qemu/pc-bios/s390-ccw/main.c
Christian Borntraeger 2be9d2927c s390-ccw.img: Allow bigger ramdisk sizes or offsets
The s390-ccw bios creates the the virtqueue at 100MB. For
big ramdisks or offsets (via zipl) this gets overwritten.
As a quick band-aid, lets move the virtqueue into the bss
section, which is at 0x7f00000. As the bios code (text) is
at 0x7e00000 we can now handle ramdisk which are  ~27MB
bigger.

Long term we want to make the s390-ccw bios position
independent and load of at the end of memory.

Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <1425310029-53396-2-git-send-email-borntraeger@de.ibm.com>
2015-03-10 09:26:23 +01:00

101 lines
2.4 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)));
char ring_area[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
uint64_t boot_value;
static struct subchannel_id blk_schid = { .one = 1 };
/*
* 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)
{
struct subchannel_id *schid = (struct subchannel_id *) 184;
uint32_t *zeroes = (uint32_t *) 188;
*schid = blk_schid;
*zeroes = 0;
}
void virtio_panic(const char *string)
{
sclp_print(string);
disabled_wait();
while (1) { }
}
static void virtio_setup(uint64_t dev_info)
{
struct schib schib;
int i;
int r;
bool found = false;
bool check_devno = false;
uint16_t dev_no = -1;
if (dev_info != -1) {
check_devno = true;
dev_no = dev_info & 0xffff;
debug_print_int("device no. ", dev_no);
blk_schid.ssid = (dev_info >> 16) & 0x3;
if (blk_schid.ssid != 0) {
debug_print_int("ssid ", blk_schid.ssid);
if (enable_mss_facility() != 0) {
virtio_panic("Failed to enable mss facility\n");
}
}
}
for (i = 0; i < 0x10000; i++) {
blk_schid.sch_no = i;
r = stsch_err(blk_schid, &schib);
if (r == 3) {
break;
}
if (schib.pmcw.dnv) {
if (!check_devno || (schib.pmcw.dev == dev_no)) {
if (virtio_is_blk(blk_schid)) {
found = true;
break;
}
}
}
}
if (!found) {
virtio_panic("No virtio-blk device found!\n");
}
virtio_setup_block(blk_schid);
if (!virtio_ipl_disk_is_valid()) {
virtio_panic("No valid hard disk detected.\n");
}
}
int main(void)
{
sclp_setup();
debug_print_int("boot reg[7] ", boot_value);
virtio_setup(boot_value);
zipl_load(); /* no return */
virtio_panic("Failed to load OS from hard disk\n");
return 0; /* make compiler happy */
}