9f4278837d
We are already using the libc from SLOF for the s390-netboot.img, and
this libc implementation is way more complete and accurate than the
simple implementation that we currently use for the s390-ccw.img binary.
Since we are now always assuming that the SLOF submodule is available
when building the s390-ccw bios (see commit bf6903f694), we can drop
the simple implementation and use the SLOF libc for the s390-ccw.img
binary, too.
Additionally replace sclp_print calls with puts/printf now that it is
available.
Co-authored by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
Message-ID: <20241020012953.1380075-3-jrossi@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
99 lines
2.8 KiB
C
99 lines
2.8 KiB
C
/*
|
|
* QEMU s390-ccw firmware - jump to IPL code
|
|
*
|
|
* 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 <string.h>
|
|
#include <stdio.h>
|
|
#include "s390-ccw.h"
|
|
#include "s390-arch.h"
|
|
|
|
#define KERN_IMAGE_START 0x010000UL
|
|
#define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
|
|
#define RESET_PSW ((uint64_t)&jump_to_IPL_addr | RESET_PSW_MASK)
|
|
|
|
static uint64_t *reset_psw = 0, save_psw, ipl_continue;
|
|
|
|
void write_reset_psw(uint64_t psw)
|
|
{
|
|
*reset_psw = psw;
|
|
}
|
|
|
|
static void jump_to_IPL_addr(void)
|
|
{
|
|
__attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
|
|
|
|
/* Restore reset PSW */
|
|
write_reset_psw(save_psw);
|
|
|
|
ipl();
|
|
/* should not return */
|
|
}
|
|
|
|
void jump_to_IPL_code(uint64_t address)
|
|
{
|
|
/* store the subsystem information _after_ the bootmap was loaded */
|
|
write_subsystem_identification();
|
|
write_iplb_location();
|
|
|
|
/* prevent unknown IPL types in the guest */
|
|
if (iplb.pbt == S390_IPL_TYPE_QEMU_SCSI) {
|
|
iplb.pbt = S390_IPL_TYPE_CCW;
|
|
set_iplb(&iplb);
|
|
}
|
|
|
|
/*
|
|
* The IPL PSW is at address 0. We also must not overwrite the
|
|
* content of non-BIOS memory after we loaded the guest, so we
|
|
* save the original content and restore it in jump_to_IPL_2.
|
|
*/
|
|
if (address) {
|
|
save_psw = *reset_psw;
|
|
write_reset_psw(RESET_PSW);
|
|
ipl_continue = address;
|
|
}
|
|
debug_print_int("set IPL addr to", address ?: *reset_psw & PSW_MASK_SHORT_ADDR);
|
|
|
|
/* Ensure the guest output starts fresh */
|
|
printf("\n");
|
|
|
|
/*
|
|
* HACK ALERT.
|
|
* We use the load normal reset to keep r15 unchanged. jump_to_IPL_2
|
|
* can then use r15 as its stack pointer.
|
|
*/
|
|
asm volatile("lghi %%r1,1\n\t"
|
|
"diag %%r1,%%r1,0x308\n\t"
|
|
: : : "1", "memory");
|
|
panic("\n! IPL returns !\n");
|
|
}
|
|
|
|
void jump_to_low_kernel(void)
|
|
{
|
|
/*
|
|
* If it looks like a Linux binary, i.e. there is the "S390EP" magic from
|
|
* arch/s390/kernel/head.S here, then let's jump to the well-known Linux
|
|
* kernel start address (when jumping to the PSW-at-zero address instead,
|
|
* the kernel startup code fails when we booted from a network device).
|
|
*/
|
|
if (!memcmp((char *)S390EP, "S390EP", 6)) {
|
|
jump_to_IPL_code(KERN_IMAGE_START);
|
|
}
|
|
|
|
/* Trying to get PSW at zero address (pointed to by reset_psw) */
|
|
if (*reset_psw & RESET_PSW_MASK) {
|
|
/*
|
|
* Surely nobody will try running directly from lowcore, so
|
|
* let's use 0 as an indication that we want to load the reset
|
|
* psw at 0x0 and not jump to the entry.
|
|
*/
|
|
jump_to_IPL_code(0);
|
|
}
|
|
|
|
/* No other option left, so use the Linux kernel start address */
|
|
jump_to_IPL_code(KERN_IMAGE_START);
|
|
}
|