Unable to read NetBSD/macppc current images with QEMU

[Mark Cave-Ayland <mark.cave-ayland%ilande.co.uk@localhost>]

Hi all,

As one of the QEMU Mac machine maintainers I've been doing some testing
against NetBSD 8.0 and NetBSD current, and I am unable to boot
NetBSD/macppc current ISO images under qemu-system-ppc due to OpenBIOS
no longer being able to read any files on it:


NetBSD-8.0-macppc.iso (works):

$ ./qemu-system-ppc -cdrom NetBSD-8.0-macppc.iso -boot d -nographic

>> =============================================================
>> OpenBIOS 1.1 [Jun 18 2018 18:20]
>> Configuration device id QEMU version 1 machine id 2
>> CPUs: 1
>> Memory: 128M
>> UUID: 00000000-0000-0000-0000-000000000000
>> CPU type PowerPC,750
milliseconds isn't unique.
Welcome to OpenBIOS v1.1 built on Jun 18 2018 18:20
Trying cd:,\\:tbxi...
No valid state has been set by load or init-program

0 > dir cd:,\
     32768 2018-07-18 07:21:17 Desktop DB
         0 2018-07-18 07:21:17 Desktop DF
    327680 2018-07-18 07:21:17 macppc\
     63762 2018-07-18 07:20:23 ofwboot
    350334 2018-07-18 07:20:22 ofwboot.xcf
    131072 2018-07-18 07:21:17 shared\
 ok
0 >

$ file NetBSD-8.0-macppc.iso
NetBSD-8.0-macppc.iso: DOS/MBR boot sector


NetBSD-8.99.24-macppc.iso downloaded yesterday from
https://nyftp.netbsd.org/pub/NetBSD-daily/HEAD/201808272010Z/images/NetBSD-8.99.24-macppc.iso
(fails):

$ ./qemu-system-ppc -cdrom NetBSD-8.99.24-macppc.iso -boot d -nographic

>> =============================================================
>> OpenBIOS 1.1 [Jun 18 2018 18:20]
>> Configuration device id QEMU version 1 machine id 2
>> CPUs: 1
>> Memory: 128M
>> UUID: 00000000-0000-0000-0000-000000000000
>> CPU type PowerPC,750
milliseconds isn't unique.
Welcome to OpenBIOS v1.1 built on Jun 18 2018 18:20
Trying cd:,\\:tbxi...
Trying cd:,\ppc\bootinfo.txt...
Trying cd:,%BOOT...
No valid state has been set by load or init-program

0 > dir cd:,\
Unable to locate device cd:, ok
0 >

$ file NetBSD-8.99.24-macppc.iso
NetBSD-8.99.24-macppc.iso: ISO 9660 CD-ROM filesystem data 'NETBSD_89924'


Has there been a deliberate change in the way that NetBSD/macppc ISO
images are being generated since the 8.0 release? Possibly this is
tickling a bug in the OpenBIOS ISO9660 driver but I thought it worth
asking first to find out if there is anything special happening when
building the latest current ISO images?


ATB,

Mark.