diff options
Diffstat (limited to 'src/arch/i386/lib/c_start.S')
-rw-r--r-- | src/arch/i386/lib/c_start.S | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/arch/i386/lib/c_start.S b/src/arch/i386/lib/c_start.S new file mode 100644 index 0000000000..f5ca3388f8 --- /dev/null +++ b/src/arch/i386/lib/c_start.S @@ -0,0 +1,135 @@ +#include <arch/asm.h> +#include <arch/intel.h> +#ifdef SMP +#include <cpu/p6/apic.h> +#endif + .section ".text" + .code32 + .globl _start +_start: + cli + lgdt %cs:gdtaddr + ljmp $0x10, $1f +1: movl $0x18, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %ss + movl %eax, %fs + movl %eax, %gs + + intel_chip_post_macro(0x13) /* post 12 */ + + /** clear stack */ + leal EXT(_stack), %edi + movl $EXT(_estack), %ecx + subl %edi, %ecx + xorl %eax, %eax + rep + stosb + + /** clear bss */ + leal EXT(_bss), %edi + movl $EXT(_ebss), %ecx + subl %edi, %ecx + jz .Lnobss + xorl %eax, %eax + rep + stosb +.Lnobss: + + /* set new stack */ + movl $_estack, %esp +#ifdef SMP + /* Get the cpu id */ + movl $APIC_DEFAULT_BASE, %edi + movl APIC_ID(%edi), %eax + shrl $24, %eax + + /* Get the cpu index (MAX_CPUS on error) */ + movl $-4, %ebx +1: addl $4, %ebx + cmpl $(MAX_CPUS << 2), %ebx + je 2 + cmpl %eax, EXT(initial_apicid)(%ebx) + jne 1b +2: shrl $2, %ebx + + /* Now compute the appropriate stack */ + movl %ebx, %eax + movl $STACK_SIZE, %ebx + mull %ebx + subl %eax, %esp +#endif + + /* push the boot_complete flag */ + pushl %ebp + + /* Save the stack location */ + movl %esp, %ebp + + /* + * Now we are finished. Memory is up, data is copied and + * bss is cleared. Now we call the main routine and + * let it do the rest. + */ + intel_chip_post_macro(0xfe) /* post fe */ + + /* Resort the stack location */ + movl %ebp, %esp + + /* The boot_complete flag has already been pushed */ + call EXT(hardwaremain) + /*NOTREACHED*/ +.Lhlt: + intel_chip_post_macro(0xee) /* post fe */ + hlt + jmp .Lhlt + + + .globl gdt, gdt_end, gdt_limit + +gdt_limit = gdt_end - gdt - 1 /* compute the table limit */ +gdtaddr: + .word gdt_limit + .long gdt /* we know the offset */ + +gdt: +// selgdt 0 + .word 0x0000, 0x0000 /* dummy */ + .byte 0x00, 0x00, 0x00, 0x00 + +// selgdt 8 + .word 0x0000, 0x0000 /* dummy */ + .byte 0x00, 0x00, 0x00, 0x00 + +// selgdt 0x10 +/* flat code segment */ + .word 0xffff, 0x0000 + .byte 0x00, 0x9b, 0xcf, 0x00 + +//selgdt 0x18 +/* flat data segment */ + .word 0xffff, 0x0000 + .byte 0x00, 0x93, 0xcf, 0x00 + +//selgdt 0x20 + .word 0x0000, 0x0000 /* dummy */ + .byte 0x00, 0x00, 0x00, 0x00 + +#if defined(CONFIG_VGABIOS) && (CONFIG_VGABIOS == 1) + // from monty: + /* 0x00009a00,0000ffffULL, 20h: 16-bit 64k code at 0x00000000 */ + /* 0x00009200,0000ffffULL 28h: 16-bit 64k data at 0x00000000 */ +// selgdt 0x28 +/*16-bit 64k code at 0x00000000 */ + .word 0xffff, 0x0000 + .byte 0, 0x9a, 0, 0 + +// selgdt 0x30 +/*16-bit 64k data at 0x00000000 */ + .word 0xffff, 0x0000 + .byte 0, 0x92, 0, 0 +#endif // defined(CONFIG_VGABIOS) && (CONFIG_VGABIOS == 1) +gdt_end: + +.code32 |