If no boot device has been specified (via "bootindex=..."), the s390-ccw bios scans through all devices to find a bootable device. But so far, it stops at the very first block device (including virtio-scsi controllers without attached devices) that it finds, no matter whether it is bootable or not. That leads to some weird situatation where it is e.g. possible to boot via:
qemu-system-s390x -hda /path/to/disk.qcow2 but not if there is e.g. a virtio-scsi controller specified before: qemu-system-s390x -device virtio-scsi -hda /path/to/disk.qcow2 While using "bootindex=..." is clearly the preferred way of booting on s390x, we still can make the life for the users at least a little bit easier if we look at all available devices to find a bootable one. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1846975 Signed-off-by: Thomas Huth <th...@redhat.com> --- pc-bios/s390-ccw/main.c | 46 +++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 15 deletions(-) diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c index 3cd01cd80f..0af872f9e3 100644 --- a/pc-bios/s390-ccw/main.c +++ b/pc-bios/s390-ccw/main.c @@ -182,20 +182,8 @@ static void boot_setup(void) static void find_boot_device(void) { VDev *vdev = virtio_get_device(); - int ssid; bool found; - if (!have_iplb) { - for (ssid = 0; ssid < 0x3; ssid++) { - blk_schid.ssid = ssid; - found = find_subch(-1); - if (found) { - return; - } - } - panic("Could not find a suitable boot device (none specified)\n"); - } - switch (iplb.pbt) { case S390_IPL_TYPE_CCW: debug_print_int("device no. ", iplb.ccw.devno); @@ -260,14 +248,42 @@ static void ipl_boot_device(void) } } +/* + * No boot device has been specified, so we have to scan through the + * channels to find one. + */ +static void probe_boot_device(void) +{ + int ssid, sch_no, ret; + + for (ssid = 0; ssid < 0x3; ssid++) { + blk_schid.ssid = ssid; + for (sch_no = 0; sch_no < 0x10000; sch_no++) { + ret = check_sch_no(-1, sch_no); + if (ret < 0) { + break; + } + if (ret == true) { + ipl_boot_device(); /* Only returns if unsuccessful */ + } + } + } + + sclp_print("Could not find a suitable boot device (none specified)\n"); +} + int main(void) { sclp_setup(); css_setup(); boot_setup(); - find_boot_device(); - enable_subchannel(blk_schid); - ipl_boot_device(); + if (have_iplb) { + find_boot_device(); + enable_subchannel(blk_schid); + ipl_boot_device(); + } else { + probe_boot_device(); + } panic("Failed to load OS from hard disk\n"); return 0; /* make compiler happy */ -- 2.18.1
