diff options
Diffstat (limited to 'arch/x86/cpu/cpu.c')
| -rw-r--r-- | arch/x86/cpu/cpu.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c index bb4a110..b6c585a 100644 --- a/arch/x86/cpu/cpu.c +++ b/arch/x86/cpu/cpu.c @@ -164,6 +164,26 @@ void setup_gdt(gd_t *id, u64 *gdt_addr) load_fs(X86_GDT_ENTRY_32BIT_FS); } +#ifdef CONFIG_HAVE_FSP +/* + * Setup FSP execution environment GDT + * + * Per Intel FSP external architecture specification, before calling any FSP + * APIs, we need make sure the system is in flat 32-bit mode and both the code + * and data selectors should have full 4GB access range. Here we reuse the one + * we used in arch/x86/cpu/start16.S, and reload the segement registers. + */ +void setup_fsp_gdt(void) +{ + load_gdt((const u64 *)(gdt_rom + CONFIG_RESET_SEG_START), 4); + load_ds(X86_GDT_ENTRY_32BIT_DS); + load_ss(X86_GDT_ENTRY_32BIT_DS); + load_es(X86_GDT_ENTRY_32BIT_DS); + load_fs(X86_GDT_ENTRY_32BIT_DS); + load_gs(X86_GDT_ENTRY_32BIT_DS); +} +#endif + int __weak x86_cleanup_before_linux(void) { #ifdef CONFIG_BOOTSTAGE_STASH |