diff options
Diffstat (limited to 'pc-bios/s390-ccw/main.c')
| -rw-r--r-- | pc-bios/s390-ccw/main.c | 17 |
1 files changed, 16 insertions, 1 deletions
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; |