/*
* 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 "libc.h"
#include "helper.h"
#include "s390-arch.h"
#include "s390-ccw.h"
#include "cio.h"
#include "virtio.h"
#include "dasd-ipl.h"
char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
static SubChannelId blk_schid = { .one = 1 };
static char loadparm_str[LOADPARM_LEN + 1];
QemuIplParameters qipl;
IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
static bool have_iplb;
static uint16_t cutype;
LowCore *lowcore; /* Yes, this *is* a pointer to address 0 */
#define LOADPARM_PROMPT "PROMPT "
#define LOADPARM_EMPTY " "
#define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL)
/*
* Principles 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)
{
lowcore->subchannel_id = blk_schid.sch_id;
lowcore->subchannel_nr = blk_schid.sch_no;
lowcore->io_int_parm = 0;
}
void write_iplb_location(void)
{
lowcore->ptr_iplb = ptr2u32(&iplb);
}
unsigned int get_loadparm_index(void)
{
return atoui(loadparm_str);
}
/*
* Find the subchannel connected to the given device (dev_no) and fill in the
* subchannel information block (schib) with the connected subchannel's info.
* NOTE: The global variable blk_schid is updated to contain the subchannel
* information.
*
* If the caller gives dev_no=-1 then the user did not specify a boot device.
* In this case we'll just use the first potentially bootable device we find.
*/
static bool find_subch(int dev_no)
{
Schib schib;
int i, r;
bool is_virtio;
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;
}
enable_subchannel(blk_schid);
cutype = cu_type(blk_schid);
/*
* Note: we always have to run virtio_is_supported() here to make
* sure that the vdev.senseid data gets pre-initialized correctly
*/
is_virtio = virtio_is_supported(blk_schid);
/* No specific devno given, just return 1st possibly bootable device */
if (dev_no < 0) {
switch (cutype) {
case CU_TYPE_VIRTIO:
if (is_virtio) {
/*
* Skip net devices since no IPLB is created and therefore
* no network bootloader has been loaded
*/
if (virtio_get_device_type() != VIRTIO_ID_NET) {
return true;
}
}
continue;
case CU_TYPE_DASD_3990:
case CU_TYPE_DASD_2107:
return true;
default:
continue;
}
}
/* Caller asked for a specific devno */
if (schib.pmcw.dev == dev_no) {
return true;
}
}
return false;
}
static void menu_setup(void)
{
if (memcmp(loadparm_str, LOADPARM_PROMPT, LOADPARM_LEN) == 0) {
menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
return;
}
/* If loadparm was set to any other value, then do not enable menu */
if (memcmp(loadparm_str, LOADPARM_EMPTY, LOADPARM_LEN) != 0) {
return;
}
switch (iplb.pbt) {
case S390_IPL_TYPE_CCW:
case S390_IPL_TYPE_QEMU_SCSI:
menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK,
qipl.boot_menu_timeout);
return;
}
}
/*
* Initialize the channel I/O subsystem so we can talk to our ipl/boot device.
*/
static void css_setup(void)
{
/*
* Unconditionally enable mss support. In every sane configuration this
* will succeed; and even if it doesn't, stsch_err() can handle it.
*/
enable_mss_facility();
}
/*
* Collect various pieces of information from the hypervisor/hardware that
* we'll use to determine exactly how we'll boot.
*/
static void boot_setup(void)
{
char lpmsg[] = "LOADPARM=[________]\n";
sclp_get_loadparm_ascii(loadparm_str);
memcpy(lpmsg + 10, loadparm_str, 8);
sclp_print(lpmsg);
have_iplb = store_iplb(&iplb);
}
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);
blk_schid.ssid = iplb.ccw.ssid & 0x3;
debug_print_int("ssid ", blk_schid.ssid);
found = find_subch(iplb.ccw.devno);
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_subch(iplb.scsi.devno);
break;
default:
panic("List-directed IPL not supported yet!\n");
}
IPL_assert(found, "Boot device not found\n");
}
static void virtio_setup(void)
{
VDev *vdev = virtio_get_device();
QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;
memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));
if (have_iplb) {
menu_setup();
}
if (virtio_get_device_type() == VIRTIO_ID_NET) {
sclp_print("Network boot device detected\n");
vdev->netboot_start_addr = qipl.netboot_start_addr;
} else {
virtio_blk_setup_device(blk_schid);
IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
}
}
int main(void)
{
sclp_setup();
css_setup();
boot_setup();
find_boot_device();
enable_subchannel(blk_schid);
switch (cutype) {
case CU_TYPE_DASD_3990:
case CU_TYPE_DASD_2107:
dasd_ipl(blk_schid, cutype); /* no return */
break;
case CU_TYPE_VIRTIO:
virtio_setup();
zipl_load(); /* no return */
break;
default:
print_int("Attempting to boot from unexpected device type", cutype);
panic("");
}
panic("Failed to load OS from hard disk\n");
return 0; /* make compiler happy */
}
