[SeaBIOS] Re: [PATCH] floppy: Support CMOS setting outside QEMU
Dne 06. 08. 22 v 19:30 Peter Stuge napsal(a): > Kevin O'Connor wrote: >>> SeaBIOS can be used for booting legacy OS and also Linux is still using >>> CMOS address 0x10 to configure floppy controller. Under these assumptions >>> it makes sense to allow boot from CMOS defined floppy drives. >> >> There was never really a standard for the layout of CMOS nor for the >> encoding of floppy type. > > Ralf Brown's interrupt list disagrees: > > --8<-- CMOS.LST > --R10 > CMOS 10h - IBM - FLOPPY DRIVE TYPE > Note: a PC having a 5 1/4 1.2 Mb A: drive and a 1.44 Mb B: drive will > have a value of 24h in byte 10h. With a single 1.44 drive: 40h. > > Bitfields for floppy drives A/B types: > Bit(s) Description (Table C0007) > 7-4first floppy disk drive type (see #C0008) > 3-0second floppy disk drive type (see #C0008) > > (Table C0008) > Values for floppy drive type: > 00hno drive > 01h360 KB 5.25 Drive > 02h1.2 MB 5.25 Drive - note: not listed in PS/2 technical manual > 03h720 KB 3.5 Drive > 04h1.44 MB 3.5 Drive > 05h2.88 MB 3.5 drive > 06h-0Fh unused > SeeAlso: #C0007 > -->8-- > I agree, these will be probably used by older OSes and having the floppy type to be able to change without reflashing is definitely useful. > >> Currently, SeaBIOS doesn't use CMOS for anything when configured for >> coreboot mode and I think we should keep it that way. > > The first either 15 or 48 bytes are explicitly reserved on all > coreboot mainboards and coreboot checksums bytes 16-45 when built > to use an option table. > > >> If you have a machine with a floppy drive that you'd >> like to use with coorboot+SeaBIOS then you can set the "etc/floppy0" >> or "etc/floppy1" cbfs files to activate support in SeaBIOS. > > That's fine, but why reject the de-facto standard method? > Also few other bytes (14h) in this range could be used by legacy OSes too. > > Kind regards > > //Peter > ___ > SeaBIOS mailing list -- seabios@seabios.org > To unsubscribe send an email to seabios-le...@seabios.org ___ SeaBIOS mailing list -- seabios@seabios.org To unsubscribe send an email to seabios-le...@seabios.org
[SeaBIOS] Re: [PATCH] floppy: Support CMOS setting outside QEMU
Kevin O'Connor wrote: > > SeaBIOS can be used for booting legacy OS and also Linux is still using > > CMOS address 0x10 to configure floppy controller. Under these assumptions > > it makes sense to allow boot from CMOS defined floppy drives. > > There was never really a standard for the layout of CMOS nor for the > encoding of floppy type. Ralf Brown's interrupt list disagrees: --8<-- CMOS.LST --R10 CMOS 10h - IBM - FLOPPY DRIVE TYPE Note: a PC having a 5 1/4 1.2 Mb A: drive and a 1.44 Mb B: drive will have a value of 24h in byte 10h. With a single 1.44 drive: 40h. Bitfields for floppy drives A/B types: Bit(s) Description (Table C0007) 7-4first floppy disk drive type (see #C0008) 3-0second floppy disk drive type (see #C0008) (Table C0008) Values for floppy drive type: 00hno drive 01h360 KB 5.25 Drive 02h1.2 MB 5.25 Drive - note: not listed in PS/2 technical manual 03h720 KB 3.5 Drive 04h1.44 MB 3.5 Drive 05h2.88 MB 3.5 drive 06h-0Fh unused SeeAlso: #C0007 -->8-- > Currently, SeaBIOS doesn't use CMOS for anything when configured for > coreboot mode and I think we should keep it that way. The first either 15 or 48 bytes are explicitly reserved on all coreboot mainboards and coreboot checksums bytes 16-45 when built to use an option table. > If you have a machine with a floppy drive that you'd > like to use with coorboot+SeaBIOS then you can set the "etc/floppy0" > or "etc/floppy1" cbfs files to activate support in SeaBIOS. That's fine, but why reject the de-facto standard method? Kind regards //Peter ___ SeaBIOS mailing list -- seabios@seabios.org To unsubscribe send an email to seabios-le...@seabios.org
[SeaBIOS] Re: [PATCH] floppy: Support CMOS setting outside QEMU
On Wed, Jul 13, 2022 at 03:24:49AM +0200, Petr Cvek wrote: > SeaBIOS can be used for booting legacy OS and also Linux is still using > CMOS address 0x10 to configure floppy controller. Under these assumptions > it makes sense to allow boot from CMOS defined floppy drives. There was never really a standard for the layout of CMOS nor for the encoding of floppy type. Currently, SeaBIOS doesn't use CMOS for anything when configured for coreboot mode and I think we should keep it that way. If you have a machine with a floppy drive that you'd like to use with coorboot+SeaBIOS then you can set the "etc/floppy0" or "etc/floppy1" cbfs files to activate support in SeaBIOS. -Kevin ___ SeaBIOS mailing list -- seabios@seabios.org To unsubscribe send an email to seabios-le...@seabios.org
