diff options
Diffstat (limited to 'qemu/roms/openbios/arch/x86/entry.S')
| -rw-r--r-- | qemu/roms/openbios/arch/x86/entry.S | 315 |
1 files changed, 0 insertions, 315 deletions
diff --git a/qemu/roms/openbios/arch/x86/entry.S b/qemu/roms/openbios/arch/x86/entry.S deleted file mode 100644 index 8f1e42eed..000000000 --- a/qemu/roms/openbios/arch/x86/entry.S +++ /dev/null @@ -1,315 +0,0 @@ - .globl entry, __switch_context, __exit_context, halt, init_exceptions - - .text - .align 4 - -/* - * Entry point - * We start execution from here. - * It is assumed that CPU is in 32-bit protected mode and - * all segments are 4GB and base zero (flat model). - */ -entry: - /* Save boot context and switch to our main context. - * Main context is statically defined in C. - */ - pushl %cs - call __switch_context - - /* We get here when the main context switches back to - * the boot context. - * Return to previous bootloader. - */ - ret - -/* - * Switch execution context - * This saves registers, segments, and GDT in the stack, then - * switches the stack, and restores everything from the new stack. - * This function takes no argument. New stack pointer is - * taken from global variable __context, and old stack pointer - * is also saved to __context. This way we can just jump to - * this routine to get back to the original context. - * - * Call this routine with lcall or pushl %cs; call. - */ -__switch_context: - /* Save everything in current stack */ - pushfl /* 56 */ - pushl %ds /* 52 */ - pushl %es /* 48 */ - pushl %fs /* 44 */ - pushl %gs /* 40 */ - pushal /* 8 */ - subl $8, %esp - movw %ss, (%esp) /* 0 */ - sgdt 2(%esp) /* 2 */ - -#if 0 - /* Swap %cs and %eip on the stack, so lret will work */ - movl 60(%esp), %eax - xchgl %eax, 64(%esp) - movl %eax, 60(%esp) -#endif - - /* At this point we don't know if we are on flat segment - * or relocated. So compute the address offset from %eip. - * Assuming CS.base==DS.base==SS.base. - */ - call 1f -1: popl %ebx - subl $1b, %ebx - - /* Interrupts are not allowed... */ - cli - - /* Current context pointer is our stack pointer */ - movl %esp, %esi - - /* Normalize the ctx pointer */ - subl %ebx, %esi - - /* Swap it with new value */ - xchgl %esi, __context(%ebx) - - /* Adjust new ctx pointer for current address offset */ - addl %ebx, %esi - - /* Load new %ss and %esp to temporary */ - movzwl (%esi), %edx - movl 20(%esi), %eax - - /* Load new GDT */ - lgdt 2(%esi) - - /* Load new stack segment with new GDT */ - movl %edx, %ss - - /* Set new stack pointer, but we have to adjust it because - * pushal saves %esp value before pushal, and we want the value - * after pushal. - */ - leal -32(%eax), %esp - - /* Load the rest from new stack */ - popal - popl %gs - popl %fs - popl %es - popl %ds - popfl - - /* Finally, load new %cs and %eip */ - lret - -__exit_context: - /* Get back to the original context */ - pushl %cs - call __switch_context - - /* We get here if the other context attempt to switch to this - * dead context. This should not happen. */ - -halt: - cli - hlt - jmp halt - -/* - * initialize exception handler. All exceptions end up in the same - * C function. - */ - -init_exceptions: - pushl %ebx - pushl %edi - - /* Initialize the Interrupt Descriptor table */ - leal _idt, %edi - leal vec0, %ebx - movl $(0x08 << 16), %eax /* cs selector */ - -1: movw %bx, %ax - movl %ebx, %edx - movw $0x8E00, %dx /* Interrupt gate - dpl=0, present */ - movl %eax, 0(%edi) - movl %edx, 4(%edi) - addl $6, %ebx - addl $8, %edi - cmpl $_idt_end, %edi - jne 1b - - /* Load the Interrupt descriptor table */ - lidt idtarg - - movl $0, %eax - popl %edi - popl %ebx - ret - -vec0: - pushl $0 /* error code */ - pushl $0 /* vector */ - jmp int_hand -vec1: - pushl $0 /* error code */ - pushl $1 /* vector */ - jmp int_hand - -vec2: - pushl $0 /* error code */ - pushl $2 /* vector */ - jmp int_hand - -vec3: - pushl $0 /* error code */ - pushl $3 /* vector */ - jmp int_hand - -vec4: - pushl $0 /* error code */ - pushl $4 /* vector */ - jmp int_hand - -vec5: - pushl $0 /* error code */ - pushl $5 /* vector */ - jmp int_hand - -vec6: - pushl $0 /* error code */ - pushl $6 /* vector */ - jmp int_hand -vec7: - pushl $0 /* error code */ - pushl $7 /* vector */ - jmp int_hand - -vec8: - /* error code */ - pushl $8 /* vector */ - jmp int_hand - .word 0x9090 - -vec9: - pushl $0 /* error code */ - pushl $9 /* vector */ - jmp int_hand - -vec10: - /* error code */ - pushl $10 /* vector */ - jmp int_hand - .word 0x9090 - -vec11: - /* error code */ - pushl $11 /* vector */ - jmp int_hand - .word 0x9090 - -vec12: - /* error code */ - pushl $12 /* vector */ - jmp int_hand - .word 0x9090 - -vec13: - /* error code */ - pushl $13 /* vector */ - jmp int_hand - .word 0x9090 - -vec14: - /* error code */ - pushl $14 /* vector */ - jmp int_hand - .word 0x9090 - -vec15: - pushl $0 /* error code */ - pushl $15 /* vector */ - jmp int_hand - -vec16: - pushl $0 /* error code */ - pushl $16 /* vector */ - jmp int_hand - -vec17: - /* error code */ - pushl $17 /* vector */ - jmp int_hand - .word 0x9090 - -vec18: - pushl $0 /* error code */ - pushl $18 /* vector */ - jmp int_hand - -vec19: - pushl $0 /* error code */ - pushl $19 /* vector */ - jmp int_hand - -__divide_error: - pushl $0 /* error code */ - pushl $20 /* vector */ - jmp int_hand - .global __divide_error - -int_hand: - /* At this point on the stack there is: - * 0(%esp) vector - * 4(%esp) error code - * 8(%esp) eip - * 12(%esp) cs - * 16(%esp) eflags - */ - pushl %edi - pushl %esi - pushl %ebp - /* Original stack pointer */ - leal 32(%esp), %ebp - pushl %ebp - pushl %ebx - pushl %edx - pushl %ecx - pushl %eax - - pushl %esp /* Pointer to structure on the stack */ - - call x86_exception - pop %eax /* Drop the pointer */ - - popl %eax - popl %ecx - popl %edx - popl %ebx - popl %ebp /* Ignore saved %esp value */ - popl %ebp - popl %esi - popl %edi - - addl $8, %esp /* pop of the vector and error code */ - - iret - -idtarg: - .word _idt_end - _idt - 1 /* limit */ - .long _idt - .word 0 -_idt: - .fill 20, 8, 0 # idt is unitiailzed -_idt_end: - - .globl arch_nvram_size, arch_nvram_get, arch_nvram_put -arch_nvram_size: - xor %eax, %eax - ret - -arch_nvram_get: - ret - -arch_nvram_put: - ret |