Hi all Since USB ROM has already added into the booting menu list(IPL table), and the UHCI stack can be run well in usbrom now, i have some issues to confirm, any advices are welcome. 1) <<Plug and Play BIOS Specification>>Page21, There is an r Return Status from Initialization Call of OPTION ROM. Which used to let the bios know the status. But it seems Seabios does not check the return code. Is that OK? 2) After Seabios make an far call into the BEV, the OPTION ROM should begin to load OS.if it failed, it can return back to BIOS. But it can not return back with my USB OPTION ROM, Is there any configuration I should set? 3) In my eyes, OPTION ROM hook int13 after jump into BEV, not in the initialization.But after that how does it jump into the booting code which located in the USB disk?
BTW: Kevin: I looked the code of Seabios ata.c to learn how seabios booting OS from ata disk. some question i have: 1) ATA used add_bcv_hd to add ata disk into IPL table. it's type is IPL_TYPE_HARDDISK(0x02). It's vector is the driver id. how does seabios know the bootstrap vector based the driver ID? what does ata fill FDPT area for? Should my usbrom do the same? For my usbrom, i should not use add_bcv to add option rom into IPL ? or just take the ata as example?