pc-bios/s390-ccw/main.c

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