// Rom layout and bios assembler to C interface.
//
-// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2008,2009 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 "config.h" // CONFIG_*
-#include "ioport.h" // PORT_A20
-#include "bregs.h" // CR0_*
-#include "cmos.h" // CMOS_RESET_CODE
-#include "../out/asm-offsets.h" // BREGS_*
-
/****************************************************************
* Include of 16bit C code
****************************************************************/
.code16gcc
-.include "out/ccode.16.s"
-
-
-/****************************************************************
- * Entry macros
- ****************************************************************/
-
- // Call a C function - this does the minimal work necessary to
- // call into C. It sets up %ds, backs up %es, and backs up
- // those registers that are call clobbered by the C compiler.
- .macro ENTRY cfunc
- cli // In case something far-calls instead of using "int"
- cld
- pushl %eax // Save registers clobbered by C code
- pushl %ecx
- pushl %edx
- pushw %es
- pushw %ds
- movw %ss, %ax // Move %ss to %ds
- movw %ax, %ds
- pushl %esp // Backup %esp, then clear high bits
- movzwl %sp, %esp
- calll \cfunc
- popl %esp // Restore %esp (including high bits)
- popw %ds // Restore registers saved above
- popw %es
- popl %edx
- popl %ecx
- popl %eax
- .endm
-
- // Call a C function with current register list as an
- // argument. This backs up the registers and sets %eax
- // to point to the backup. On return, the registers are
- // restored from the structure.
- .macro ENTRY_ARG cfunc
- cli
- cld
- pushl %eax // Save registers (matches struct bregs)
- pushl %ecx
- pushl %edx
- pushl %ebx
- pushl %esi
- pushl %edi
- pushw %es
- pushw %ds
- movw %ss, %ax // Move %ss to %ds
- movw %ax, %ds
- movl %esp, %ebx // Backup %esp, then zero high bits
- movzwl %sp, %esp
- movl %esp, %eax // First arg is pointer to struct bregs
- calll \cfunc
- movl %ebx, %esp // Restore %esp (including high bits)
- popw %ds // Restore registers (from struct bregs)
- popw %es
- popl %edi
- popl %esi
- popl %ebx
- popl %edx
- popl %ecx
- popl %eax
- .endm
-
- // As above, but don't mangle %esp
- .macro ENTRY_ARG_ESP cfunc
- cli
- cld
- pushl %eax // Save registers (matches struct bregs)
- pushl %ecx
- pushl %edx
- pushl %ebx
- pushl %esi
- pushl %edi
- pushw %es
- pushw %ds
- movw %ss, %ax // Move %ss to %ds
- movw %ax, %ds
- movl %esp, %eax // First arg is pointer to struct bregs
- calll \cfunc
- popw %ds // Restore registers (from struct bregs)
- popw %es
- popl %edi
- popl %esi
- popl %ebx
- popl %edx
- popl %ecx
- popl %eax
- .endm
-
- // Reset stack, transition to 32bit mode, and call a C function.
- // Clobbers %ax
- .macro ENTRY_INTO32 cfunc
- xorw %ax, %ax
- movw %ax, %ss
- movl $ BUILD_STACK_ADDR , %esp
- pushl $ \cfunc
- jmp transition32
- .endm
+#include "ccode.16.s"
- // Declare a function
- .macro DECLFUNC func
- .section .text.asm.\func
- .global \func
- .endm
+#include "config.h" // CONFIG_*
+#include "ioport.h" // PORT_A20
+#include "bregs.h" // CR0_*
+#include "cmos.h" // CMOS_RESET_CODE
+#include "asm-offsets.h" // BREGS_*
+#include "entryfuncs.S" // ENTRY_*
/****************************************************************
****************************************************************/
// Place CPU into 32bit mode from 16bit mode.
-// Clobbers: flags, segment registers, cr0, idt/gdt
-// Require: interrupts must be disabled
+// %edx = return location (in 32bit mode)
+// Clobbers: ecx, flags, segment registers, cr0, idt/gdt
DECLFUNC transition32
transition32:
- pushl %eax
+ movl %eax, %ecx
+
+ // Disable irqs (and clear direction flag)
+ cli
+ cld
+
+ // Disable nmi
+ movl $CMOS_RESET_CODE|NMI_DISABLE_BIT, %eax
+ outb %al, $PORT_CMOS_INDEX
+ inb $PORT_CMOS_DATA, %al
// enable a20
inb $PORT_A20, %al
lidtw %cs:pmode_IDT_info
lgdtw %cs:rombios32_gdt_48
- // Disable nmi
- movl $CMOS_RESET_CODE|NMI_DISABLE_BIT, %eax
- outb %al, $PORT_CMOS_INDEX
- inb $PORT_CMOS_DATA, %al
-
// Enable protected mode
movl %cr0, %eax
orl $CR0_PE, %eax
movw %ax, %fs
movw %ax, %gs
- popl %eax
- retl
+ movl %ecx, %eax
+ jmpl *%edx
-// Call a 16bit function from 32bit mode.
-// %eax = address of struct bregs
-// Clobbers: %e[bcd]x, %e[ds]i, flags, segment registers, idt/gdt
- DECLFUNC __call16_from32
- .global __call16big_from32
-__call16_from32:
- pushl %eax
+// 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
+transition16:
+ movl %eax, %ecx
// restore data segment limits to 0xffff
movl $SEG32_MODE16_DS, %eax
movw %ax, %fs
movw %ax, %gs
+#if CONFIG_DISABLE_A20
// disable a20
inb $PORT_A20, %al
andb $~A20_ENABLE_BIT, %al
outb %al, $PORT_A20
+#endif
// Jump to 16bit mode
ljmpw $SEG32_MODE16_CS, $1f
-__call16big_from32:
- pushl %eax
+transition16big:
+ movl %eax, %ecx
movl $SEG32_MODE16BIG_DS, %eax
movw %ax, %ds
movw %ax, %fs
movw %ax, %gs
- ljmpl $SEG32_MODE16BIG_CS, $(BUILD_BIOS_ADDR + 1f)
+ ljmpw $SEG32_MODE16BIG_CS, $1f
.code16gcc
1:
movw %ax, %ds
movw %ax, %ss // Assume stack is in segment 0
- popl %eax
-
- // Make call.
- calll __call16
-
- // Return via transition32
- jmp transition32
-
+ movl %ecx, %eax
+ jmpl *%edx
// Call a 16bit function from 16bit mode with a specified cpu register state
// %eax = address of struct bregs
pushw %cs
pushw $1f // return point
pushw BREGS_flags(%eax) // flags
- pushl BREGS_ip(%eax) // CS:IP
+ pushl BREGS_code(%eax) // CS:IP
// Load calling registers.
movl BREGS_edi(%eax), %edi
movl BREGS_esi(%eax), %esi
+ movl BREGS_ebp(%eax), %ebp
movl BREGS_ebx(%eax), %ebx
movl BREGS_edx(%eax), %edx
movl BREGS_ecx(%eax), %ecx
movw %es, BREGS_es(%eax)
movl %edi, BREGS_edi(%eax)
movl %esi, BREGS_esi(%eax)
+ movl %ebp, BREGS_ebp(%eax)
movl %ebx, BREGS_ebx(%eax)
movl %edx, BREGS_edx(%eax)
popl %eax
popl %ebp
- cli
- cld
-
retl
+// Call a 16bit function from 32bit mode.
+// %eax = address of struct bregs
+// Clobbers: %e[bcd]x, %e[ds]i, flags, segment registers, idt/gdt
+ DECLFUNC __call16_from32
+ .global __call16big_from32
+ .code32
+__call16_from32:
+ movl $1f, %edx
+ jmp transition16
+__call16big_from32:
+ movl $1f, %edx
+ jmp transition16big
+
+ // Make call.
+ .code16gcc
+1: calll __call16
+ // Return via transition32
+ movl $(2f + BUILD_BIOS_ADDR), %edx
+ jmp transition32
+ .code32
+2: retl
+
+ .code16gcc
// IRQ trampolines
.macro IRQ_TRAMPOLINE num
DECLFUNC irq_trampoline_0x\num
/****************************************************************
- * POST entry point
+ * Misc. entry points.
****************************************************************/
- DECLFUNC entry_post
-entry_post:
- // Enable cache
- movl %cr0, %eax
- andl $~(CR0_CD|CR0_NW), %eax
- movl %eax, %cr0
-
+// Resume (and reboot) entry point - called from entry_post
+ DECLFUNC entry_resume
+entry_resume:
// Disable interrupts
cli
cld
-
- // Check for restart indicator.
- movl $CMOS_RESET_CODE|NMI_DISABLE_BIT, %eax
- outb %al, $PORT_CMOS_INDEX
- inb $PORT_CMOS_DATA, %al
- cmpb $0x0, %al
- jnz 1f
-
- // Normal entry point
- ENTRY_INTO32 _code32__start
-
- // Entry point when a post call looks like a resume.
-1:
- // Save old shutdown status.
- movl %eax, %ebx
-
- // Clear shutdown status register.
- movl $CMOS_RESET_CODE|NMI_DISABLE_BIT, %eax
- outb %al, $PORT_CMOS_INDEX
- xorl %eax, %eax
- outb %al, $PORT_CMOS_DATA
-
// Use a stack in EBDA
movw $SEG_BDA, %ax
movw %ax, %ds
movw BDA_ebda_seg, %ax
- // XXX - should verify ebda_seg looks sane.
movw %ax, %ds
movw %ax, %ss
movl $EBDA_OFFSET_TOP_STACK, %esp
-
// Call handler.
- movl %ebx, %eax
jmp handle_resume
-
-/****************************************************************
- * Misc. entry points.
- ****************************************************************/
+// 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
+ pushl %eax
+ pushl %ecx
+ pushl %edx
+ pushw %es
+ pushw %ds
+ movw %ss, %cx // Move %ss to %ds
+ movw %cx, %ds
+ movl $_cfunc32flat_handle_pmm, %eax // Setup: call32(handle_pmm, args, -1)
+ leal 28(%esp), %edx // %edx points to start of args
+ movl $-1, %ecx
+ calll call32
+ movw %ax, 12(%esp) // Modify %ax:%dx to return %eax
+ shrl $16, %eax
+ movw %ax, 4(%esp)
+ popw %ds // Restore saved registers
+ popw %es
+ popl %edx
+ popl %ecx
+ popl %eax
+ popfl
+ popl %esp
+ lretw
// PnP entry points
DECLFUNC entry_pnp_real
movzwl %sp, %esp
1:
pushfl // Save registers clobbered by C code
+ cli
+ cld
pushl %eax
pushl %ecx
pushl %edx
pushw %ds
movw %ss, %cx // Move %ss to %ds
movw %cx, %ds
- lea 28(%esp), %eax // %eax points to start of u16 args
+ leal 28(%esp), %eax // %eax points to start of u16 args
calll handle_pnp
movw %ax, 12(%esp) // Modify %eax to return %ax
popw %ds
lretw
// APM entry points
- DECLFUNC apm16protected_entry
-apm16protected_entry:
+ DECLFUNC entry_apm16
+entry_apm16:
pushfw // save flags
pushl %eax // dummy
- ENTRY_ARG handle_1553
+ ENTRY_ARG handle_apm16
addw $4, %sp // pop dummy
popfw // restore flags
lretw
.code32
- DECLFUNC apm32protected_entry
-apm32protected_entry:
- pushfw
- pushw %cs // Setup for long jump to 16bit mode
- pushw $1f
- addw $8, 2(%esp)
- ljmpw *(%esp)
- .code16gcc
-1:
- ENTRY_ARG_ESP handle_1553
+ DECLFUNC entry_apm32
+entry_apm32:
+ pushfl
+ pushl %gs
+ pushl %cs // Move second descriptor after %cs to %gs
+ addl $16, (%esp)
+ popl %gs
+ ENTRY_ARG_ESP _cfunc32seg_handle_apm32
+ popl %gs
+ popfl
+ lretl
- movw $2f,(%esp) // Setup for long jump back to 32bit mode
- subw $8, 2(%esp)
- ljmpw *(%esp)
- .code32
-2:
- addl $4, %esp // pop call address
- popfw
+// PCI-BIOS 32bit entry point
+ DECLFUNC entry_pcibios32
+entry_pcibios32:
+ pushfl
+ pushl %gs // Backup %gs and set %gs=%ds
+ pushl %ds
+ popl %gs
+ ENTRY_ARG_ESP _cfunc32seg_handle_pcibios32
+ popl %gs
+ popfl
+ lretl
+
+// BIOS32 support
+ EXPORTFUNC entry_bios32
+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
// 32bit elf entry point
- DECLFUNC post32
-post32:
+ EXPORTFUNC entry_elf
+entry_elf:
cli
cld
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, $_code32__start
+ ljmpl $SEG32_MODE32_CS, $_cfunc32flat_handle_post
.code16gcc
* Interrupt entry points
****************************************************************/
+ // Main entry point for interrupts without args
+ DECLFUNC irqentry
+irqentry:
+ ENTRY_ST
+ iretw
+
+ // Main entry point for interrupts with args
+ DECLFUNC irqentryarg
+irqentryarg:
+ ENTRY_ARG_ST
+ iretw
+
// Define an entry point for an interrupt (no args passed).
.macro IRQ_ENTRY num
.global entry_\num
entry_\num :
- ENTRY handle_\num
- iretw
+ pushl $ handle_\num
+ jmp irqentry
+ .endm
+
+ .macro DECL_IRQ_ENTRY num
+ DECLFUNC entry_\num
+ IRQ_ENTRY \num
.endm
// Define an entry point for an interrupt (can read/modify args).
.macro IRQ_ENTRY_ARG num
.global entry_\num
entry_\num :
- ENTRY_ARG handle_\num
- iretw
+ pushl $ handle_\num
+ jmp irqentryarg
.endm
- // Macros that put each handler into its own section
- .macro DECL_IRQ_ENTRY num
- .section .text.asm.entry_\num
- IRQ_ENTRY \num
- .endm
.macro DECL_IRQ_ENTRY_ARG num
- .section .text.asm.entry_\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_ARG 12
- DECL_IRQ_ENTRY_ARG 11
DECL_IRQ_ENTRY 76
DECL_IRQ_ENTRY 70
DECL_IRQ_ENTRY 74
// int 18/19 are special - they reset stack and call into 32bit mode.
DECLFUNC entry_19
entry_19:
- cli
- cld
- ENTRY_INTO32 _code32_handle_19
+ ENTRY_INTO32 _cfunc32flat_handle_19
DECLFUNC entry_18
entry_18:
- cli
- cld
- ENTRY_INTO32 _code32_handle_18
+ ENTRY_INTO32 _cfunc32flat_handle_18
/****************************************************************
.endm
ORG 0xe05b
-entry_post_official:
- jmp entry_post
+entry_post:
+ cmpl $0, %cs:HaveRunPost // Check for resume/reboot
+ jnz entry_resume
+ ENTRY_INTO32 _cfunc32flat_handle_post // Normal entry point
ORG 0xe2c3
IRQ_ENTRY 02
// 0xf0a4 - VideoParams in misc.c
ORG 0xf841
- .global entry_12_official
-entry_12_official:
- jmp entry_12
+ IRQ_ENTRY_ARG 12
ORG 0xf84d
- .global entry_11_official
-entry_11_official:
- jmp entry_11
+ IRQ_ENTRY_ARG 11
ORG 0xf859
IRQ_ENTRY_ARG 15
ORG 0xfff0 // Power-up Entry Point
.global reset_vector
reset_vector:
- ljmpw $SEG_BIOS, $entry_post_official
+ ljmpw $SEG_BIOS, $entry_post
// 0xfff5 - BiosDate in misc.c