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revert unwanted changes

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svn path=/branches/cmake-bringup/; revision=49597
This commit is contained in:
Timo Kreuzer
2010-11-15 19:45:52 +00:00
parent 3ebe2aa8f7
commit b7383087f4
1 changed files with 50 additions and 66 deletions
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boot/freeldr/freeldr/arch/i386/arch.S
+50 -66
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@@ -17,19 +17,16 @@
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <asm.inc>
.intel_syntax noprefix
#define HEX(y) 0x##y
#define ASM
#include <arch.h>
#include <multiboot.h>
EXTERN _BootMain:PROC
EXTERN __bss_start__:DWORD
EXTERN __bss_end__:DWORD
EXTERN i386idtptr:FWORD
.code16
.code16
PUBLIC RealEntryPoint
RealEntryPoint:
EXTERN(RealEntryPoint)
cli
@@ -47,10 +44,9 @@ RealEntryPoint:
sti
/* Init pmode */
call switch_to_prot
call switch_to_prot
.endcode16
.code32
.code32
/* Zero BootDrive and BootPartition */
xor eax, eax
@@ -68,7 +64,7 @@ RealEntryPoint:
call _BootMain
call switch_to_real
.code16
.code16
int HEX(19)
@@ -82,8 +78,9 @@ stop:
* Switches the processor to protected mode
* it destroys eax
*/
PUBLIC switch_to_prot
switch_to_prot:
EXTERN(switch_to_prot)
.code16
cli /* None of these */
@@ -107,9 +104,9 @@ switch_to_prot:
mov word ptr ds:[stack16], sp
/* Load the GDT */
lgdt gdtptr
lgdt gdtptr
/* Load the IDT */
lidt i386idtptr
lidt i386idtptr
/* Enable Protected Mode */
mov eax, cr0
@@ -117,12 +114,12 @@ switch_to_prot:
mov cr0, eax
/* Clear prefetch queue & correct CS */
ljmp16 PMODE_CS, inpmode
//ljmp PMODE_CS, inpmode
jmp far ptr PMODE_CS:inpmode
inpmode:
.endcode16
.code32
inpmode:
/* Setup segment selectors */
mov ax, PMODE_DS
mov ds, ax
@@ -142,8 +139,9 @@ inpmode:
* Switches the processor back to real mode
* it destroys eax
*/
PUBLIC switch_to_real
switch_to_real:
EXTERN(switch_to_real)
.code32
/* We don't know what values are currently */
/* in the segment registers. So we are */
@@ -184,7 +182,7 @@ switch_to_real16:
mov cr0, eax
/* Clear prefetch queue & correct CS */
//ljmp16 0, offset inrmode
//ljmp $0, $inrmode
jmp far ptr 0:inrmode
inrmode:
@@ -209,7 +207,7 @@ inrmode:
push word ptr ds:[code16ret]
/* Load IDTR with real mode value */
lidt rmode_idtptr
lidt rmode_idtptr
sti /* These are ok now */
@@ -220,8 +218,9 @@ inrmode:
/*
* Needed for enabling the a20 address line
*/
.code16
empty_8042:
.word HEX(00eb), HEX(00eb) // jmp $+2, jmp $+2
.word 0x00eb,0x00eb // jmp $+2, jmp $+2
in al, HEX(64)
cmp al, HEX(ff) // legacy-free machine without keyboard
jz empty_8042_ret // controllers on Intel Macs read back 0xFF
@@ -230,14 +229,11 @@ empty_8042:
empty_8042_ret:
ret
.endcode16
.code32
/*
* Enable the A20 address line (to allow access to over 1mb)
*/
PUBLIC _EnableA20
_EnableA20:
EXTERN(_EnableA20)
.code32
pusha
@@ -252,9 +248,7 @@ _EnableA20:
out HEX(60), al
call empty_8042
call switch_to_prot
.endcode16
.code32
.code32
popa
@@ -263,26 +257,23 @@ _EnableA20:
/*
* Disable the A20 address line
*/
PUBLIC _DisableA20
_DisableA20:
EXTERN(_DisableA20)
.code32
pusha
call switch_to_real
.code16
.code16
call empty_8042
call empty_8042
mov al, HEX(D1) // command write
out HEX(64), al
call empty_8042
mov al, HEX(DD) // A20 off
out HEX(60), al
call empty_8042
call switch_to_prot
.endcode16
.code32
call empty_8042
call switch_to_prot
.code32
popa
@@ -310,7 +301,7 @@ _DisableA20:
#define INITIAL_BASE HEX(200000)
/* Align 32 bits boundary */
.align 4
.align 4
/* Multiboot header */
MultibootHeader:
@@ -340,10 +331,10 @@ MultibootEntry:
/* Although the multiboot spec says we should be called with the
* segment registers set to 4GB flat mode, let's be sure and set up
* our own */
lgdt gdtptrhigh + INITIAL_BASE - FREELDR_BASE
lgdt gdtptrhigh + INITIAL_BASE - FREELDR_BASE
/* Reload segment selectors */
ljmp PMODE_CS, (mb1 + INITIAL_BASE - FREELDR_BASE)
//jmp far ptr PMODE_CS: (offset mb1 + INITIAL_BASE - FREELDR_BASE)
//ljmp $PMODE_CS, $(mb1 + INITIAL_BASE - FREELDR_BASE)
jmp far ptr PMODE_CS: (mb1 + INITIAL_BASE - FREELDR_BASE)
mb1:
mov dx, PMODE_DS
mov ds, dx
@@ -383,13 +374,13 @@ mb3:
rep movsd
/* Load the GDT and IDT */
lgdt gdtptr
lidt i386idtptr
lgdt gdtptr
lidt i386idtptr
/* Clear prefetch queue & correct CS,
* jump to low mem */
ljmp PMODE_CS, mb4
//jmp far ptr PMODE_CS:mb4
//ljmp $PMODE_CS, $mb4
jmp far ptr PMODE_CS:mb4
mb4:
/* Reload segment selectors */
mov dx, PMODE_DS
@@ -425,17 +416,15 @@ mb7:
/* GO! */
push eax
call _BootMain
call _BootMain
mbfail:
call switch_to_real
.code16
int HEX(19)
mbstop:
jmp mbstop /* We should never get here */
.code16
int 0x19
mbstop: jmp mbstop /* We should never get here */
.endcode16
.code32
.code32
/* 16-bit stack pointer */
stack16:
@@ -507,13 +496,8 @@ mb_info:
cmdline:
.fill CMDLINE_SIZE, 1, 0
PUBLIC _BootDrive
_BootDrive:
EXTERN(_BootDrive)
.long 0
PUBLIC _BootPartition
_BootPartition:
EXTERN(_BootPartition)
.long 0
END