);
-  } else if (!strcmp(bin, "reboot")) {
-    reboot();
-  }
-  
-  return true;
-}

lib/string.c

@@ -35,6 +35,21 @@ size_t strlen(const char *str)
   return ret;
 }
 
+char *strtok_r(char *restrict str, const char *restrict delimiters,
+               char **restrict saveptr)
+{
+  if (str)
+    *saveptr = str;
+  for (char *ret = *saveptr; **saveptr != '\0'; ++(*saveptr)) {
+    for (int i = 0; delimiters[i] != '\0'; i++)
+      if (**saveptr == delimiters[i]) {
+        *(*saveptr)++ = '\0';
+        return ret;
+      }
+  }
+  return 0x0;
+}
+
 void *memcpy(void *dest, const void *src, size_t count)
 {
   void *ret = dest;

lib/uart.c

@@ -1,131 +0,0 @@
-#include <uart.h>
-#include <gpio.h>
-#include <stddef.h>
-
-/* Auxilary mini UART registers */
-#define AUX_ENABLE      ((volatile unsigned int*)(MMIO_BASE+0x00215004))
-#define AUX_MU_IO       ((volatile unsigned int*)(MMIO_BASE+0x00215040))
-#define AUX_MU_IER      ((volatile unsigned int*)(MMIO_BASE+0x00215044))
-#define AUX_MU_IIR      ((volatile unsigned int*)(MMIO_BASE+0x00215048))
-#define AUX_MU_LCR      ((volatile unsigned int*)(MMIO_BASE+0x0021504C))
-#define AUX_MU_MCR      ((volatile unsigned int*)(MMIO_BASE+0x00215050))
-#define AUX_MU_LSR      ((volatile unsigned int*)(MMIO_BASE+0x00215054))
-#define AUX_MU_MSR      ((volatile unsigned int*)(MMIO_BASE+0x00215058))
-#define AUX_MU_SCRATCH  ((volatile unsigned int*)(MMIO_BASE+0x0021505C))
-#define AUX_MU_CNTL     ((volatile unsigned int*)(MMIO_BASE+0x00215060))
-#define AUX_MU_STAT     ((volatile unsigned int*)(MMIO_BASE+0x00215064))
-#define AUX_MU_BAUD     ((volatile unsigned int*)(MMIO_BASE+0x00215068))
-
-int is_uart_init = 0;
-
-/**
- * Set baud rate and characteristics (115200 8N1) and map to GPIO
- */
-void uart_init()
-{
-    register unsigned int r;
-    
-    /* initialize UART */
-    *AUX_ENABLE |=1;       // enable UART1, AUX mini uart
-    *AUX_MU_IER = 0;
-    *AUX_MU_CNTL = 0;
-    *AUX_MU_LCR = 3;       // 8 bits
-    *AUX_MU_MCR = 0;
-    *AUX_MU_IER = 0;
-    *AUX_MU_IIR = 0xc6;    // disable interrupts
-    *AUX_MU_BAUD = 270;    // 115200 baud
-    /* map UART1 to GPIO pins */
-    r=*GPFSEL1;
-    r&=~((7<<12)|(7<<15)); // gpio14, gpio15
-    r|=(2<<12)|(2<<15);    // alt5
-    *GPFSEL1 = r;
-    *GPPUD = 0;            // enable pins 14 and 15
-    r=150; while(r--) { asm volatile("nop"); }
-    *GPPUDCLK0 = (1<<14)|(1<<15);
-    r=150; while(r--) { asm volatile("nop"); }
-    *GPPUDCLK0 = 0;        // flush GPIO setup
-    *AUX_MU_CNTL = 3;      // enable Tx, Rx
-
-    is_uart_init = 1;
-}
-
-/**
- * Send a character
- */
-void uart_send(unsigned int c) {
-    /* wait until we can send */
-    do{asm volatile("nop");}while(!(*AUX_MU_LSR&0x20));
-    /* write the character to the buffer */
-    *AUX_MU_IO=c;
-}
-
-uint8_t uart_getb()
-{
-  uint8_t r;
-  /* wait until something is in the buffer */
-  do{asm volatile("nop");}while(!(*AUX_MU_LSR&0x01));
-  /* read it and return */
-  r=(uint8_t)(*AUX_MU_IO);
-
-  return r;
-}
-
-/**
- * Receive a character
- */
-char uart_getc() {
-  char r = (char)uart_getb();
-
-  /* convert carrige return to newline */
-  return r=='\r'?'\n':r;
-}
-
-/**
- * Display a string
- */
-void uart_puts(const char *s) {
-    while(*s) {
-        /* convert newline to carrige return + newline */
-        if(*s=='\n')
-            uart_send('\r');
-        uart_send(*s++);
-    }
-}
-
-/**
- * Display a binary value in hexadecimal
- */
-void uart_hex(const unsigned int d) {
-    unsigned int n;
-    int c;
-    for(c=28;c>=0;c-=4) {
-        // get highest tetrad
-        n=(d>>c)&0xF;
-        // 0-9 => '0'-'9', 10-15 => 'A'-'F'
-        n+=n>9?0x37:0x30;
-        uart_send(n);
-    }
-}
-
-void uart_int(int d)
-{
-  unsigned int buf[11];
-  int size = 0;
- 
-  if (d == 0) {
-    uart_send((unsigned int)'0');
-    return;
-  }
-
-  int is_neg = (d < 0);
-
-  while (d != 0) {
-    buf[size++] = '0' + d % 10;
-    d /= 10;
-  }
-
-  if (is_neg)
-    uart_send((unsigned int)'-');
-  while (size--)
-    uart_send(buf[size]);
-}

scripts/upload.py

@@ -1,15 +0,0 @@
-from pwn import *
-
-kernel = open("kernel8.img", "rb").read()
-r = serialtube("/dev/ttyS5", convert_newlines=False)
-
-
-input("@")
-r.send(str(len(kernel))+"\n")
-#print(r.recv())
-#r.interactive()
-print(r.recvuntil(b") : "))
-r.send(kernel)
-
-
-r.interactive()

test.py

@@ -1,13 +0,0 @@
-#!/usr/bin/env -S python3
-from pwn import *
-from struct import pack
-
-print(sys.argv)
-
-if len(sys.argv) < 2:
-    print("no args for serial device")
-    exit()
-
-tube = serialtube(sys.argv[1], convert_newlines=False)
-
-tube.interactive()

upload.py

@@ -26,6 +26,8 @@ while True:
 
     r.send(kernel[len(kernel) // splitsize * splitsize:])
 
+    sleep(1)
+    r.send(b"\n")
     r.interactive()
 
     r.send(b"\nreboot\n")

userprog/Makefile

@@ -0,0 +1,39 @@
+MAKE := make
+MAKEFLAGS += -j 8
+
+ARCH := aarch64
+GNU := $(ARCH)-linux-gnu
+
+CC := $(GNU)-gcc
+CCFLAGS += -Wall -Wextra -O0 \
+					 -nostdinc -nostdlib -nostartfiles -nodefaultlibs \
+					 -Wno-unused-parameter -Wno-unused-value -Wno-main -g
+
+LD := $(GNU)-ld
+LDFLAGS += -g -nostdlib -no-pie
+OBJCOPY := $(GNU)-objcopy
+
+LD_SCRIPT := linker.ld
+SRCS := $(shell find . -name '*.[cS]')
+OBJS := $(SRCS:%=%.o)
+
+.PHONY: all
+
+all: userprog
+
+userprog: userprog.elf
+	$(OBJCOPY) -O binary $< $@
+
+userprog.elf: $(LD_SCRIPT) $(OBJS)
+	$(LD) -o $@ -T $(LD_SCRIPT) $(OBJS) $(LDFLAGS)
+
+%.S.o: %.S
+	mkdir -p $(dir $@)
+	$(CC) -c $< -o $@ $(CCFLAGS)
+
+%.c.o: %.c
+	mkdir -p $(dir $@)
+	$(CC) -c $< -o $@ $(CCFLAGS)
+
+clean:
+	-rm $(OBJS) userprog userprog.elf

userprog/Start.S

@@ -0,0 +1,11 @@
+.section ".text"
+.global _start
+_start:
+	mov x0, 0
+loop:
+	add x0, x0, 1
+	svc 0
+	cmp x0, 5
+	blt loop
+wait:
+	b wait

userprog/linker.ld

@@ -0,0 +1,18 @@
+ENTRY(_start)
+
+SECTIONS
+{
+    .text : { 
+        *(.text.start)
+        *(.text)
+    }
+    .rodata : {
+        *(.rodata)
+    }
+    .data : {
+        *(.data)
+    }
+    .bss : {
+        *(.bss)
+    }
+}