Feat: lab 3

README.md

@@ -1 +1 @@
-# osc2025/ytshih
+[![Review Assignment Due Date](https://classroom.github.com/assets/deadline-readme-button-22041afd0340ce965d47ae6ef1cefeee28c7c493a6346c4f15d667ab976d596c.svg)](https://classroom.github.com/a/lAsr-c9M)

include/logger.h

@@ -19,7 +19,7 @@ static inline char *_logger_string(char *dest, const char *src)
 }
 static inline char *_logger_hex(char *dest, uint64_t x)
 {
-  for (int n, c = 60; c >= 0; c -= 4) {
+  for (int n, c = 28; c >= 0; c -= 4) {
     n = (x >> c) & 0xf;
     n += (n > 9) ? 0x37 : 0x30;
     *dest++ = (char)n;
@@ -101,11 +101,11 @@ logger_cur = _Generic((msg), \
 // #define DEBUG_DTB(val) DEBUG(val)
 #define DEBUG_DTB(val) CLEAN
 
-// #define DEBUG_EXCEP(val) DEBUG(val)
-#define DEBUG_EXCEP(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_MEM(val) DEBUG(val)
+#define DEBUG_MEM(val) CLEAN
 
 // #define DEBUG_INITRD(val) DEBUG(val)
 #define DEBUG_INITRD(val) CLEAN

kernel/exception_table.S

@@ -2,7 +2,7 @@
 
 // save general registers to stack
 .macro save_all
-	sub sp, sp, 34 * 8
+	sub sp, sp, 36 * 8
 	stp x0, x1,   [sp, 16 * 0]
 	stp x2, x3,   [sp, 16 * 1]
 	stp x4, x5,   [sp, 16 * 2]
@@ -18,22 +18,17 @@
 	stp x24, x25, [sp, 16 * 12]
 	stp x26, x27, [sp, 16 * 13]
 	stp x28, x29, [sp, 16 * 14]
+	stp x30, lr,  [sp, 16 * 15]
 
   mrs x0, spsr_el1
   mrs x1, elr_el1
   mrs x2, esr_el1
-  stp x0, x1,   [sp, 16 * 15]
-  stp x2, lr,   [sp, 16 * 16]
+  stp x0, x1,   [sp, 16 * 16]
+  str x2,       [sp, 16 * 17]
 .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]
@@ -49,8 +44,14 @@
 	ldp x24, x25, [sp, 16 * 12]
 	ldp x26, x27, [sp, 16 * 13]
 	ldp x28, x29, [sp, 16 * 14]
+	ldp x30, lr,  [sp, 16 * 15]
 
-	add sp, sp, 34 * 8
+  mrs x0, spsr_el1
+  mrs x1, elr_el1
+  mrs x2, esr_el1
+  ldp x0, x1,   [sp, 16 * 16]
+  ldr x2,       [sp, 16 * 17]
+	add sp, sp, 36 * 8
 .endm
 
 _null_handler:

kernel/include/interrupt.h

@@ -11,8 +11,6 @@ typedef struct interrupt {
   uint64_t priority;
   interrupt_callback_func_t func;
   uint64_t param;
-
-  int is_start;
 } interrupt_t;
 
 void add_interrupt_task(uint64_t priority,

kernel/include/mman.h

@@ -19,11 +19,7 @@ typedef enum :uint8_t {
 
 typedef struct {
   page_state_t state;
-
-  // when state == PAGE_ALLOCATED or PAGE_RESERVED, size = 0
-  // when state == PAGE_FREE, size = r - l
-  // when state == PAGE_DIVIDED, size = LCH->size | RCH->size
-  uint64_t size;
+  uint64_t maxsz;
 } page_header_t;
 
 void mman_init();

kernel/include/timer.h

@@ -20,7 +20,7 @@ typedef struct timer {
   task_t data;
 } timer_t;
 
-void add_timer_task(task_t task);
+void add_task(task_t task);
 
 void timer_irq_handler(void);
 

kernel/include/utils.h

@@ -6,8 +6,6 @@
 uint32_t msb32(uint32_t);
 uint64_t msb64(uint64_t);
 
-uint64_t lsb64(uint64_t);
-
 uint32_t hton32(const uint32_t);
 uint32_t ntoh32(const uint32_t);
 

kernel/lib/exception.c

@@ -21,7 +21,7 @@ void not_implemented_handler()
 void synchronous_handler()
 {
   static int poop = 0;
-  if (poop++ > 10)
+  if (poop++ > 5)
     exit(ERR_ADMINKILL);
   DEBUG_EXCEP("synchronous caught");
   uint64_t x0 = 0x0;

kernel/lib/interrupt.c

@@ -73,27 +73,21 @@ void add_interrupt_task(uint64_t priority,
 
     .priority = priority,
     .func = func,
-    .param = param,
-
-    .is_start = false,
+    .param = param
   };
 
   global_interrupt_pool = _merge(global_interrupt_pool, newint);
-
-  while (global_interrupt_pool) {
-    // LOG("check interrupt"); DEBUG_EXCEP(global_interrupt_pool->priority);
-    if (global_interrupt_pool->is_start)
-      return;
-    global_interrupt_pool->is_start = true;
-    global_interrupt_pool->func(global_interrupt_pool->param);
-    global_interrupt_pool = _pop(global_interrupt_pool);
-  }
 }
 
 void init_interrupt(void)
 {
-  _enable_interrupt();
+  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)
@@ -110,11 +104,8 @@ void irq_handler(void)
 
 void wfe(void)
 {
-  return; // do nothing for now
-
   if (!global_interrupt_pool) {
-    // asm volatile("wfe");
-    asm volatile("nop");
+    asm volatile("wfe");
     return;
   }
 

kernel/lib/kmalloc.c

@@ -1,4 +1,4 @@
-#include <logger.h>
+#include <uart.h>
 #include <errcode.h>
 #include <utils.h>
 #include <kmalloc.h>

kernel/lib/mman.c

@@ -47,24 +47,23 @@ void _pull(int idx, size_t sz)
 {
   if (LCH->state == PAGE_FREE && RCH->state == PAGE_FREE) {
     if (CUR->state != PAGE_FREE) {
-      LOG("free page merged");
+      LOG("node merged");
       DEBUG_MEM((uint64_t)idx);
     }
     CUR->state = PAGE_FREE;
-    CUR->size = sz;
   }
   if (LCH->state != PAGE_FREE || RCH->state != PAGE_FREE)
     CUR->state = PAGE_DIVIDED;
   switch (CUR->state) {
   case PAGE_FREE:
-    CUR->size = sz;
+    CUR->maxsz = sz;
     break;
   case PAGE_DIVIDED:
-    CUR->size = LCH->size | RCH->size;
+    CUR->maxsz = MAX(LCH->maxsz, RCH->maxsz);
     break;
   case PAGE_ALLOCATED:
   case PAGE_RESERVED:
-    CUR->size = 0;
+    CUR->maxsz = 0;
     break;
   default:
     exit(ERR_UNREACHABLE);
@@ -86,7 +85,7 @@ void mman_init()
 
   mman_frame_array[0] = (page_header_t){
     .state = PAGE_FREE,
-    .size = mman_page_cnt,
+    .maxsz = msb64(mman_page_cnt),
   };
 
   fdt_reserve_entry_t *entry = 0x0;
@@ -110,7 +109,7 @@ 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->size) {
+  if (req > sz || req > CUR->maxsz) {
     return MMAN_NO_PAGE;
   }
 
@@ -118,15 +117,16 @@ uint64_t _allocate_page(size_t req, int idx, uint64_t l, uint64_t r)
   switch (CUR->state) {
   case PAGE_FREE:
     if (req == sz) {
-      LOG("page allocated"); LOG(l); DEBUG_MEM(r);
+      LOG("page allocated");
+      LOG(l);
+      DEBUG_MEM(r);
       CUR->state = PAGE_ALLOCATED;
-      CUR->size = 0;
+      CUR->maxsz = 0;
       return l;
     }
-    LOG("page divided"); LOG(l); DEBUG_MEM(r);
     LCH->state = RCH->state = PAGE_FREE;
-    LCH->size = m - l;
-    RCH->size = r - m;
+    LCH->maxsz = msb64(m - l);
+    RCH->maxsz = msb64(r - m);
     break;
   case PAGE_DIVIDED:
     break;
@@ -138,25 +138,10 @@ uint64_t _allocate_page(size_t req, int idx, uint64_t l, uint64_t r)
   }
 
   uint64_t ret = MMAN_NO_PAGE;
-
-  // Goto child where size >= req
-  // If both children can handle, choose the one that has the least significant
-  // bit that can handle.
-  // It both children are the same, choose the left one
-  int is_lch_valid = (LCH->size >= req);
-  int is_rch_valid = (RCH->size >= req);
-  if (is_lch_valid && is_rch_valid) {
-    if (lsb64(LCH->size & ~(req - 1)) <= lsb64(RCH->size & ~(req - 1)))
-      ret = _allocate_page(req, LIDX, l, m);
-    else
-      ret = _allocate_page(req, RIDX, m, r);
-  }
-
-  if (ret == MMAN_NO_PAGE && LCH->size >= req)
+  if (ret == MMAN_NO_PAGE && LCH->maxsz >= req)
     ret = _allocate_page(req, LIDX, l, m);
-  if (ret == MMAN_NO_PAGE && RCH->size >= req)
+  if (ret == MMAN_NO_PAGE && RCH->maxsz >= req)
     ret = _allocate_page(req, RIDX, m, r);
-  
   _pull(idx, sz);
   return ret;
 }
@@ -189,7 +174,7 @@ void _free_page(uint64_t req, int idx, uint64_t l, uint64_t r)
       LOG(l);
       DEBUG_MEM(r);
       CUR->state = PAGE_FREE;
-      CUR->size = sz;
+      CUR->maxsz = sz;
       return;
     }
   case PAGE_DIVIDED:
@@ -233,17 +218,15 @@ void _reserve_page(uint64_t ql, uint64_t qr, int idx, uint64_t l, uint64_t r)
     LOG(l);
     DEBUG_MEM(r);
     CUR->state = PAGE_RESERVED;
-    CUR->size = 0;
+    CUR->maxsz = 0;
     return;
   }
 
   uint64_t m = l + ((msb64(sz) == sz) ? (sz >> 1) : msb64(sz));
   if (CUR->state == PAGE_FREE) {
-    LOG("page divided"); LOG(l); DEBUG_MEM(r);
-    CUR->state = PAGE_DIVIDED;
     LCH->state = RCH->state = PAGE_FREE;
-    LCH->size = m - l;
-    RCH->size = r - m;
+    LCH->maxsz = msb64(m - l);
+    RCH->maxsz = msb64(r - m);
   }
 
   if (ql < m)

kernel/lib/ringbuffer.c

@@ -24,11 +24,11 @@ int ringbuffer_push(ringbuffer_t *buf, uint8_t val)
     return ERR_OUT_OF_BOUND;
 
   *buf->write++ = val;
+  ++buf->size;
 
   if (buf->write == buf->data + buf->cap)
     buf->write = buf->data;
 
-  ++buf->size;
   return NO_ERROR;
 }
 
@@ -38,18 +38,10 @@ uint8_t ringbuffer_bump(ringbuffer_t *buf)
     exit(ERR_INVALID_OP);
 
   uint8_t ret = *buf->read++;
+  --buf->size;
 
   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

@@ -30,7 +30,6 @@ void _help (void)
     "cat        <file>            : concatenate files and print" ENDL
     "exec       <file>            : execute file in usermode" ENDL
     "settimeout <sec> <message...>: pring message after a few seconds" ENDL
-    "time                         : print current time tick" ENDL
     "reboot                       : reboot the device" ENDL
   );
 }
@@ -75,14 +74,6 @@ void _memalloc(size_t size)
   uart_puts(ENDL);
 }
 
-static inline
-void _free(uint64_t ptr)
-{
-  kfree((void *)ptr);
-  LOG(ptr);
-  INFOR("has been freed");
-}
-
 static inline
 void _ls_initrd_callback(file_node_t *tr)
 {
@@ -125,7 +116,6 @@ static inline
 void _settimeout_cb_func(uint64_t args)
 {
   vector_t *v = (void *)args;
-  uart_puts("timeout: ");
   for (int i = 2; i < (int)v->size; ++i) {
     uart_puts(VEC_AT(char, v, i));
     uart_puts(" ");
@@ -148,22 +138,7 @@ void _settimeout(int32_t sec, vector_t *args)
     .func = _settimeout_cb_func,
     .param = (uint64_t)args,
   };
-  add_timer_task(task);
-}
-
-static inline
-void _time()
-{
-  uint64_t cntpct_el0, cntfrq_el0, cntp_cval_el0, cntp_tval_el0;
-  R_SYSREG(cntpct_el0, cntpct_el0);
-  R_SYSREG(cntfrq_el0, cntfrq_el0);
-  R_SYSREG(cntp_cval_el0, cntp_cval_el0);
-  R_SYSREG(cntp_tval_el0, cntp_tval_el0);
-
-  LOG(cntpct_el0);
-  LOG(cntfrq_el0);
-  LOG(cntp_cval_el0);
-  INFOR(cntp_tval_el0);
+  add_task(task);
 }
 
 static inline
@@ -184,41 +159,20 @@ 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;
+  char *buf = kmalloc(INPUT_BUFLEN * sizeof(char)), ch;
+  int sz = 0;
   while ((ch = uart_getc()) != '\n') {
-    if (_shell_operations(ch))
-      continue;
-    _shell_buf[_shell_sz++] = ch;
+    buf[sz++] = ch;
     uart_putb((const uint8_t *)&ch, 1);
   }
   uart_puts(ENDL);
-  _shell_buf[_shell_sz] = ' ';
+  buf[sz] = ' ';
 
   vector_t *args = make_vector(0);
-  for (char *saveptr = 0x0, *tok = strtok_r(_shell_buf, " ", &saveptr);
+  for (char *saveptr = 0x0, *tok = strtok_r(buf, " ", &saveptr);
        tok; tok = strtok_r((char *)0x0, " ", &saveptr)) {
     VEC_PUSH(args, tok);
     LOG(tok);
@@ -234,12 +188,9 @@ int shell(file_node_t *initrd_root)
     _hello();
   } else if (!strcmp(cmd, "hwinfo")) {
     _hwinfo();
-  } else if (!strcmp(cmd, "memalloc") && args->size >= 2) {
+  } else if (!strcmp(cmd, "memalloc") && args->size >= 2){
     char *p1 = VEC_AT(char, args, 1);
     _memalloc((size_t)atoi32(p1));
-  } else if (!strcmp(cmd, "free") && args->size >= 2) {
-    char *p1 = VEC_AT(char, args, 1); 
-    _free((uint64_t)atoh32(p1));
   } else if (!strcmp(cmd, "ls")) {
     _ls(initrd_root);
   } else if (!strcmp(cmd, "cat") && args->size >= 2) {
@@ -251,8 +202,6 @@ int shell(file_node_t *initrd_root)
   } else if (!strcmp(cmd, "settimeout") && args->size >= 2) {
     char *p1 = VEC_AT(char, args, 1);
     _settimeout(atoi32(p1), args);
-  } else if (!strcmp(cmd, "time")) {
-    _time();
   } else if (!strcmp(cmd, "reboot")) {
     _reboot();
   }

kernel/lib/timer.c

@@ -47,36 +47,23 @@ timer_t *_pop(timer_t *t)
 }
 
 static inline
-void _check_enable_timer()
+void _set_timer_interrrupt()
 {
   if (global_timer) {
     uint64_t cntpct_el0;
     R_SYSREG(cntpct_el0, cntpct_el0);
     DEBUG_EXCEP(cntpct_el0);
 
-    if (global_timer->data.firing_tick < cntpct_el0)
-      W_SYSREG(cntp_tval_el0, 1);
-    else
-      W_SYSREG(cntp_cval_el0, global_timer->data.firing_tick);
+    uint64_t firing_tick = MAX(global_timer->data.firing_tick, cntpct_el0);
+    W_SYSREG(cntp_cval_el0, firing_tick);
     
-    W_SYSREG(cntp_ctl_el0, 1);
-  } else
-    W_SYSREG(cntp_ctl_el0, 0);
+    _enable_timer_irq(true);
+  }
 }
 
-static inline
-void _traverse(timer_t *t)
+void add_task(task_t task)
 {
-  if (!t) return;
-  DEBUG_EXCEP(t->data.firing_tick);
-  t->data.func(t->data.param);
-  _traverse(t->_l);
-  _traverse(t->_r);
-}
-
-void add_timer_task(task_t task)
-{
-  DEBUG_EXCEP("add timer task");
+  DEBUG_EXCEP("add task");
   timer_t *newtimer = kmalloc(sizeof(timer_t));
   *newtimer = (timer_t){
     ._l = (timer_t *)0x0,
@@ -87,44 +74,23 @@ void add_timer_task(task_t task)
   };
 
   global_timer = _merge(global_timer, newtimer);
-
-  // _traverse(global_timer);
-  _check_enable_timer();
-}
-
-typedef struct {
-  interrupt_callback_func_t func;
-  uint64_t param;
-} _timer_task_wrapper_param_t;
-
-static inline
-void _timer_task_wrapper(uint64_t param)
-{
-  _timer_task_wrapper_param_t *data = (void *)param;
-  data->func(data->param);
-  kfree(data);
-
-  _enable_timer_irq(true);
+  _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);
-  LOG("timer irq"); DEBUG_EXCEP(cntpct_el0);
+  DEBUG_EXCEP(cntpct_el0);
 
   if (global_timer) {
-    _timer_task_wrapper_param_t *param =
-      kmalloc(sizeof(_timer_task_wrapper_param_t));
-    *param = (_timer_task_wrapper_param_t){
-      .func  = global_timer->data.func,
-      .param = global_timer->data.param,
-    };
-    add_interrupt_task(20, _timer_task_wrapper, (uint64_t)param);
-
+    add_interrupt_task(20, global_timer->data.func, global_timer->data.param);
     global_timer = _pop(global_timer);
-    _check_enable_timer();
   }
+
+  _set_timer_interrrupt();
 }

kernel/lib/uart.c

@@ -29,8 +29,6 @@ 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;
 
-int is_uart_in_interrupt_queue = false;
-
 ringbuffer_t *uart_readbuf;
 ringbuffer_t *uart_writebuf;
 
@@ -85,47 +83,37 @@ void uart_init(void)
   is_uart_inited = true;
 }
 
-static inline
-void _enable_uart_interrupt()
+void uart_transmit_interrupt_handler()
 {
-  _uart_enable_receive_interrupt(true);
   if (uart_writebuf->size > 0)
-    _uart_enable_transmit_interrupt(true);
+    _uart_write_data(ringbuffer_bump(uart_writebuf));
 }
 
+typedef struct {
+  ringbuffer_t *buf;
+  uint8_t val;
+} uart_interrupt_callback_payload_t;
+
 static inline
-void _uart_transmit_interrupt_callback(uint64_t)
+void uart_receive_interrupt_callback(uint64_t param)
 {
-  _uart_write_data(ringbuffer_bump(uart_writebuf));
-
-  is_uart_in_interrupt_queue = false;
-  _enable_uart_interrupt();
+  uart_interrupt_callback_payload_t *payload = (void *)param;
+  ringbuffer_push(payload->buf, payload->val);
+  kfree(payload);
 }
 
-static inline
-void _uart_transmit_interrupt_handler()
-{
-  if (uart_writebuf->size > 0) {
-    is_uart_in_interrupt_queue = true;
-    add_interrupt_task(11, _uart_transmit_interrupt_callback, 0x0);
-  }
-}
-
-static inline
-void _uart_receive_interrupt_callback(uint64_t)
-{
-  ringbuffer_push(uart_readbuf, _uart_read_data());
-
-  is_uart_in_interrupt_queue = false;
-  _enable_uart_interrupt();
-}
-
-static inline
-void _uart_receive_interrupt_handler()
+void uart_receive_interrupt_handler()
 {
   if (uart_readbuf->size < uart_readbuf->cap) {
-    is_uart_in_interrupt_queue = true;
-    add_interrupt_task(12, _uart_receive_interrupt_callback, 0x0);
+    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);
   }
 }
 
@@ -133,11 +121,14 @@ void uart_irq_handler(void)
 {
   _uart_enable_receive_interrupt(false);
   _uart_enable_transmit_interrupt(false);
-
   if (_uart_receive_interrupt())
-    _uart_receive_interrupt_handler();
+    uart_receive_interrupt_handler();
   if (_uart_transmit_interrupt())
-    _uart_transmit_interrupt_handler();
+    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)
@@ -146,8 +137,8 @@ size_t uart_putb_async(const uint8_t *bytes, size_t len)
   for (; sentlen < len; ++bytes, ++sentlen)
     ringbuffer_push(uart_writebuf, *bytes);
   
-  if (!is_uart_in_interrupt_queue && uart_writebuf)
-    _enable_uart_interrupt();
+  if (uart_writebuf->size > 0)
+    _uart_enable_transmit_interrupt(true);
 
   return sentlen;
 }
@@ -171,7 +162,6 @@ size_t uart_getb_async(uint8_t *bytes, size_t len)
   for (; recvlen < len; ++bytes, ++recvlen) {
     while (!uart_readbuf->size)
       wfe(); // wait for interrupt
-  
     *bytes = ringbuffer_bump(uart_readbuf);
   }
 
@@ -209,10 +199,11 @@ void uart_puts(const char *s)
 void uart_hex(uint64_t d)
 {
   char buf[0x11], *p = buf;
-  for (int c = 28, n; c >= 0; c -= 4) {
+  uint64_t n;
+  for (int c = 28; c >= 0; c -= 4) {
     n = (d >> c) & 0xf;
-    n += (n > 9) ? 0x37 : 0x30;
-    *p++ = (char)n;
+    n += n > 9 ? (char)'A' : (char)'0';
+    *p++ = n;
   }
   *p = '\0';
   uart_puts(buf);

kernel/lib/utils.c

@@ -24,19 +24,6 @@ uint64_t msb64(uint64_t x)
   return res == 64 ? 0 : ((uint64_t)1 << (63 - res));
 }
 
-uint64_t lsb64(uint64_t x)
-{
-  uint64_t res = 0x0;
-  asm volatile(
-    "rbit x0, %[val]" ENDL
-    "clz %[res], x0"
-    : [res] "=r" (res)
-    : [val] "r"  (x)
-    : "x0"
-  );
-  return res == 64 ? 0 : ((uint64_t)1 << res);
-}
-
 uint32_t hton32(const uint32_t h)
 {
   const uint8_t *p = (const void *)&h;
@@ -119,7 +106,7 @@ uint32_t atoh32(const char *s)
     exit(ERR_CONVERSION);
 
   uint32_t ret = 0;
-  for (int i = 8; i-- && *s != '\0'; ++s) {
+  for (int i = 8; i--; ++s) {
     if (!isxdigit(*s))
       exit(ERR_CONVERSION);
     ret <<= 4, ret |= (isdigit(*s) ? *s - '0' : 

kernel/main.c

@@ -14,6 +14,7 @@
 void init(void *dtb, file_node_t **initrd_root)
 {
   init_exception();
+  init_interrupt();
 
   // UART
   uart_init();
@@ -33,8 +34,6 @@ void init(void *dtb, file_node_t **initrd_root)
 
   // Memory (Buddy system)
   mman_init();
-  
-  init_interrupt();
 }
 
 static inline
@@ -54,7 +53,7 @@ void _print_time(uint64_t)
     .param = 0x0,
   };
   
-  add_timer_task(task);
+  add_task(task);
 }
 
 void main(void *dtb)
@@ -62,8 +61,8 @@ void main(void *dtb)
   file_node_t *initrd_root = 0x0;
   init(dtb, &initrd_root);
 
-  // LOG("system booting in");
-  // _print_time(0x0);
+  LOG("system booting in");
+  _print_time(0x0);
 
   uint64_t el;
   R_SYSREG(el, CurrentEL);