Legacy bios fail to boot into syslinux on C720

[Rong]

Hi,

I'm trying to get the legacy bios to boot the syslinux on partition 12 on ssd, below is the command I used:
>> cgpt boot -i 12 /dev/sda
>> cgpt boot -p /dev/sda
I can confirm that the syslinux files is indeed in the partition 12, which is vfat-formated. However I can never get it booted, the legacy bios alwasy displays "Missing OS"

I also tried to put the syslinux files on sdb3 of a usb drive, which has the same partition layout as SSD. After running:
>> cgpt boot -i 3 /dev/sdb
>> cgpt boot -p /dev/sdb
it turned out I can not boot legacy syslinux in this way either.

But according to http://dev.chromium.org/chromium-os/how-tos-and-troubleshooting/kernel-faq#TOC-Testing-with-a-legacy-BIOS ,this should work. Could you help me to get syslinux working?

Rong

[Mike Frysinger]

i don't think seabios handles the GPT flags the way our CrOS firmware does.  that's kind of the point of the legacy bios -- it just boots whatever is in the first sector of the disk.

i'm not sure we initialize our disk at all with executable code.  i wonder what would happen if you did `syslinux /dev/sda`.

-mike

--
--
Chromium OS discuss mailing list: chromium-...@chromium.org
View archives, change email options, or unsubscribe:
http://groups.google.com/a/chromium.org/group/chromium-os-discuss?hl=en

[Rong]

I did tried that, but seabios complains:
"Booting from hard disk...
Missing OS
Booting from Floppy...
Boot failed: could not read the boot disk

No bootable device
"

Seems I need activate partition 12 in pmbr. I tried "cgpt boot -i 12 /dev/sda", but it reverses the effect of gptmbr.bin.