MBRHelloWorld

MBR HelloWorld example written in c

How to make

Just type make

How to test this MBR

Install qemu, and type qemu-system-x86_64 boot.MBR.

Work with GRUB

It work with grub stage2 or stage1.5 perfectly. You can test this MBR work with GRUB stage2 images by fellowing command:

cat boot.MBR stage2 > tmpdisk && qemu-system-x86_64 tmpdisk

If you will not install stage1.5 into sector 1, you should set BOOTLOADER_START_SECTOR to compile it.

make CFLAGS="-DBOOTLOADER_START_SECTOR=12"

Loading your custom bootloader at specific address

Just set BOOTLOADER_LOAD_ADDRESS to boot.

make CFLAGS="-BOOTLOADER_LOAD_ADDRESS=0x7000"

This MBR will pass

Work with MBR partition table

Sure! It work perfectly. This is hexdump of our MBR, the partition table fill with nop, so we do not need worry about partition table.

00000000  e9 54 00 66 55 66 89 c2  66 89 e5 66 53 67 8a 0a  |.T.fUf..f..fSg..|
00000010  84 c9 74 0d 66 42 bb 01  00 b4 0e 88 c8 cd 10 eb  |..t.fB..........|
00000020  ec 66 5b 66 5d 66 c3 66  55 66 89 c2 66 89 e5 66  |.f[f]f.fUf..f..f|
00000030  b8 00 42 00 00 66 56 66  be 14 7d 00 00 cd 13 72  |..B..fVf..}....r|
00000040  02 eb 0e 66 b8 24 7d 00  00 66 e8 b4 ff ff ff eb  |...f.$}..f......|
00000050  fe 66 5e 66 5d 66 c3 66  55 66 89 e5 66 53 88 d3  |.f^f]f.fUf..fS..|
00000060  66 b8 30 7d 00 00 66 e8  97 ff ff ff 66 0f b6 c3  |f.0}..f.....f...|
00000070  66 e8 b1 ff ff ff 66 b8  3f 7d 00 00 66 e8 81 ff  |f.....f.?}..f...|
00000080  ff ff 66 b8 14 7d 00 00  89 c6 30 f6 88 da 66 b8  |..f..}....0...f.|
00000090  00 80 00 00 66 ff e0 00  14 00 00 00 00 00 00 00  |....f...........|
000000a0  01 7a 52 00 01 7c 08 01  1b 0c 04 04 88 01 00 00  |.zR..|..........|
000000b0  20 00 00 00 1c 00 00 00  4b ff ff ff 24 00 00 00  | .......K...$...|
000000c0  00 42 0e 08 85 02 46 0d  05 42 83 03 56 c3 42 c5  |.B....F..B..V.B.|
000000d0  0c 04 04 00 20 00 00 00  40 00 00 00 4b ff ff ff  |.... ...@...K...|
000000e0  30 00 00 00 00 42 0e 08  85 02 46 0d 05 48 86 03  |0....B....F..H..|
000000f0  5c c6 42 c5 0c 04 04 00  18 00 00 00 64 00 00 00  |\.B.........d...|
00000100  57 ff ff ff 40 00 00 00  00 42 0e 08 85 02 43 0d  |W...@....B....C.|
00000110  05 42 83 03 10 00 01 00  00 80 00 00 01 00 00 00  |.B..............|
00000120  00 00 00 00 42 6f 6f 74  20 66 61 69 6c 65 64 00  |....Boot failed.|
00000130  48 65 6c 6c 6f 20 57 6f  72 6c 64 21 0d 0a 00 42  |Hello World!...B|
00000140  6f 6f 74 20 62 6f 6f 74  6c 6f 61 64 65 72 2e 2e  |oot bootloader..|
00000150  2e 0d 0a 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000160  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000170  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000180  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000190  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001a0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001c0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|

Known issue

It will not worked if you are running on non supported LBA BIOS.

License

WTFPL

darkautism/MBRHelloWorld