search for: missing_os

This patches add support for dynamic sectors to GPT MBR code. First 3 patches are trick and optimizations to gain some space for the forth patch. I have a modified version of SeaBIOS, some code and some script o test it I'll send on a different mail.

...* SizeOfPartitionEntry */ pushw %ax pushw %cx mulw %cx - shrw $9,%ax + divw -6(%bp) /* %dx == 0 here */ xchgw %ax,%cx incw %cx @@ -214,7 +230,7 @@ boot: movl (32+20)(%si),%eax movl (36+20)(%si),%edx call read_sector_phdr - cmpw $0xaa55, -2(%bx) + cmpw $0xaa55, (0x7c00+0x1fe) jne missing_os /* Not a valid boot sector */ movw %bp, %sp /* driveno == bootsec-6 */ popw %dx /* dl -> drive number */ @@ -258,12 +274,12 @@ read_sector: /* This chunk is skipped if we have ebios */ /* Do not clobber %es:%bx or %edx:%eax before this chunk! */ read_sector_cbios: - divl -6(%bp) /* sec...

This set of patches add some support for sector size >512. Currently it fixes extlinux, MBR for GPT and ext partitions. Other code is unaffected. This set of patches has been tested on a read Dell machine running a beta firmware.

...e no_xfs + + /* We put the Syslinux boot sector at offset 0x800 (4 sectors), so we + * need to adjust %eax (%eax + 4) to read the right sector into 0x7C00. + */ + addl $0x800 >> 0x09, %eax /* plus 4 sectors */ + call read_sector + jc disk_error + +no_xfs: cmpw $0xaa55, (bootsec+510) jne missing_os /* Not a valid boot sector */ movw $driveno, %sp /* driveno == bootsec-6 */