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 "libc.h" 12 #include "s390-ccw.h" 13 #include "virtio.h" 14 15 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); 16 static SubChannelId blk_schid = { .one = 1 }; 17 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE))); 18 static char loadparm[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; 19 20 /* 21 * Priniciples of Operations (SA22-7832-09) chapter 17 requires that 22 * a subsystem-identification is at 184-187 and bytes 188-191 are zero 23 * after list-directed-IPL and ccw-IPL. 24 */ 25 void write_subsystem_identification(void) 26 { 27 SubChannelId *schid = (SubChannelId *) 184; 28 uint32_t *zeroes = (uint32_t *) 188; 29 30 *schid = blk_schid; 31 *zeroes = 0; 32 } 33 34 void panic(const char *string) 35 { 36 sclp_print(string); 37 disabled_wait(); 38 while (1) { } 39 } 40 41 unsigned int get_loadparm_index(void) 42 { 43 const char *lp = loadparm; 44 int i; 45 unsigned int idx = 0; 46 47 for (i = 0; i < 8; i++) { 48 char c = lp[i]; 49 50 if (c < '0' || c > '9') { 51 break; 52 } 53 54 idx *= 10; 55 idx += c - '0'; 56 } 57 58 return idx; 59 } 60 61 static bool find_dev(Schib *schib, int dev_no) 62 { 63 int i, r; 64 65 for (i = 0; i < 0x10000; i++) { 66 blk_schid.sch_no = i; 67 r = stsch_err(blk_schid, schib); 68 if ((r == 3) || (r == -EIO)) { 69 break; 70 } 71 if (!schib->pmcw.dnv) { 72 continue; 73 } 74 if (!virtio_is_supported(blk_schid)) { 75 continue; 76 } 77 /* Skip net devices since no IPLB is created and therefore no 78 * no network bootloader has been loaded 79 */ 80 if (virtio_get_device_type() == VIRTIO_ID_NET && dev_no < 0) { 81 continue; 82 } 83 if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) { 84 return true; 85 } 86 } 87 88 return false; 89 } 90 91 static void virtio_setup(void) 92 { 93 Schib schib; 94 int ssid; 95 bool found = false; 96 uint16_t dev_no; 97 char ldp[] = "LOADPARM=[________]\n"; 98 VDev *vdev = virtio_get_device(); 99 100 /* 101 * We unconditionally enable mss support. In every sane configuration, 102 * this will succeed; and even if it doesn't, stsch_err() can deal 103 * with the consequences. 104 */ 105 enable_mss_facility(); 106 107 sclp_get_loadparm_ascii(loadparm); 108 memcpy(ldp + 10, loadparm, 8); 109 sclp_print(ldp); 110 111 if (store_iplb(&iplb)) { 112 switch (iplb.pbt) { 113 case S390_IPL_TYPE_CCW: 114 dev_no = iplb.ccw.devno; 115 debug_print_int("device no. ", dev_no); 116 blk_schid.ssid = iplb.ccw.ssid & 0x3; 117 debug_print_int("ssid ", blk_schid.ssid); 118 found = find_dev(&schib, dev_no); 119 break; 120 case S390_IPL_TYPE_QEMU_SCSI: 121 vdev->scsi_device_selected = true; 122 vdev->selected_scsi_device.channel = iplb.scsi.channel; 123 vdev->selected_scsi_device.target = iplb.scsi.target; 124 vdev->selected_scsi_device.lun = iplb.scsi.lun; 125 blk_schid.ssid = iplb.scsi.ssid & 0x3; 126 found = find_dev(&schib, iplb.scsi.devno); 127 break; 128 default: 129 panic("List-directed IPL not supported yet!\n"); 130 } 131 } else { 132 for (ssid = 0; ssid < 0x3; ssid++) { 133 blk_schid.ssid = ssid; 134 found = find_dev(&schib, -1); 135 if (found) { 136 break; 137 } 138 } 139 } 140 141 IPL_assert(found, "No virtio device found"); 142 143 if (virtio_get_device_type() == VIRTIO_ID_NET) { 144 sclp_print("Network boot device detected\n"); 145 vdev->netboot_start_addr = iplb.ccw.netboot_start_addr; 146 } else { 147 virtio_blk_setup_device(blk_schid); 148 149 IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected"); 150 } 151 } 152 153 int main(void) 154 { 155 sclp_setup(); 156 virtio_setup(); 157 158 zipl_load(); /* no return */ 159 160 panic("Failed to load OS from hard disk\n"); 161 return 0; /* make compiler happy */ 162 } 163