diff options
Diffstat (limited to 'pc-bios/s390-ccw/jump2ipl.c')
| -rw-r--r-- | pc-bios/s390-ccw/jump2ipl.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c index b6aad32def..fbae45b03c 100644 --- a/pc-bios/s390-ccw/jump2ipl.c +++ b/pc-bios/s390-ccw/jump2ipl.c @@ -12,15 +12,21 @@ #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 */ - *reset_psw = save_psw; + write_reset_psw(save_psw); ipl(); /* should not return */ @@ -43,11 +49,12 @@ void jump_to_IPL_code(uint64_t address) * content of non-BIOS memory after we loaded the guest, so we * save the original content and restore it in jump_to_IPL_2. */ - save_psw = *reset_psw; - *reset_psw = (uint64_t) &jump_to_IPL_addr; - *reset_psw |= RESET_PSW_MASK; - ipl_continue = address; - debug_print_int("set IPL addr to", ipl_continue); + 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 */ sclp_print("\n"); @@ -77,7 +84,12 @@ void jump_to_low_kernel(void) /* Trying to get PSW at zero address */ if (*((uint64_t *)0) & RESET_PSW_MASK) { - jump_to_IPL_code((*((uint64_t *)0)) & PSW_MASK_SHORT_ADDR); + /* + * 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 */ |