blob: 86dbba4668ef957510136b9922fc072c74611cdc [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* Copyright 2016 Google Inc.
* Copyright (C) 2016 Intel Corp.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <rules.h>
/*
*Take the path where CAR_GLOBAL variables just need to be cleared when
* verstage runs directly after bootblock.
*/
#define ROMSTAGE_AFTER_VERSTAGE \
(IS_ENABLED(CONFIG_SEPARATE_VERSTAGE) && \
IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK) && ENV_ROMSTAGE)
#if IS_ENABLED(CONFIG_C_ENVIRONMENT_BOOTBLOCK) || ROMSTAGE_AFTER_VERSTAGE
/*
* This path is for stages that are post bootblock when employing
* CONFIG_C_ENVIRONMENT_BOOTBLOCK or any intermediate stage succeeding
* the first stage to initialize protected mode. There's no need to re-load
* the gdt, etc as all those settings are cached within the processor. In
* order to continue with C code execution one needs to set stack pointer and
* clear CAR_GLOBAL variables that are stage specific.
*/
.section ".text._start", "ax", @progbits
.global _start
_start:
/* _car_stack_end symbol is only valid when bootblock does CAR setup. */
#if IS_ENABLED(CONFIG_C_ENVIRONMENT_BOOTBLOCK)
/* reset stack pointer to CAR stack */
mov $_car_stack_end, %esp
#endif
/* clear CAR_GLOBAL area as it is not shared */
cld
xor %eax, %eax
movl $(_car_global_end), %ecx
movl $(_car_global_start), %edi
sub %edi, %ecx
rep stosl
jmp car_stage_entry
/* This is here for linking purposes. */
.weak car_stage_entry
car_stage_entry:
1:
jmp 1b
#else
/* This file assembles the start of the romstage program by the order of the
* includes. Thus, it's extremely important that one pays very careful
* attention to the order of the includes. */
#include <arch/x86/prologue.inc>
#include <cpu/x86/32bit/entry32.inc>
#include <cpu/x86/fpu_enable.inc>
#if IS_ENABLED(CONFIG_SSE)
#include <cpu/x86/sse_enable.inc>
#endif
/*
* The assembly.inc is generated based on the requirements of the mainboard.
* For example, for ROMCC boards the MAINBOARDDIR/romstage.c would be
* processed by ROMCC and added. In non-ROMCC boards the chipsets'
* cache-as-ram setup files would be here.
*/
#include <generated/assembly.inc>
#endif