mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-02 01:19:49 +00:00
08deb6d36f
The full start-up sequence (TPL->SPL->U-Boot) can be a bit confusing since each phase has its own 'start' file. Add comments to explain this. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
50 lines
958 B
ArmAsm
50 lines
958 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+ */
|
|
/*
|
|
* 32-bit x86 Startup Code when running from TPL. This is the startup code in
|
|
* SPL, when TPL is used.
|
|
*
|
|
* Copyright 2018 Google, Inc
|
|
* Written by Simon Glass <sjg@chromium.org>
|
|
*/
|
|
|
|
#include <config.h>
|
|
|
|
.section .text.start
|
|
.code32
|
|
.globl _start
|
|
.type _start, @function
|
|
_start:
|
|
/* Set up memory using the existing stack */
|
|
mov %esp, %eax
|
|
call board_init_f_alloc_reserve
|
|
mov %eax, %esp
|
|
|
|
call board_init_f_init_reserve
|
|
|
|
xorl %eax, %eax
|
|
call board_init_f
|
|
call board_init_f_r
|
|
|
|
/* Should not return here */
|
|
jmp .
|
|
|
|
.globl board_init_f_r_trampoline
|
|
.type board_init_f_r_trampoline, @function
|
|
board_init_f_r_trampoline:
|
|
/*
|
|
* TPL has been executed: SDRAM has been initialised, BSS has been
|
|
* cleared.
|
|
*
|
|
* %eax = Address of top of new stack
|
|
*/
|
|
|
|
/* Stack grows down from top of SDRAM */
|
|
movl %eax, %esp
|
|
|
|
/* Re-enter SPL by calling board_init_f_r() */
|
|
call board_init_f_r
|
|
|
|
die:
|
|
hlt
|
|
jmp die
|
|
hlt
|