diff options
Diffstat (limited to 'arch/x86/cpu/cpu.c')
| -rw-r--r-- | arch/x86/cpu/cpu.c | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c index 8102fb9..8c3b92c 100644 --- a/arch/x86/cpu/cpu.c +++ b/arch/x86/cpu/cpu.c @@ -90,6 +90,37 @@ static void load_gdt(const u64 *boot_gdt, u16 num_entries) asm volatile("lgdtl %0\n" : : "m" (gdt)); } +void init_gd(gd_t *id, u64 *gdt_addr) +{ + id->gd_addr = (ulong)id; + setup_gdt(id, gdt_addr); +} + +void setup_gdt(gd_t *id, u64 *gdt_addr) +{ + /* CS: code, read/execute, 4 GB, base 0 */ + gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff); + + /* DS: data, read/write, 4 GB, base 0 */ + gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff); + + /* FS: data, read/write, 4 GB, base (Global Data Pointer) */ + gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, (ulong)id, 0xfffff); + + /* 16-bit CS: code, read/execute, 64 kB, base 0 */ + gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff); + + /* 16-bit DS: data, read/write, 64 kB, base 0 */ + gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff); + + load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES); + load_ds(X86_GDT_ENTRY_32BIT_DS); + load_es(X86_GDT_ENTRY_32BIT_DS); + load_gs(X86_GDT_ENTRY_32BIT_DS); + load_ss(X86_GDT_ENTRY_32BIT_DS); + load_fs(X86_GDT_ENTRY_32BIT_FS); +} + int x86_cpu_init_f(void) { const u32 em_rst = ~X86_CR0_EM; @@ -117,28 +148,6 @@ int x86_cpu_init_r(void) "movl %%eax, %%cr0\n" "wbinvd\n" : : "i" (nw_cd_rst) : "eax"); - /* - * There are machines which are known to not boot with the GDT - * being 8-byte unaligned. Intel recommends 16 byte alignment - */ - static const u64 boot_gdt[] __aligned(16) = { - /* CS: code, read/execute, 4 GB, base 0 */ - [X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff), - /* DS: data, read/write, 4 GB, base 0 */ - [X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff), - /* 16-bit CS: code, read/execute, 64 kB, base 0 */ - [X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff), - /* 16-bit DS: data, read/write, 64 kB, base 0 */ - [X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff), - }; - - load_gdt(boot_gdt, X86_GDT_NUM_ENTRIES); - load_ds(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); - load_ss(X86_GDT_ENTRY_32BIT_DS); - /* Initialize core interrupt and exception functionality of CPU */ cpu_init_interrupts(); return 0; |