| // Rom layout and bios assembler to C interface. |
| // |
| // Copyright (C) 2008-2012 Kevin O'Connor <kevin@koconnor.net> |
| // Copyright (C) 2002 MandrakeSoft S.A. |
| // |
| // This file may be distributed under the terms of the GNU LGPLv3 license. |
| |
| #include "asm-offsets.h" // BREGS_* |
| #include "config.h" // CONFIG_* |
| #include "entryfuncs.S" // ENTRY_* |
| #include "hw/rtc.h" // CMOS_RESET_CODE |
| #include "x86.h" // CR0_* |
| |
| .code16 |
| |
| |
| /**************************************************************** |
| * 16bit / 32bit call trampolines |
| ****************************************************************/ |
| |
| // Place CPU into 32bit mode from 16bit mode. |
| // %edx = return location (in 32bit mode) |
| // Clobbers: ecx, flags, segment registers, cr0, idt/gdt |
| DECLFUNC transition32 |
| .global transition32_nmi_off |
| transition32: |
| // Disable irqs (and clear direction flag) |
| cli |
| cld |
| |
| // Disable nmi |
| movl %eax, %ecx |
| movl $CMOS_RESET_CODE|NMI_DISABLE_BIT, %eax |
| outb %al, $PORT_CMOS_INDEX |
| inb $PORT_CMOS_DATA, %al |
| |
| // enable a20 |
| inb $PORT_A20, %al |
| orb $A20_ENABLE_BIT, %al |
| outb %al, $PORT_A20 |
| movl %ecx, %eax |
| |
| transition32_nmi_off: |
| // Set segment descriptors |
| lidtw %cs:pmode_IDT_info |
| lgdtw %cs:rombios32_gdt_48 |
| |
| // Enable protected mode |
| movl %cr0, %ecx |
| andl $~(CR0_PG|CR0_CD|CR0_NW), %ecx |
| orl $CR0_PE, %ecx |
| movl %ecx, %cr0 |
| |
| // start 32bit protected mode code |
| ljmpl $SEG32_MODE32_CS, $(BUILD_BIOS_ADDR + 1f) |
| |
| .code32 |
| // init data segments |
| 1: movl $SEG32_MODE32_DS, %ecx |
| movw %cx, %ds |
| movw %cx, %es |
| movw %cx, %ss |
| movw %cx, %fs |
| movw %cx, %gs |
| |
| jmpl *%edx |
| .code16 |
| |
| // Place CPU into 16bit mode from 32bit mode. |
| // %edx = return location (in 16bit mode) |
| // Clobbers: ecx, flags, segment registers, cr0, idt/gdt |
| DECLFUNC transition16 |
| .global transition16big |
| .code32 |
| transition16: |
| // Reset data segment limits |
| movl $SEG32_MODE16_DS, %ecx |
| movw %cx, %ds |
| movw %cx, %es |
| movw %cx, %ss |
| movw %cx, %fs |
| movw %cx, %gs |
| |
| // Jump to 16bit mode |
| ljmpw $SEG32_MODE16_CS, $1f |
| |
| transition16big: |
| movl $SEG32_MODE16BIG_DS, %ecx |
| movw %cx, %ds |
| movw %cx, %es |
| movw %cx, %ss |
| movw %cx, %fs |
| movw %cx, %gs |
| |
| ljmpw $SEG32_MODE16BIG_CS, $1f |
| |
| .code16 |
| // Disable protected mode |
| 1: movl %cr0, %ecx |
| andl $~CR0_PE, %ecx |
| movl %ecx, %cr0 |
| |
| // far jump to flush CPU queue after transition to real mode |
| ljmpw $SEG_BIOS, $2f |
| |
| // restore IDT to normal real-mode defaults |
| 2: lidtw %cs:rmode_IDT_info |
| |
| // Clear segment registers |
| xorw %cx, %cx |
| movw %cx, %fs |
| movw %cx, %gs |
| movw %cx, %es |
| movw %cx, %ds |
| movw %cx, %ss // Assume stack is in segment 0 |
| |
| jmpl *%edx |
| |
| |
| /**************************************************************** |
| * External calling trampolines |
| ****************************************************************/ |
| |
| // Far call a 16bit function from 16bit mode with a specified cpu register state |
| // %eax = address of struct bregs, %edx = segment of struct bregs |
| // Clobbers: %e[bc]x, %e[ds]i, flags |
| DECLFUNC __farcall16 |
| __farcall16: |
| // Save %edx/%eax, %ebp |
| pushl %ebp |
| pushl %eax |
| pushl %edx |
| |
| // Setup for iretw call |
| movl %edx, %ds |
| pushw %cs |
| pushw $1f // return point |
| pushw BREGS_flags(%eax) // flags |
| pushl BREGS_code(%eax) // CS:IP |
| |
| // Load calling registers and invoke call |
| RESTOREBREGS_DSEAX |
| iretw // XXX - just do a lcalll |
| 1: |
| // Store flags, es, eax |
| pushfw |
| cli |
| cld |
| pushw %ds |
| pushl %eax |
| movw 0x08(%esp), %ds |
| movl 0x0c(%esp), %eax |
| SAVEBREGS_POP_DSEAX |
| popw BREGS_flags(%eax) |
| movw %ss, %cx |
| movw %cx, %ds // Restore %ds == %ss |
| |
| // Remove %edx/%eax, restore %ebp |
| popl %edx |
| popl %eax |
| popl %ebp |
| |
| retl |
| |
| // IRQ trampolines |
| .macro IRQ_TRAMPOLINE num |
| DECLFUNC irq_trampoline_0x\num |
| irq_trampoline_0x\num : |
| int $0x\num |
| lretw |
| .endm |
| |
| IRQ_TRAMPOLINE 02 |
| IRQ_TRAMPOLINE 05 |
| IRQ_TRAMPOLINE 10 |
| IRQ_TRAMPOLINE 13 |
| IRQ_TRAMPOLINE 15 |
| IRQ_TRAMPOLINE 16 |
| IRQ_TRAMPOLINE 18 |
| IRQ_TRAMPOLINE 19 |
| IRQ_TRAMPOLINE 1b |
| IRQ_TRAMPOLINE 1c |
| IRQ_TRAMPOLINE 4a |
| |
| |
| /**************************************************************** |
| * Misc. entry points. |
| ****************************************************************/ |
| |
| // Entry point for QEMU smi interrupts. |
| DECLFUNC entry_smi |
| entry_smi: |
| // Transition to 32bit mode. |
| movl $1f + BUILD_BIOS_ADDR, %edx |
| jmp transition32_nmi_off |
| .code32 |
| 1: movl $BUILD_SMM_ADDR + 0x8000, %esp |
| calll _cfunc32flat_handle_smi - BUILD_BIOS_ADDR |
| rsm |
| .code16 |
| |
| // Entry point for QEMU smp sipi interrupts. |
| DECLFUNC entry_smp |
| entry_smp: |
| // Transition to 32bit mode. |
| cli |
| cld |
| movl $2f + BUILD_BIOS_ADDR, %edx |
| jmp transition32_nmi_off |
| .code32 |
| // Acquire lock and take ownership of shared stack |
| 1: rep ; nop |
| 2: lock btsl $0, SMPLock |
| jc 1b |
| movl SMPStack, %esp |
| // Call handle_smp |
| calll _cfunc32flat_handle_smp - BUILD_BIOS_ADDR |
| // Release lock and halt processor. |
| movl $0, SMPLock |
| 3: hlt |
| jmp 3b |
| .code16 |
| |
| // Resume (and reboot) entry point - called from entry_post |
| DECLFUNC entry_resume |
| entry_resume: |
| // Disable interrupts |
| cli |
| cld |
| // Use the ExtraStack in low mem. |
| movl $_zonelow_seg, %eax |
| movw %ax, %ds |
| movw %ax, %ss |
| movl $ExtraStack + BUILD_EXTRA_STACK_SIZE, %esp |
| // Call handler. |
| jmp handle_resume |
| |
| // PMM entry point |
| DECLFUNC entry_pmm |
| entry_pmm: |
| pushl %esp // Backup %esp, then clear high bits |
| movzwl %sp, %esp |
| pushfl // Save registers clobbered by C code |
| cli |
| cld |
| PUSHBREGS |
| movl %ss, %ecx // Move %ss to %ds |
| movw %cx, %ds |
| shll $4, %ecx |
| movl $_cfunc32flat_handle_pmm, %eax // Setup: call32(handle_pmm, args, -1) |
| leal PUSHBREGS_size+12(%esp, %ecx), %edx // %edx points to start of args |
| movl $-1, %ecx |
| calll __call32 |
| movw %ax, BREGS_eax(%esp) // Modify %ax:%dx to return %eax |
| shrl $16, %eax |
| movw %ax, BREGS_edx(%esp) |
| POPBREGS |
| popfl |
| popl %esp |
| lretw |
| |
| // PnP entry points |
| DECLFUNC entry_pnp_real |
| .global entry_pnp_prot |
| entry_pnp_prot: |
| pushl %esp |
| jmp 1f |
| entry_pnp_real: |
| pushl %esp // Backup %esp, then clear high bits |
| movzwl %sp, %esp |
| 1: |
| pushfl // Save registers clobbered by C code |
| cli |
| cld |
| PUSHBREGS |
| movw %ss, %cx // Move %ss to %ds |
| movw %cx, %ds |
| leal PUSHBREGS_size+12(%esp), %eax // %eax points to start of u16 args |
| calll handle_pnp |
| movw %ax, BREGS_eax(%esp) // Modify %eax to return %ax |
| POPBREGS |
| popfl |
| popl %esp |
| lretw |
| |
| // APM entry points |
| DECLFUNC entry_apm16 |
| entry_apm16: |
| pushfw // save flags |
| pushl %eax // dummy |
| ENTRY_ARG handle_apm |
| addw $4, %sp // pop dummy |
| popfw // restore flags |
| lretw |
| |
| DECLFUNC entry_apm32 |
| .code32 |
| entry_apm32: |
| pushfl |
| pushl %gs |
| pushl %cs // Move second descriptor after %cs to %gs |
| addl $16, (%esp) |
| popl %gs |
| ENTRY_ARG_ESP _cfunc32seg_handle_apm |
| popl %gs |
| popfl |
| lretl |
| .code16 |
| |
| // PCI-BIOS entry points |
| DECLFUNC entry_pcibios32 |
| .code32 |
| entry_pcibios32: |
| pushfl |
| pushl %gs // Backup %gs and set %gs=%ds |
| pushl %ds |
| popl %gs |
| ENTRY_ARG_ESP _cfunc32seg_handle_pcibios |
| popl %gs |
| popfl |
| lretl |
| .code16 |
| |
| DECLFUNC entry_pcibios16 |
| entry_pcibios16: |
| ENTRY_ARG handle_pcibios |
| iretw |
| |
| // int 1589 entry point |
| DECLFUNC entry_1589 |
| entry_1589: |
| ENTRY_ARG handle_1589 |
| iretw |
| |
| // BIOS32 support |
| DECLFUNC entry_bios32 |
| .code32 |
| entry_bios32: |
| pushfl |
| #if CONFIG_PCIBIOS |
| // Check for PCI-BIOS request |
| cmpl $0x49435024, %eax // $PCI |
| jne 1f |
| movl $BUILD_BIOS_ADDR, %ebx |
| movl $BUILD_BIOS_SIZE, %ecx |
| movl $entry_pcibios32, %edx |
| xorb %al, %al |
| jmp 2f |
| #endif |
| // Unknown request |
| 1: movb $0x80, %al |
| // Return to caller |
| 2: popfl |
| lretl |
| .code16 |
| |
| // 32bit elf entry point |
| DECLFUNC entry_elf |
| .code32 |
| entry_elf: |
| cli |
| cld |
| movl %eax, entry_elf_eax |
| movl %ebx, entry_elf_ebx |
| lidtl (BUILD_BIOS_ADDR + pmode_IDT_info) |
| lgdtl (BUILD_BIOS_ADDR + rombios32_gdt_48) |
| movl $SEG32_MODE32_DS, %eax |
| movw %ax, %ds |
| movw %ax, %es |
| movw %ax, %fs |
| movw %ax, %gs |
| movw %ax, %ss |
| movl $BUILD_STACK_ADDR, %esp |
| ljmpl $SEG32_MODE32_CS, $_cfunc32flat_handle_post |
| .code16 |
| |
| // UEFI Compatibility Support Module (CSM) entry point |
| DECLFUNC entry_csm |
| entry_csm: |
| // Backup register state |
| pushfw |
| cli |
| cld |
| pushl %eax // dummy |
| PUSHBREGS |
| |
| // Backup stack location and convert to a "flat pointer" |
| movl %ss, %eax |
| movw %ax, BREGS_code+2(%esp) // Store %ss in bregs->code.seg |
| shll $4, %eax |
| addl %esp, %eax |
| |
| // Change to BUILD_STACK_ADDR stack and call handle_csm(bregs) |
| ENTRY_INTO32 _cfunc32flat_handle_csm |
| |
| DECLFUNC __csm_return |
| .code32 |
| __csm_return: |
| movl $1f, %edx |
| jmp transition16big |
| .code16 |
| |
| // Switch back to original stack |
| 1: movzwl BREGS_code+2(%eax), %edx |
| movl %edx, %ecx |
| shll $4, %ecx |
| subl %ecx, %eax |
| movl %edx, %ss |
| movl %eax, %esp |
| |
| // Restore register state and return. |
| POPBREGS |
| addw $4, %sp // pop dummy |
| popfw |
| lretw |
| |
| // Serial console "hooked vga" entry point |
| DECLFUNC entry_sercon |
| entry_sercon: |
| // Setup for chain loading to real vga handler |
| pushfw |
| pushl %cs:sercon_real_vga_handler |
| |
| // Set %ds to varlow segment |
| cli |
| cld |
| pushw %ds |
| pushl %eax |
| movl $_zonelow_seg, %eax |
| movl %eax, %ds |
| |
| // Test if the sercon handler can be called |
| movl %esp, %eax // Test for broken x86emu |
| pushl $1f |
| retl |
| 1: cmpl %esp, %eax |
| jne 4f |
| cmpb $0, sercon_enable // Test that sercon is enabled |
| je 3f |
| |
| // call handle_sercon |
| popl %eax |
| popw %ds |
| 2: pushl $handle_sercon |
| #if CONFIG_ENTRY_EXTRASTACK |
| jmp irqentry_arg_extrastack |
| #else |
| jmp irqentry_arg |
| #endif |
| |
| // sercon disabled - check for legacy text modeset and otherwise exit |
| 3: popl %eax |
| popw %ds |
| cmpw $0x0007, %ax |
| jle 2b |
| iretw |
| |
| // Running on broken x86emu - restore stack and exit |
| 4: movl %eax, %esp |
| popl %eax |
| popw %ds |
| iretw |
| |
| |
| /**************************************************************** |
| * Interrupt entry points |
| ****************************************************************/ |
| |
| // Main entry point for hardware interrupts handled on extra stack |
| DECLFUNC irqentry_extrastack |
| irqentry_extrastack: |
| cli |
| cld |
| pushw %ds // Set %ds:%eax to space on ExtraStack |
| pushl %eax |
| movl $_zonelow_seg, %eax |
| movl %eax, %ds |
| movl StackPos, %eax |
| subl $PUSHBREGS_size+8, %eax |
| SAVEBREGS_POP_DSEAX |
| popl %ecx |
| movl %esp, PUSHBREGS_size(%eax) |
| movw %ss, PUSHBREGS_size+4(%eax) |
| |
| movw %ds, %dx // Setup %ss/%esp and call function |
| movw %dx, %ss |
| movl %eax, %esp |
| calll *%ecx |
| |
| movl %esp, %eax // Restore registers and return |
| movw PUSHBREGS_size+4(%eax), %ss |
| movl PUSHBREGS_size(%eax), %esp |
| RESTOREBREGS_DSEAX |
| iretw |
| |
| // Main entry point for software interrupts handled on extra stack |
| DECLFUNC irqentry_arg_extrastack |
| irqentry_arg_extrastack: |
| cli |
| cld |
| pushw %ds // Set %ds:%eax to space on ExtraStack |
| pushl %eax |
| movl $_zonelow_seg, %eax |
| movl %eax, %ds |
| movl StackPos, %eax |
| subl $PUSHBREGS_size+16, %eax |
| SAVEBREGS_POP_DSEAX // Save registers on extra stack |
| popl %ecx |
| movl %esp, PUSHBREGS_size+8(%eax) |
| movw %ss, PUSHBREGS_size+12(%eax) |
| popl BREGS_code(%eax) |
| popw BREGS_flags(%eax) |
| |
| movw %ds, %dx // Setup %ss/%esp and call function |
| movw %dx, %ss |
| movl %eax, %esp |
| calll *%ecx |
| |
| movl %esp, %eax // Restore registers and return |
| movw PUSHBREGS_size+12(%eax), %ss |
| movl PUSHBREGS_size+8(%eax), %esp |
| popl %edx |
| popw %dx |
| pushw BREGS_flags(%eax) |
| pushl BREGS_code(%eax) |
| RESTOREBREGS_DSEAX |
| iretw |
| |
| // Main entry point for software interrupts (using caller's stack) |
| DECLFUNC irqentry_arg |
| irqentry_arg: |
| ENTRY_ARG_ST |
| iretw |
| |
| // Helper macros for hardware interrupt declaration |
| .macro IRQ_ENTRY num |
| .global entry_\num |
| entry_\num : |
| pushl $ handle_\num |
| jmp irqentry_extrastack |
| .endm |
| |
| .macro DECL_IRQ_ENTRY num |
| DECLFUNC entry_\num |
| IRQ_ENTRY \num |
| .endm |
| |
| // Helper macros for software interrupt declaration |
| .macro IRQ_ENTRY_ARG num |
| .global entry_\num |
| entry_\num : |
| pushl $ handle_\num |
| #if CONFIG_ENTRY_EXTRASTACK |
| jmp irqentry_arg_extrastack |
| #else |
| jmp irqentry_arg |
| #endif |
| .endm |
| |
| .macro DECL_IRQ_ENTRY_ARG num |
| DECLFUNC entry_\num |
| IRQ_ENTRY_ARG \num |
| .endm |
| |
| // Various entry points (that don't require a fixed location). |
| DECL_IRQ_ENTRY_ARG 13 |
| DECL_IRQ_ENTRY 76 |
| DECL_IRQ_ENTRY 70 |
| DECL_IRQ_ENTRY 74 |
| DECL_IRQ_ENTRY 75 |
| DECL_IRQ_ENTRY hwpic1 |
| DECL_IRQ_ENTRY hwpic2 |
| |
| // int 18/19 are special - they reset stack and call into 32bit mode. |
| DECLFUNC entry_19 |
| entry_19: |
| ENTRY_INTO32 _cfunc32flat_handle_19 |
| |
| DECLFUNC entry_18 |
| entry_18: |
| ENTRY_INTO32 _cfunc32flat_handle_18 |
| |
| |
| /**************************************************************** |
| * Fixed position entry points |
| ****************************************************************/ |
| |
| // Specify a location in the fixed part of bios area. |
| .macro ORG addr |
| .section .fixedaddr.\addr |
| .endm |
| |
| ORG 0xe05b |
| entry_post: |
| cmpl $0, %cs:HaveRunPost // Check for resume/reboot |
| jnz entry_resume |
| ENTRY_INTO32 _cfunc32flat_handle_post // Normal entry point |
| |
| ORG 0xe2c3 |
| .global entry_02 |
| entry_02: |
| ENTRY handle_02 // NMI handler does not switch onto extra stack |
| iretw |
| |
| ORG 0xe3fe |
| .global entry_13_official |
| entry_13_official: |
| jmp entry_13 |
| |
| // 0xe401 - OldFDPT in misc.c |
| |
| ORG 0xe6f2 |
| .global entry_19_official |
| entry_19_official: |
| jmp entry_19 |
| |
| // 0xe6f5 - BIOS_CONFIG_TABLE in misc.c |
| |
| // 0xe729 - BaudTable in misc.c |
| |
| ORG 0xe739 |
| IRQ_ENTRY_ARG 14 |
| |
| ORG 0xe82e |
| IRQ_ENTRY_ARG 16 |
| |
| ORG 0xe987 |
| IRQ_ENTRY 09 |
| |
| ORG 0xec59 |
| IRQ_ENTRY_ARG 40 |
| |
| ORG 0xef57 |
| IRQ_ENTRY 0e |
| |
| // 0xefc7 - diskette_param_table in misc.c |
| |
| ORG 0xefd2 |
| IRQ_ENTRY_ARG 17 |
| |
| ORG 0xf045 |
| entry_10_0x0f: |
| // XXX - INT 10 Functions 0-Fh Entry Point |
| iretw |
| |
| ORG 0xf065 |
| entry_10: |
| iretw |
| |
| // 0xf0a4 - VideoParams in misc.c |
| |
| ORG 0xf841 |
| IRQ_ENTRY_ARG 12 |
| |
| ORG 0xf84d |
| IRQ_ENTRY_ARG 11 |
| |
| ORG 0xf859 |
| .global entry_15_official |
| entry_15_official: |
| cmpb $0x89, %ah |
| je entry_1589 // 1589 calls return in protected mode |
| IRQ_ENTRY_ARG 15 |
| |
| // 0xfa6e - vgafont8 in font.c |
| |
| ORG 0xfe6e |
| .global entry_1a_official |
| entry_1a_official: |
| cmpb $0xb1, %ah |
| je entry_pcibios16 // PCIBIOS calls can be in protected mode |
| IRQ_ENTRY_ARG 1a |
| |
| ORG 0xfea5 |
| IRQ_ENTRY 08 |
| |
| // 0xfef3 - InitVectors in misc.c |
| |
| ORG 0xff53 |
| .global entry_iret_official |
| entry_iret_official: |
| iretw |
| |
| ORG 0xff54 |
| IRQ_ENTRY_ARG 05 |
| |
| ORG 0xfff0 // Power-up Entry Point |
| .global reset_vector |
| reset_vector: |
| ljmpw $SEG_BIOS, $entry_post |
| |
| // 0xfff5 - BiosDate in misc.c |
| |
| // 0xfffe - BiosModelId in misc.c |
| |
| // 0xffff - BiosChecksum in misc.c |
| |
| .end |
