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 char ring_area[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); 16 uint64_t boot_value; 17 static struct subchannel_id blk_schid = { .one = 1 }; 18 19 /* 20 * Priniciples of Operations (SA22-7832-09) chapter 17 requires that 21 * a subsystem-identification is at 184-187 and bytes 188-191 are zero 22 * after list-directed-IPL and ccw-IPL. 23 */ 24 void write_subsystem_identification(void) 25 { 26 struct subchannel_id *schid = (struct subchannel_id *) 184; 27 uint32_t *zeroes = (uint32_t *) 188; 28 29 *schid = blk_schid; 30 *zeroes = 0; 31 } 32 33 34 void virtio_panic(const char *string) 35 { 36 sclp_print(string); 37 disabled_wait(); 38 while (1) { } 39 } 40 41 static void virtio_setup(uint64_t dev_info) 42 { 43 struct schib schib; 44 int i; 45 int r; 46 bool found = false; 47 bool check_devno = false; 48 uint16_t dev_no = -1; 49 50 if (dev_info != -1) { 51 check_devno = true; 52 dev_no = dev_info & 0xffff; 53 debug_print_int("device no. ", dev_no); 54 blk_schid.ssid = (dev_info >> 16) & 0x3; 55 if (blk_schid.ssid != 0) { 56 debug_print_int("ssid ", blk_schid.ssid); 57 if (enable_mss_facility() != 0) { 58 virtio_panic("Failed to enable mss facility\n"); 59 } 60 } 61 } 62 63 for (i = 0; i < 0x10000; i++) { 64 blk_schid.sch_no = i; 65 r = stsch_err(blk_schid, &schib); 66 if (r == 3) { 67 break; 68 } 69 if (schib.pmcw.dnv) { 70 if (!check_devno || (schib.pmcw.dev == dev_no)) { 71 if (virtio_is_blk(blk_schid)) { 72 found = true; 73 break; 74 } 75 } 76 } 77 } 78 79 if (!found) { 80 virtio_panic("No virtio-blk device found!\n"); 81 } 82 83 virtio_setup_block(blk_schid); 84 85 if (!virtio_ipl_disk_is_valid()) { 86 virtio_panic("No valid hard disk detected.\n"); 87 } 88 } 89 90 int main(void) 91 { 92 sclp_setup(); 93 debug_print_int("boot reg[7] ", boot_value); 94 virtio_setup(boot_value); 95 96 zipl_load(); /* no return */ 97 98 virtio_panic("Failed to load OS from hard disk\n"); 99 return 0; /* make compiler happy */ 100 } 101