diff options
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/x86/assembly_entry.S | 37 | ||||
| -rw-r--r-- | src/arch/x86/include/arch/cpu.h | 9 |
2 files changed, 45 insertions, 1 deletions
diff --git a/src/arch/x86/assembly_entry.S b/src/arch/x86/assembly_entry.S index 01e91b0f47..11babe1273 100644 --- a/src/arch/x86/assembly_entry.S +++ b/src/arch/x86/assembly_entry.S @@ -1,7 +1,8 @@ /* * This file is part of the coreboot project. * - * Copyright 2015 Google Inc. + * 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 @@ -13,6 +14,8 @@ * GNU General Public License for more details. */ +#if !IS_ENABLED(CONFIG_C_ENVIRONMENT_BOOTBLOCK) + /* 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. */ @@ -31,3 +34,35 @@ * cache-as-ram setup files would be here. */ #include <generated/assembly.inc> + +#else +/* + * This path is for stages that post bootblock when employing + * CONFIG_C_ENVIRONMENT_BOOTBLOCK. 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: + + /* reset stack pointer to CAR stack */ + mov $_car_stack_end, %esp + + /* 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 +#endif diff --git a/src/arch/x86/include/arch/cpu.h b/src/arch/x86/include/arch/cpu.h index 408fa15180..f50901fe73 100644 --- a/src/arch/x86/include/arch/cpu.h +++ b/src/arch/x86/include/arch/cpu.h @@ -239,4 +239,13 @@ static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms) #define asmlinkage __attribute__((regparm(0))) #define alwaysinline inline __attribute__((always_inline)) +#ifndef __ROMCC__ +/* + * When using CONFIG_C_ENVIRONMENT_BOOTBLOCK the car_stage_entry() + * is the symbol jumped to for each stage after bootblock using + * cache-as-ram. + */ +void asmlinkage car_stage_entry(void); +#endif + #endif /* ARCH_CPU_H */ |