Commit 497a9810 authored by Simon Glass's avatar Simon Glass
Browse files

x86: Add support for starting from SPL/TPL



When a previous phase of U-Boot has run we need to adjust the init of
subsequent states to avoid messing up the CPU state.

Add a new version of the start logic for SPL, when it boots from TPL
(start_from tpl.c) and a new version for U-Boot when it boots from SPL.

Series-changes: 2
- Add xorl to TPL code also
- Update comments in start_from_tpl to correctly explain SPL state
Signed-off-by: Simon Glass's avatarSimon Glass <sjg@chromium.org>
parent 774fdd5b
......@@ -4,9 +4,21 @@ ifeq ($(CONFIG_EFI_APP),)
ifdef CONFIG_$(SPL_)X86_64
head-y := arch/x86/cpu/start64.o
else
ifeq ($(CONFIG_$(SPL_TPL_)X86_16BIT_INIT),y)
head-y := arch/x86/cpu/start.o
else
ifndef CONFIG_SPL
head-y := arch/x86/cpu/start.o
else
ifdef CONFIG_SPL_BUILD
head-y = arch/x86/cpu/start_from_tpl.o
else
head-y = arch/x86/cpu/start_from_spl.o
endif
endif
endif
endif
endif # EFI
head-$(CONFIG_$(SPL_)X86_16BIT_INIT) += arch/x86/cpu/start16.o
head-$(CONFIG_$(SPL_)X86_16BIT_INIT) += arch/x86/cpu/resetvec.o
......
......@@ -9,9 +9,22 @@
ifeq ($(CONFIG_$(SPL_)X86_64),y)
extra-y = start64.o
else
ifeq ($(CONFIG_$(SPL_TPL_)X86_16BIT_INIT),y)
extra-y = start.o
else
ifndef CONFIG_SPL
extra-y = start.o
else
ifdef CONFIG_SPL_BUILD
extra-y = start_from_tpl.o
else
extra-y = start_from_spl.o
endif
extra-$(CONFIG_$(SPL_)X86_16BIT_INIT) += resetvec.o start16.o
endif
endif
endif
extra-$(CONFIG_$(SPL_TPL_)X86_16BIT_INIT) += resetvec.o start16.o
obj-y += cpu.o cpu_x86.o
......
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* 32-bit x86 Startup Code when running from SPL
*
* 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 */
movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %eax
#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %eax
#endif
/*
* We don't subject CONFIG_DCACHE_RAM_MRC_VAR_SIZE since memory is
* already set up. This has the happy side-effect of putting gd in a
* new place separate from SPL, so the memset() in
* board_init_f_init_reserve() does not cause any problems (otherwise
* it would zero out the gd and crash)
*/
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:
/*
* SPL has been executed and SDRAM has been initialised, U-Boot code
* has been copied into RAM, BSS has been cleared and relocation
* adjustments have been made. It is now time to jump into the in-RAM
* copy of U-Boot
*
* %eax = Address of top of new stack
*/
/* Stack grows down from top of SDRAM */
movl %eax, %esp
/* Re-enter U-Boot by calling board_init_f_r() */
call board_init_f_r
die:
hlt
jmp die
hlt
.align 4
_dt_ucode_base_size:
/* These next two fields are filled in by binman */
.globl ucode_base
ucode_base: /* Declared in microcode.h */
.long 0 /* microcode base */
.globl ucode_size
ucode_size: /* Declared in microcode.h */
.long 0 /* microcode size */
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* 32-bit x86 Startup Code when running from TPL
*
* 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
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