| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* This file is part of the coreboot project. */ |
| |
| /* For starting coreboot in protected mode */ |
| |
| #include <arch/rom_segs.h> |
| #include <cpu/x86/post_code.h> |
| #include <arch/x86/gdt_init.S> |
| |
| .code32 |
| /* |
| * When we come here we are in protected mode. We expand |
| * the stack and copies the data segment from ROM to the |
| * memory. |
| * |
| * After that, we call the chipset bootstrap routine that |
| * does what is left of the chipset initialization. |
| * |
| * NOTE aligned to 4 so that we are sure that the prefetch |
| * cache will be reloaded. |
| * |
| * In the bootblock there is already a ljmp to __protected_start and |
| * the reset vector jumps to symbol _start16bit in entry16.inc from |
| * the reset vectors's symbol which is _start. Therefore, don't |
| * expose the _start symbol for bootblock. |
| */ |
| .align 4 |
| #if !ENV_BOOTBLOCK |
| .globl _start |
| _start: |
| #endif |
| |
| lgdt %cs:gdtptr |
| ljmp $ROM_CODE_SEG, $__protected_start |
| |
| __protected_start: |
| /* Save the BIST value */ |
| movl %eax, %ebp |
| |
| #if !CONFIG(NO_EARLY_BOOTBLOCK_POSTCODES) |
| post_code(POST_ENTER_PROTECTED_MODE) |
| #endif |
| |
| movw $ROM_DATA_SEG, %ax |
| movw %ax, %ds |
| movw %ax, %es |
| movw %ax, %ss |
| movw %ax, %fs |
| movw %ax, %gs |
| |
| /* Restore the BIST value to %eax */ |
| movl %ebp, %eax |