qemu/pc-bios/s390-ccw/main.c
Thomas Huth e31f08dc74 pc-bios/s390-ccw: Move the stack array into start.S
The stack array is only referenced from the start-up code (which is
shared between the s390-ccw.img and the s390-netboot.img), but it is
currently declared twice, once in main.c and once in netmain.c.
It makes more sense to declare this in start.S instead - which will
also be helpful in the next patch, since we need to mention the .bss
section in start.S in that patch.

While we're at it, let's also drop the huge alignment of the stack,
since there is no technical requirement for aligning it to page
boundaries.

Message-Id: <20230627074703.99608-4-thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-06-29 20:45:12 +02:00

307 lines
7.8 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 "libc.h"
#include "helper.h"
#include "s390-arch.h"
#include "s390-ccw.h"
#include "cio.h"
#include "virtio.h"
#include "virtio-scsi.h"
#include "dasd-ipl.h"
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)
{
if (cutype == CU_TYPE_VIRTIO && virtio_get_device_type() != VIRTIO_ID_NET) {
lowcore->ptr_iplb = ptr2u32(&iplb);
}
}
unsigned int get_loadparm_index(void)
{
return atoui(loadparm_str);
}
static int is_dev_possibly_bootable(int dev_no, int sch_no)
{
bool is_virtio;
Schib schib;
int r;
blk_schid.sch_no = sch_no;
r = stsch_err(blk_schid, &schib);
if (r == 3 || r == -EIO) {
return -ENODEV;
}
if (!schib.pmcw.dnv) {
return false;
}
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 whether the device is possibly bootable */
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;
}
}
return false;
case CU_TYPE_DASD_3990:
case CU_TYPE_DASD_2107:
return true;
default:
return false;
}
}
/* Caller asked for a specific devno */
if (schib.pmcw.dev == dev_no) {
return true;
}
return false;
}
/*
* 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)
{
int i, r;
for (i = 0; i < 0x10000; i++) {
r = is_dev_possibly_bootable(dev_no, i);
if (r < 0) {
break;
}
if (r == true) {
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);
/*
* Clear out any potential S390EP magic (see jump_to_low_kernel()),
* so we don't taint our decision-making process during a reboot.
*/
memset((char *)S390EP, 0, 6);
have_iplb = store_iplb(&iplb);
}
static void find_boot_device(void)
{
VDev *vdev = virtio_get_device();
bool found;
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 int virtio_setup(void)
{
VDev *vdev = virtio_get_device();
QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;
int ret;
memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));
if (have_iplb) {
menu_setup();
}
switch (vdev->senseid.cu_model) {
case VIRTIO_ID_NET:
sclp_print("Network boot device detected\n");
vdev->netboot_start_addr = qipl.netboot_start_addr;
return 0;
case VIRTIO_ID_BLOCK:
ret = virtio_blk_setup_device(blk_schid);
break;
case VIRTIO_ID_SCSI:
ret = virtio_scsi_setup_device(blk_schid);
break;
default:
panic("\n! No IPL device available !\n");
}
if (!ret) {
IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
}
return ret;
}
static void ipl_boot_device(void)
{
switch (cutype) {
case CU_TYPE_DASD_3990:
case CU_TYPE_DASD_2107:
dasd_ipl(blk_schid, cutype); /* no return */
break;
case CU_TYPE_VIRTIO:
if (virtio_setup() == 0) {
zipl_load(); /* Only returns in case of errors */
}
break;
default:
print_int("Attempting to boot from unexpected device type", cutype);
panic("\nBoot failed.\n");
}
}
/*
* 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 = is_dev_possibly_bootable(-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");
}
void main(void)
{
sclp_setup();
css_setup();
boot_setup();
if (have_iplb) {
find_boot_device();
ipl_boot_device();
} else {
probe_boot_device();
}
panic("Failed to load OS from hard disk\n");
}