Chameleon

Chameleon Commit Details

Date:2015-03-10 07:00:12 (4 years 7 months ago)
Author:ErmaC
Commit:2603
Parents: 2602
Message:Sanitize 16-bit assembly (Merge from Zenith432 branch)
Changes:
M/trunk/i386/boot2/mboot.c
M/trunk/i386/boot2/boot.c
M/trunk/i386/libsa/interrupts.c
M/trunk/i386/libsaio/table.c
M/trunk/i386/boot2/boot2.s
M/trunk/i386/util/boot1-install/boot1-install.c
M/trunk/CHANGES
M/trunk/i386/libsaio/bios.s
M/trunk/i386/libsaio/saio_internal.h
M/trunk/i386/libsaio/asm.s

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trunk/i386/libsaio/asm.s
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#include <architecture/i386/asm_help.h>
#include "memory.h"
#define data32 .byte 0x66
#define addr32 .byte 0x67
.file "asm.s"
CR0_PE_ON = 0x1
.globl _Gdtr
//.data
.section __INIT,__data// turbo - Data that must be in the first segment
.align 2, 0x90
.align 2
_Gdtr:
.word GDTLIMIT
.long vtop(_Gdt)
.section __INIT,__data// turbo - Data that must be in the first segment
// Real mode IDT
.align 2
.globl _Idtr_real
_Idtr_real:
.word 0x03ff
.long 0x00000000
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// Data area for __switch_stack.
//
.align 2
save_sp: .long STACK_OFS
save_ss: .long STACK_SEG
save_ss: .word STACK_SEG
//.text
.section __INIT,__text // turbo - This code must reside within the first segment
.section __INIT,__text,regular,pure_instructions // turbo - This code must reside within the first segment
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// real_to_prot()
//
//
LABEL(__real_to_prot)
.code16
// Interrupts are disabled in protected mode.
cli
// Load the Global Descriptor Table Register (GDTR).
addr32
data32
lgdt OFFSET16(_Gdtr)
lgdtl OFFSET16(_Gdtr)
// Enter protected mode by setting the PE bit in CR0.
mov %cr0, %eax
data32
or $CR0_PE_ON, %eax
or $CR0_PE_ON, %ax
mov %eax, %cr0
// Make intrasegment jump to flush the processor pipeline and
// reload CS register.
data32
ljmp $0x08, $xprot
ljmpl $0x08, $xprot
.code32
xprot:
// we are in USE32 mode now
// set up the protected mode segment registers : DS, SS, ES, FS, GS
mov $0x10, %eax
movw $0x10, %ax
movw %ax, %ds
movw %ax, %ss
movw %ax, %es
popl %eax
addl $CODE32_BASE, %eax
pushl %eax
jmp *%eax
ret
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// prot_to_real()
//
ljmp $0x18, $x16 // change to USE16 mode
x16:
.code16
mov %cr0, %eax // clear the PE bit of CR0
data32
and $CR0_PE_OFF, %eax
mov %eax, %cr0
// make intersegment jmp to flush the processor pipeline
// and reload CS register
data32
ljmp $CODE16_SEG, $xreal - CODE32_BASE
ljmp $CODE16_SEG, $xreal
xreal:
// we are in real mode now
// load stack segment register SS.
data32
movl $STACK16_SEG, %eax
movw $STACK16_SEG, %ax
movw %ax, %ss
// clear top 16-bits of ESP and EBP.
data32
movzwl %sp, %esp
data32
movzwl %bp, %ebp
// Modify caller's return address on the stack
// from linear address to segment offset.
data32
popl %eax
data32
movzwl %ax, %eax
data32
pushl %eax
// Reenable maskable interrupts.
sti
data32
ret
jmp *%ax
.code32
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// halt()
//
// Passes arg to the program in %eax.
//
LABEL(_startprog)
push %ebp
mov %esp, %ebp
cli
xor %eax, %eax
mov %eax, _Idtr_prot
movw %ax, _Idtr_prot + 4
lidt _Idtr_prot
mov 0xc(%ebp), %eax // argument to program - bootargs to mach_kernel
mov 0x8(%ebp), %ecx // entry offset
mov $0x28, %ebx // segment
push %ebx
push %ecx
add $4, %esp // discard return address
mov $0x28, %eax // segment
xchg 4(%esp), %eax // argument to program - bootargs to mach_kernel
// set up %ds and %es
mov $0x20, %ebx
movw $0x20, %bx
movw %bx, %ds
movw %bx, %es
// AX, DI, and SI are clobbered.
//
LABEL(__switch_stack)
popl %eax # save return address
popl %edi # discard upper 16-bit
data32
addr32
movl OFFSET16(save_ss), %esi # new SS to SI
.code16
data32
addr32
pop %ax # save return address
pop %di # discard upper 16-bit
movw OFFSET16(save_ss), %si # new SS to SI
movl OFFSET16(save_sp), %edi # new SP to DI
addr32
mov %ss, OFFSET16(save_ss) # save current SS to memory
movw %ss, OFFSET16(save_ss) # save current SS to memory
data32
addr32
movl %esp, OFFSET16(save_sp) # save current SP to memory
cli
mov %si, %ss # switch stack
mov %di, %sp
mov %edi, %esp
sti
pushl %eax # push IP of caller onto the new stack
push %ax # push IP of caller onto the new stack
xorl %eax, %eax
xorl %esi, %esi
xorl %edi, %edi
xor %ax, %ax
xor %si, %si
xor %di, %di
ret
.code32
#ifndef BOOT1
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// loader()
//
LABEL(_loader)
enter $0, $0
pushfl
cli
pushal
#
###### Real Mode Begin ######
data32
call __switch_stack # Switch to NBP stack
.code16
calll __switch_stack # Switch to NBP stack
int $0x2b # Call NBP
data32
call __switch_stack # Restore stack
calll __switch_stack # Restore stack
data32
call __real_to_prot # Back to protected mode
calll __real_to_prot # Back to protected mode
.code32
###### Real Mode End ######
popal
popfl
leave
ret
#endif
trunk/i386/libsaio/bios.s
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#include <architecture/i386/asm_help.h>
#include "memory.h"
#define data32 .byte 0x66
#define addr32 .byte 0x67
#define O_INT 0
#define O_EAX 4
#define O_EBX 8
bits of code and data within the first 63.5k and modify the loaders to
be able to load more than 63.5k.
*/
.align 4
.align 2
save_eax: .space 4
.align 4
save_edx: .space 4
.align 2
save_es: .space 2
.align 2
save_flag: .space 2
.align 4
new_eax: .space 4
.align 4
new_edx: .space 4
.align 2
new_es: .space 2
.align 2
new_ds: .space 2
.section __INIT,__text // turbo - This code must reside within the first segment
.section __INIT,__text,regular,pure_instructions // turbo - This code must reside within the first segment
/*============================================================================
call __prot_to_real
data32
addr32
mov OFFSET16(new_eax), %eax
data32
addr32
.code16
mov new_eax, %eax // OFFSET16 not needed due to special opcode for ax/eax
mov OFFSET16(new_edx), %edx
data32
addr32
mov OFFSET16(new_es), %es
movw OFFSET16(new_es), %es
push %ds // Save DS
// Replace DS. WARNING: Don't access data until it's restored!
addr32
data32
mov OFFSET16(new_ds), %ds
movw OFFSET16(new_ds), %ds
do_int:
int $0x00
pop %ds // Restore DS before we do anything else
pushf
data32
addr32
movl %eax, OFFSET16(save_eax)
popl %eax // actually pop %ax
addr32
movl %eax, OFFSET16(save_flag) // actually movw
mov %eax, save_eax
pop %ax
mov %ax, save_flag
mov %es, %ax
addr32
movl %eax, OFFSET16(save_es) // actually movw
data32
call __real_to_prot
mov %ax, save_es
calll __real_to_prot
.code32
movl %edx, new_edx // save new edx before clobbering
movl save_edx, %edx
movl new_edx, %eax // now move it into buffer
trunk/i386/libsaio/table.c
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};
// turbo - GDT must be in first 64k segment
struct seg_desc __attribute__ ((section("__INIT,__data"))) Gdt[ NGDTENT ] = {
struct seg_desc __attribute__ ((section("__INIT,__data"), aligned(8))) Gdt[ NGDTENT ] = {
/* 0x0 : null */
{0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00},
byte granularity, 1MB limit, MEMBASE offset */
//{0xFFFF, MEMBASE, 0x00, 0x9E, 0x4F, 0x00},
{0xFFFF, 0x0000, 0x00, 0x9E, 0xCF, 0x00},
/* 0x10 : boot protected mode data segment
page granularity, 4GB limit, MEMBASE offset */
{0xFFFF, MEMBASE, 0x00, 0x92, 0xCF, 0x00},
trunk/i386/libsaio/saio_internal.h
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/* asm.s */
extern voidreal_to_prot(void);
extern voidprot_to_real(void);
extern voidhalt(void);
extern voidstartprog(unsigned int address, void *arg);
extern voidhalt(void) __attribute__((noreturn));
extern voidstartprog(unsigned int address, void *arg) __attribute__((noreturn));
extern voidloader(UInt32 code, UInt32 cmdptr);
extern uint64_tcomputeRand(void);
trunk/i386/boot2/mboot.c
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#define FIX_RETURN_ADDRESS_USING_FIRST_ARG(arg) \
RETURN_ADDRESS_USING_FIRST_ARG(arg) -= OFFSET_1MEG
extern void jump_to_chainbooter();
extern void jump_to_chainbooter() __attribute__((noreturn));
extern unsigned char chainbootdev;
extern unsigned char chainbootflag;
trunk/i386/boot2/boot.c
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// Notify modules that the kernel is about to be started
execute_hook("Kernel Start", (void *)kernelEntry, (void *)bootArgs, NULL, NULL);
if (interruptsAvailable)
{
DisableInterrupts();
}
// Masking out so that Lion doesn't doublefault
outb(0x21, 0xff);/* Maskout all interrupts Pic1 */
outb(0xa1, 0xff);/* Maskout all interrupts Pic2 */
// Notify modules that the kernel is about to be started
execute_hook("Kernel Start", (void*)kernelEntry, (void*)bootArgsPreLion, NULL, NULL);
if (interruptsAvailable)
{
DisableInterrupts();
}
startprog( kernelEntry, bootArgsPreLion );
}
trunk/i386/boot2/boot2.s
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#include "memory.h"
#include "mboot.h"
#define data32 .byte 0x66
#define retf .byte 0xcb
.file "boot2.s"
.section __INIT,__text// turbo - This initialization code must reside within the first segment
.section __INIT,__text,regular,pure_instructions// turbo - This initialization code must reside within the first segment
//.data
.section __INIT,__data// turbo - Data that must be in the first segment
# Returns:
#
LABEL(boot2) # Entry point at 0:BOOTER_ADDR (will be called by boot1)
pushl %ecx # Save general purpose registers
pushl %ebx
pushl %ebp
pushl %esi
pushl %edi
.code16
push %cx # Save general purpose registers
push %bx
push %bp
push %si
push %di
push %ds # Save DS, ES
push %es
mov %ax, %ds # Set DS and ES to match CS
mov %ax, %es
data32
call __switch_stack # Switch to new stack
calll __switch_stack # Switch to new stack
data32
call __real_to_prot # Enter protected mode.
calll __real_to_prot # Enter protected mode.
.code32
fninit # FPU init
# We are now in 32-bit protected mode.
call __prot_to_real # Back to real mode.
data32
call __switch_stack # Restore original stack
.code16
calll __switch_stack # Restore original stack
pop %es # Restore original ES and DS
pop %ds
popl %edi # Restore all general purpose registers
popl %esi # except EAX.
popl %ebp
popl %ebx
popl %ecx
pop %di # Restore all general purpose registers
pop %si # except AX.
pop %bp
pop %bx
pop %cx
retf # Hardcode a far return
lret # Far return
.code32
start_chain_boot:
xorl %edx, %edx
movb _chainbootdev, %dl # Setup DL with the BIOS device number
call __prot_to_real # Back to real mode.
data32
call __switch_stack # Restore original stack
.code16
calll __switch_stack # Restore original stack
pop %es # Restore original ES and DS
pop %ds
popl %edi # Restore all general purpose registers
popl %esi # except EAX.
popl %ebp
popl %ebx
popl %ecx
pop %di # Restore all general purpose registers
pop %si # except AX.
pop %bp
pop %bx
pop %cx
data32
ljmp $0, $0x7c00 # Jump to boot code already in memory
.code32
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Multiboot support added by David F. Elliott <dfe@cox.net> on 2007/06/26
# cannot do that and have GRUB find it because GRUB only searches the first
# 8k of the binary. Since __TEXT,__const follows __TEXT,__text (the code
# section) and since the code is well over 8k long, it doesn't work.
.align 4, 0x90 # Make sure we're on a 4-byte boundary. Required by Multiboot.
//.data - the entire __INIT segment is less than 1k
.section __INIT,__data// turbo
.align 2 # Make sure we're on a 4-byte boundary. Required by Multiboot.
_multiboot_header:
# magic (NOTE: this shows up as 02b0 ad1b in a hex dump)
.long MULTIBOOT_HEADER_MAGIC
# entry_addr
.long (_multiboot_entry + OFFSET_1MEG)
# Stick a couple of nop here so that we hopefully make disassemblers realize we have instructions again
nop
nop
nop
.align 8, 0x90 # Align to 8 byte boundary which should be enough nops
//.text
.section __INIT,__text// turbo
.align 3, 0x90 # Align to 8 byte boundary
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
_multiboot_entry:
# First thing's first, let's get ourselves a usable GDT.
# The desired offset in this case is exactly 1 MB higher than the
# assembler/linker thinks it is. As mentioned above, we use the kernel
# init code selector instead of the boot code selector.
jmp $0x28,$(Lpost_gdt_switch+OFFSET_1MEG)
ljmp $0x28,$(Lpost_gdt_switch+OFFSET_1MEG)
Lpost_gdt_switch:
# Now that we have the right code selector we also want the rest of the
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# _continue_at_low_address does some trickery to get the caller running from the low address with the right selector
.globl _continue_at_low_address
.align 4, 0x90
.align 2, 0x90
_continue_at_low_address:
# Our stack frame has been set up with the return address on top
# First, fix that to be 1 MB lower
lgdt _Gdtr
# Now jump to GDT selector 8 using the low address of this function
# This finally puts us in low memory in the right selector (0x08)
jmpl $0x08,$L_continue_at_low_address_next
ljmp $0x08,$L_continue_at_low_address_next
L_continue_at_low_address_next:
# We don't need to set ss,ds,es,fs, or gs because they are already 0x10
# and the old GDT had the same information for selector 0x10 as the new
call __prot_to_real # Back to real mode.
.code16
# TODO: Set SS:SP to something reasonable? For instance, Microsoft MBR
# code starts out by setting up the stack at 0:7c00 for itself and leaves
# that intact. Thus the stack by default will grow down from the code
# 0:fff0 and it seems that most boot code doesn't care and simply sets
# SS:SP itself as one of the first things it does.
data32
ljmp $0, $0x7c00 # Jump to boot code already in memory
.code32
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# _cause_crash jumps to offset 0 of a selector we know is not in our GDT
# This causes Parallels to output all sorts of nice debugging information
# We aren't using it right now so it's in an if 0 block.
#if 0
.globl _cause_crash
.align 4, 0x90
.align 2, 0x90
_cause_crash:
# Cause a crash, there is no GDT selector f0
jmp $0xf0,$0
ljmp $0xf0,$0
hlt
jmp _cause_crash
#endif
# See the comments above as to why we have OFFSET_1MEG.
//.data
.section __INIT,__data// turbo
.align 4, 0x90
.align 2
_Gdtr_high:
.word GDTLIMIT
.long vtop(_Gdt + OFFSET_1MEG)
trunk/i386/libsa/interrupts.c
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"addl $4, %%esp\n\t"
"iretl"
:);
__builtin_unreachable();
}
static
"addl $8, %%esp\n\t"
"iretl"
:);
__builtin_unreachable();
}
/*
trunk/i386/util/boot1-install/boot1-install.c
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554551
......
743740
744741
745742
746
747743
748744
749745
else
*pKind = _other;
break;
case _ntfs:
rc = 0;
break;
default:
break;
}
case _exfat:
case _hfs:
case _msdos:
case _ntfs:
break;
default:
unsupported();
trunk/CHANGES
1
12
23
34
- Zenith432 : Sanitize 16-bit assembly
- Zenith432 : Fix bug in malloc_init, use bios for enableA20()
- meklort : Slightly improve decive selection name - add os version.
- Zenith432 : Interrupt Management

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Revision: 2603