qemu-e2k/pc-bios/s390-ccw/main.c
Farhan Ali 99b72e0fbb pc-bios/s390-ccw: Use the ccw bios to start the network boot
We want to use the ccw bios to start final network boot. To do
this we use ccw bios to detect if the boot device is a virtio
network device and retrieve the start address of the
network boot image.

Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-02-28 12:04:48 +01:00

137 lines
3.6 KiB
C

/*
* S390 virtio-ccw loading program
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
* directory.
*/
#include "s390-ccw.h"
#include "virtio.h"
char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
static SubChannelId blk_schid = { .one = 1 };
IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
/*
* Priniciples of Operations (SA22-7832-09) chapter 17 requires that
* a subsystem-identification is at 184-187 and bytes 188-191 are zero
* after list-directed-IPL and ccw-IPL.
*/
void write_subsystem_identification(void)
{
SubChannelId *schid = (SubChannelId *) 184;
uint32_t *zeroes = (uint32_t *) 188;
*schid = blk_schid;
*zeroes = 0;
}
void panic(const char *string)
{
sclp_print(string);
disabled_wait();
while (1) { }
}
static bool find_dev(Schib *schib, int dev_no)
{
int i, r;
for (i = 0; i < 0x10000; i++) {
blk_schid.sch_no = i;
r = stsch_err(blk_schid, schib);
if ((r == 3) || (r == -EIO)) {
break;
}
if (!schib->pmcw.dnv) {
continue;
}
if (!virtio_is_supported(blk_schid)) {
continue;
}
/* Skip net devices since no IPLB is created and therefore no
* no network bootloader has been loaded
*/
if (virtio_get_device_type() == VIRTIO_ID_NET && dev_no < 0) {
continue;
}
if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) {
return true;
}
}
return false;
}
static void virtio_setup(void)
{
Schib schib;
int ssid;
bool found = false;
uint16_t dev_no;
VDev *vdev = virtio_get_device();
/*
* We unconditionally enable mss support. In every sane configuration,
* this will succeed; and even if it doesn't, stsch_err() can deal
* with the consequences.
*/
enable_mss_facility();
if (store_iplb(&iplb)) {
switch (iplb.pbt) {
case S390_IPL_TYPE_CCW:
dev_no = iplb.ccw.devno;
debug_print_int("device no. ", dev_no);
blk_schid.ssid = iplb.ccw.ssid & 0x3;
debug_print_int("ssid ", blk_schid.ssid);
found = find_dev(&schib, dev_no);
break;
case S390_IPL_TYPE_QEMU_SCSI:
vdev->scsi_device_selected = true;
vdev->selected_scsi_device.channel = iplb.scsi.channel;
vdev->selected_scsi_device.target = iplb.scsi.target;
vdev->selected_scsi_device.lun = iplb.scsi.lun;
blk_schid.ssid = iplb.scsi.ssid & 0x3;
found = find_dev(&schib, iplb.scsi.devno);
break;
default:
panic("List-directed IPL not supported yet!\n");
}
} else {
for (ssid = 0; ssid < 0x3; ssid++) {
blk_schid.ssid = ssid;
found = find_dev(&schib, -1);
if (found) {
break;
}
}
}
IPL_assert(found, "No virtio device found");
if (virtio_get_device_type() == VIRTIO_ID_NET) {
sclp_print("Network boot device detected\n");
vdev->netboot_start_addr = iplb.ccw.netboot_start_addr;
} else {
virtio_setup_device(blk_schid);
IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
}
}
int main(void)
{
sclp_setup();
virtio_setup();
zipl_load(); /* no return */
panic("Failed to load OS from hard disk\n");
return 0; /* make compiler happy */
}