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[BOOTSECTORS]

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- Use the old fat.S source for compiling the FAT12 boot sector, until FATX.S is completely implemented.
- Fix an assembly error in FATX.S
- In comments I added experimental FAT12/16/32 targets based on Timo's FATX.S.

svn path=/trunk/; revision=70423
This commit is contained in:
Hermès Bélusca-Maïto 2015-12-26 16:57:41 +00:00
parent 9d67515773
commit c6ab198d15
2 changed files with 25 additions and 11 deletions
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15
reactos/boot/freeldr/bootsect/CMakeLists.txt
View file

@ -3,8 +3,21 @@ if(ARCH STREQUAL "i386" OR ARCH STREQUAL "amd64")
CreateBootSectorTarget(dosmbr ${CMAKE_CURRENT_SOURCE_DIR}/dosmbr.S ${CMAKE_CURRENT_BINARY_DIR}/dosmbr.bin 7c00)
CreateBootSectorTarget(ext2 ${CMAKE_CURRENT_SOURCE_DIR}/ext2.S ${CMAKE_CURRENT_BINARY_DIR}/ext2.bin 0)
CreateBootSectorTarget(fat ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S ${CMAKE_CURRENT_BINARY_DIR}/fat.bin 7c00)
CreateBootSectorTarget(fat ${CMAKE_CURRENT_SOURCE_DIR}/fat.S ${CMAKE_CURRENT_BINARY_DIR}/fat.bin 7c00)
CreateBootSectorTarget(fat32 ${CMAKE_CURRENT_SOURCE_DIR}/fat32.S ${CMAKE_CURRENT_BINARY_DIR}/fat32.bin 7c00)
## New versions using FATX.S (experimental)
# add_definitions(-DFAT12)
# CreateBootSectorTarget(fat_new ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S ${CMAKE_CURRENT_BINARY_DIR}/fat_new.bin 7c00)
# remove_definitions(-DFAT12)
# add_definitions(-DFAT16)
# CreateBootSectorTarget(fat16_new ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S ${CMAKE_CURRENT_BINARY_DIR}/fat16_new.bin 7c00)
# remove_definitions(-DFAT16)
# add_definitions(-DFAT32)
# CreateBootSectorTarget(fat32_new ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S ${CMAKE_CURRENT_BINARY_DIR}/fat32_new.bin 7c00)
# remove_definitions(-DFAT32)
CreateBootSectorTarget(isoboot ${CMAKE_CURRENT_SOURCE_DIR}/isoboot.S ${CMAKE_CURRENT_BINARY_DIR}/isoboot.bin 7000)
CreateBootSectorTarget(isobtrt ${CMAKE_CURRENT_SOURCE_DIR}/isobtrt.S ${CMAKE_CURRENT_BINARY_DIR}/isobtrt.bin 7000)

21
reactos/boot/freeldr/bootsect/fatx.S
View file

@ -64,7 +64,8 @@ PutCharsOffset = BootSectorStackTop + 20 /* word */
******************************************************************************/
/* We have 3 bytes at the entry point to jump over the data area */
start:
jmp short main
jmp short main // FIXME: When compiling FAT32, assembler will complain
// that the label is too far... Need investigation!
nop
/* Here starts the BIOS Parameter Block (BPB) data.
@ -233,8 +234,8 @@ main:
add eax, dword ptr BP_REL(HiddenSectors)
/* Load sector count into ecx */
#if FAT32
mov ecx, BP_REL(SectorsPerFatBig)
#ifdef FAT32
mov ecx, dword ptr BP_REL(SectorsPerFatBig)
#else
movzx ecx, word ptr BP_REL(SectorsPerFat)
#endif
@ -350,7 +351,7 @@ main:
dec dx
jnz .CheckDirEntry
#if FAT32
#ifdef FAT32
/* Check to see if this was the last cluster in the chain */
cmp eax, HEX(0ffffff8)
jnb BootFailure
@ -367,7 +368,7 @@ main:
.FoundFreeLoader:
/* Load the cluster number of freeldr into eax */
#if FAT32
#ifdef FAT32
#error unsupported
#else
movzx eax, word ptr es:[bx + HEX(1A)]
@ -384,9 +385,9 @@ main:
call ReadCluster
/* Check if this is the last cluster in the chain */
#if FAT32
#if defined(FAT32)
cmp eax, HEX(0ffffff8)
#elif FAT12
#elif defined(FAT12)
cmp ax, HEX(0ff8)
#else
cmp ax, HEX(0fff8)
@ -453,9 +454,9 @@ ReadCluster:
/* Save ES */
push es
#if FAT32
#error FAT23 not implemented
#elif FAT12
#if defined(FAT32)
#error FAT32 not implemented
#elif defined(FAT12)
#error FAT12 not implemented
#else
/* DX:AX = AX * 2 (since FAT16 entries are 2 bytes) */