bootrom/flash-reset.s

   1 @-----------------------------------------------------------------------------
   2 @ This code is licensed to you under the terms of the GNU GPL, version 2 or,
   3 @ at your option, any later version. See the LICENSE.txt file for the text of
   4 @ the license.
   5 @-----------------------------------------------------------------------------
   6 @ Reset vector for running from FLASH
   7 @-----------------------------------------------------------------------------
   8
   9 .section .startup,"ax"
  10
  11 .arm
  12
  13 .global flashstart
  14 flashstart:
  15         b       reset
  16         b       undefined_instruction
  17         b       software_interrupt
  18         b       prefetch_abort
  19         b       data_abort
  20         b       . @reserved
  21         ldr     pc, [pc,#-0xF20]        @ IRQ - read the AIC
  22         b       fiq
  23
  24 reset:
  25         ldr     sp, =_stack_end         @ initialize stack pointer to top of RAM
  26
  27         @ copy bootloader to RAM (in case the user re-flashes the bootloader)
  28         ldr     r0, =__bootphase2_src_start__
  29         ldr     r1, =__bootphase2_start__
  30         ldr     r2, =__bootphase2_end__
  31 1:
  32         ldr     r3, [r0], #4
  33         str     r3, [r1], #4
  34         cmp     r1, r2
  35         blo     1b
  36
  37         ldr     r3, =ram_start          @ start address of RAM bootloader
  38         bx      r3                      @ jump to it
  39
  40         .ltorg
  41
  42 undefined_instruction:
  43         b       .
  44 software_interrupt:
  45         b       .
  46 prefetch_abort:
  47         b       .
  48 data_abort:
  49         b       .
  50 fiq:
  51         b       .