diff options
| -rw-r--r-- | i386/i386/cpuboot.S | 63 |
1 files changed, 53 insertions, 10 deletions
diff --git a/i386/i386/cpuboot.S b/i386/i386/cpuboot.S index f93e0387..76ed907d 100644 --- a/i386/i386/cpuboot.S +++ b/i386/i386/cpuboot.S @@ -31,15 +31,19 @@ #define BOOT_CS 0x8 #define BOOT_DS 0x10 +#define GDT_DESCR_M32 4 +#define GDT_TABLE_M32 (14*2) + .data .align 16 apboot_idt_ptr: .long 0 .align 16 +apboot_gdt_top: .word 0 apboot_gdt_descr: - .word 14*8-1 + .word (GDT_TABLE_M32 * 4) - 1 .long apboot_gdt - KERNELBASE .align 16 apboot_gdt: @@ -101,6 +105,9 @@ apboot_percpu_med: apboot_percpu_high: .byte 0 +/* Empty space for per-cpu gdt descriptor and gdt */ +.space (NCPUS-1) * (GDT_DESCR_M32 + GDT_TABLE_M32) * 4, 0x0 + .globl apboot, apbootend, gdt_descr_tmp, apboot_jmp_offset .align 16 .code16 @@ -159,28 +166,62 @@ apboot_jmp_offset: movw %ax, %gs movw %ax, %ss - /* Get CPU number */ + /* Get CPU number into ebp */ movl $1, %eax cpuid shrl $24, %ebx - movl %cs:CX(cpu_id_lut, %ebx), %ecx + movl %cs:CX(cpu_id_lut, %ebx), %ebp + + /* Copy first gdt descriptor and gdt to cpu-th area */ + movl $(GDT_DESCR_M32 + GDT_TABLE_M32), %ecx + movl $apboot_gdt_top, %esi + movl %esi, %edi + movl $((GDT_DESCR_M32 + GDT_TABLE_M32) * 4), %eax + mul %ebp + addl %eax, %edi + rep movsl /* Access per_cpu area */ - movl %ecx,%eax + movl %ebp, %eax movl $PC_SIZE,%ebx mul %ebx addl $percpu_array, %eax /* Record our cpu number */ - movl %ecx, (PERCPU_CPU_ID)(%eax) + movl %ebp, (PERCPU_CPU_ID)(%eax) /* Set up temporary percpu descriptor */ addl $(-KERNELBASE), %eax - movw %ax, apboot_percpu_low - shr $16, %eax - movb %al, apboot_percpu_med - shr $8, %ax - movb %al, apboot_percpu_high + movl %eax, %ebx + + /* Make eax hold offset to my cpus gdt */ + movl $((GDT_DESCR_M32 + GDT_TABLE_M32) * 4), %eax + mul %ebp + + /* Patch only our own copy of gdt */ + movl $apboot_percpu_low, %ecx + addl %eax, %ecx + movw %bx, (%ecx) + shr $16, %ebx + addl $2, %ecx + movb %bl, (%ecx) + shr $8, %bx + addl $3, %ecx + movb %bl, (%ecx) + + /* Patch only our own copy of gdt descriptor */ + movl $apboot_gdt_descr, %ecx + addl %eax, %ecx + movl %ecx, %edx + addl $2, %edx + movl (%edx), %ebx + addl %eax, %ebx + movl %ebx, (%edx) + + /* Reload our copy of gdt */ + lgdtl (%ecx) + ljmpl $KERNEL_CS, $2f +2: movw $PERCPU_DS, %ax movw %ax, %gs @@ -213,8 +254,10 @@ apboot_jmp_offset: /* Finish the cpu configuration */ call EXT(cpu_ap_main) +3: /* NOT REACHED */ hlt + jmp 3b .align 16 .word 0 |