diff options
| -rw-r--r-- | pc-bios/s390-ccw/bootmap.c | 2 | ||||
| -rw-r--r-- | pc-bios/s390-ccw/main.c | 17 | ||||
| -rw-r--r-- | pc-bios/s390-ccw/s390-ccw.h | 1 |
3 files changed, 19 insertions, 1 deletions
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c index fa54abb4d3..f1756796df 100644 --- a/pc-bios/s390-ccw/bootmap.c +++ b/pc-bios/s390-ccw/bootmap.c @@ -51,6 +51,8 @@ static void jump_to_IPL_2(void) static void jump_to_IPL_code(uint64_t address) { + /* store the subsystem information _after_ the bootmap was loaded */ + write_subsystem_identification(); /* * 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 diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c index dbfb40e685..f9ec2157ad 100644 --- a/pc-bios/s390-ccw/main.c +++ b/pc-bios/s390-ccw/main.c @@ -13,6 +13,22 @@ char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); uint64_t boot_value; +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) { @@ -23,7 +39,6 @@ void virtio_panic(const char *string) static void virtio_setup(uint64_t dev_info) { - struct subchannel_id blk_schid = { .one = 1 }; struct schib schib; int i; int r; diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h index 959aed0d0b..2b773deafa 100644 --- a/pc-bios/s390-ccw/s390-ccw.h +++ b/pc-bios/s390-ccw/s390-ccw.h @@ -50,6 +50,7 @@ void disabled_wait(void); /* main.c */ void virtio_panic(const char *string); +void write_subsystem_identification(void); /* sclp-ascii.c */ void sclp_print(const char *string); |