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Update the GAS compatible fathelp.S file to reflect the latest changes to the original file (freeldr PE conversion). This version is tested and works.

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svn path=/trunk/; revision=48701
This commit is contained in:
Timo Kreuzer 2010-09-05 16:03:08 +00:00
parent f276fcd056
commit 113c47805c
1 changed files with 15 additions and 19 deletions
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34
reactos/boot/freeldr/freeldr/arch/amd64/fathelp.S
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@ -4,10 +4,13 @@
.intel_syntax noprefix
//org 8000h
.text
.code16
#define BootSectorStackTop 0x7bf2
#define DataAreaStartHigh 0x2
#define DataAreaStartLow 0x4
@ -38,6 +41,8 @@
#define VolumeLabel 43
#define FileSystem 54
#define BootPartition 0x7dfd
// This code will be stored in the first 512 bytes
// of freeldr.sys. The first 3 bytes will be a jmp
@ -46,7 +51,6 @@
//
// This code is loaded at 0000:8000 so we have to
// encode a jmp instruction to jump to 0000:8200
//.org 0x8000
.global _mainCRTStartup // For Mingw32 builds where the linker looks for this symbol
_mainCRTStartup:
@ -119,14 +123,14 @@ LoadFile5:
jmp LoadFile // Load the next cluster (if any)
LoadFile_Done:
mov dl, [bp+BootDrive] // Load the boot drive into DL
mov dh, BootPartition // Load the boot partition into DH
push word ptr 0x0000
push word ptr 0x8000 // We will do a far return to 0000:8000h
// retf // Transfer control to ROSLDR
.byte 0xcb // == retf
mov dl,BYTE PTR [bp+BootDrive] // Load the boot drive into DL
mov dh,[BootPartition] // Load the boot partition into DH
push 0 // push segment (0x0000)
mov bx, [0x8000 + 0xA8] // load the RVA of the EntryPoint into eax
add bx, 0x8000 // RVA -> VA and skip 3 bytes (jump to fathelper code)
push bx // push offset
retf // Transfer control to FreeLoader
// Reads the entire FAT into memory at 7000:0000
ReadFatIntoMemory:
@ -225,15 +229,7 @@ IsFat12_Done:
msgLoading:
.ascii "Loading FreeLoader..."
.byte 0x0d,0x0a,0
msgLoading: .asciz "Loading FreeLoader...\r\n"
// times 510-($-$$) db 0 // Pad to 510 bytes
.org 0x1fe
.word 0x0aa55 // BootSector signature
// pseudo adresses
//.org 0x7dfd
BootPartition:
.org 0x1fe // Pad to 510 bytes
.word 0x0aa55 // BootSector signature