diff options
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/x86/Makefile.inc | 1 | ||||
| -rw-r--r-- | src/arch/x86/bootblock_crt0.S | 55 |
2 files changed, 56 insertions, 0 deletions
diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc index 2942cae3fb..21084d3fd8 100644 --- a/src/arch/x86/Makefile.inc +++ b/src/arch/x86/Makefile.inc @@ -112,6 +112,7 @@ $(call src-to-obj,bootblock,$(dir)/id.S): $(obj)/build.h ifeq ($(CONFIG_C_ENVIRONMENT_BOOTBLOCK),y) +bootblock-y += bootblock_crt0.S bootblock-y += memlayout.ld ifeq ($(CONFIG_ARCH_BOOTBLOCK_X86_32),y) diff --git a/src/arch/x86/bootblock_crt0.S b/src/arch/x86/bootblock_crt0.S new file mode 100644 index 0000000000..926cda08a7 --- /dev/null +++ b/src/arch/x86/bootblock_crt0.S @@ -0,0 +1,55 @@ +/* + * This is the modern bootblock. It is used by platforms which select + * C_ENVIRONMENT_BOOTBLOCK, and it prepares the system for C environment runtime + * setup. The actual setup is done by hardware-specific code. + * + * It provides a bootflow similar to other architectures, and thus is considered + * to be the modern approach. + * + * This file is part of the coreboot project. + * + * Copyright (C) 2015 Alexandru Gagniuc <mr.nuke.me@gmail.com> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + */ + +#define CR0_MP (1 << 1) +#define CR0_EM (1 << 2) + +#define CR4_OSFXSR (1 << 9) +#define CR4_OSXMMEXCPT (1 << 10) + +/* + * Include the old code for reset vector and protected mode entry. That code has + * withstood the test of time. + */ +#include <arch/x86/prologue.inc> +#include <cpu/x86/16bit/entry16.inc> +#include <cpu/x86/16bit/reset16.inc> +#include <cpu/x86/32bit/entry32.inc> + + +bootblock_protected_mode_entry: + /* Save BIST result */ + movd %eax, %mm0 + /* Save an early timestamp */ + rdtsc + movd %eax, %mm1 + movd %edx, %mm2 + +#if !IS_ENABLED(CONFIG_SSE) +enable_sse: + mov %cr0, %eax + and $~CR0_EM, %ax /* Clear coprocessor emulation CR0.EM */ + or $CR0_MP, %ax /* Set coprocessor monitoring CR0.MP */ + mov %eax, %cr0 + mov %cr4, %eax + or $(CR4_OSFXSR | CR4_OSXMMEXCPT), %ax + mov %eax, %cr4 +#endif /* IS_ENABLED(CONFIG_SSE) */ + + /* We're done. Now it's up to platform-specific code */ + jmp bootblock_pre_c_entry |