1 /* 2 * S390 virtio-ccw loading program 3 * 4 * Copyright (c) 2013 Alexander Graf <agraf@suse.de> 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or (at 7 * your option) any later version. See the COPYING file in the top-level 8 * directory. 9 */ 10 11 #include "s390-ccw.h" 12 #include "virtio.h" 13 14 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); 15 uint64_t boot_value; 16 struct subchannel_id blk_schid = { .one = 1 }; 17 18 /* 19 * Priniciples of Operations (SA22-7832-09) chapter 17 requires that 20 * a subsystem-identification is at 184-187 and bytes 188-191 are zero 21 * after list-directed-IPL and ccw-IPL. 22 */ 23 void write_subsystem_identification(void) 24 { 25 struct subchannel_id *schid = (struct subchannel_id *) 184; 26 uint32_t *zeroes = (uint32_t *) 188; 27 28 *schid = blk_schid; 29 *zeroes = 0; 30 } 31 32 33 void virtio_panic(const char *string) 34 { 35 sclp_print(string); 36 disabled_wait(); 37 while (1) { } 38 } 39 40 static void virtio_setup(uint64_t dev_info) 41 { 42 struct schib schib; 43 int i; 44 int r; 45 bool found = false; 46 bool check_devno = false; 47 uint16_t dev_no = -1; 48 49 if (dev_info != -1) { 50 check_devno = true; 51 dev_no = dev_info & 0xffff; 52 debug_print_int("device no. ", dev_no); 53 blk_schid.ssid = (dev_info >> 16) & 0x3; 54 if (blk_schid.ssid != 0) { 55 debug_print_int("ssid ", blk_schid.ssid); 56 if (enable_mss_facility() != 0) { 57 virtio_panic("Failed to enable mss facility\n"); 58 } 59 } 60 } 61 62 for (i = 0; i < 0x10000; i++) { 63 blk_schid.sch_no = i; 64 r = stsch_err(blk_schid, &schib); 65 if (r == 3) { 66 break; 67 } 68 if (schib.pmcw.dnv) { 69 if (!check_devno || (schib.pmcw.dev == dev_no)) { 70 if (virtio_is_blk(blk_schid)) { 71 found = true; 72 break; 73 } 74 } 75 } 76 } 77 78 if (!found) { 79 virtio_panic("No virtio-blk device found!\n"); 80 } 81 82 virtio_setup_block(blk_schid); 83 84 if (!virtio_ipl_disk_is_valid()) { 85 virtio_panic("No valid hard disk detected.\n"); 86 } 87 } 88 89 int main(void) 90 { 91 sclp_setup(); 92 debug_print_int("boot reg[7] ", boot_value); 93 virtio_setup(boot_value); 94 95 zipl_load(); /* no return */ 96 97 virtio_panic("Failed to load OS from hard disk\n"); 98 return 0; /* make compiler happy */ 99 } 100