sys/core/exceptions.c

   1 #include "sysclk.h"
   2 #include <link.h>
   3 #include <led.h>
   4 #include <uart.h>
   5 #include <panic.h>
   6
   7 /* Initialize just enough to be able to handle a fault.  */
   8 __attribute__ ((noinline, used)) static void
   9 sys_init (void)
  10 {
  11   unsigned int *src, *dst;
  12
  13   /* Relocate .data section to SRAM  */
  14   src = &_data_lma_start;
  15   dst = &_data_vma_start;
  16
  17   while (dst < &_data_vma_end)
  18     *(dst++) = *(src++);
  19
  20   /* Initialize .bss  */
  21   dst = &_bss_vma_start;
  22
  23   while (dst < &_bss_vma_end)
  24     *(dst++) = 0;
  25
  26   led_init ();
  27   sysclk_init ();
  28   uart_init ();
  29 }
  30
  31 /* Startup  */
  32 __attribute__ ((naked, noreturn)) static void
  33 reset_handler (void)
  34 {
  35   /* Set FAULTMASK  */
  36   asm ("cpsid f");
  37
  38   /* This function is the core logic for reset_handler (). We just need it so
  39    * that when we jump to kentry the stack is empty.  */
  40   asm ("bl sys_init");
  41
  42   /* Clear FAULTMASK  */
  43   asm ("cpsie f");
  44
  45   /* Jump to kernel entry code. When reset_handler () is called we are already
  46    * running on Thread mode (Privileged), so we can just jump directly.  */
  47   asm ("b kentry");
  48 }
  49
  50 /* TODO write proper exception handlers, this is just a test  */
  51 __attribute__ ((noreturn)) static void
  52 fault_handler (void)
  53 {
  54   panic ("Fault");
  55 }
  56
  57 __attribute__ ((section (".vector_table"), used))
  58 static unsigned long const vector_table[] = {
  59   [0] = (unsigned long) &_sram_end,
  60   [1] = (unsigned long) reset_handler,
  61   [3] = (unsigned long) fault_handler, /* ???  */
  62   [6] = (unsigned long) fault_handler,
  63 };