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 "s390-ccw.h"
  12 #include "virtio.h"
  13
  14 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
  15 static SubChannelId blk_schid = { .one = 1 };
  16 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
  17 static char loadparm[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  18
  19 const unsigned char ebc2asc[256] =
  20       /* 0123456789abcdef0123456789abcdef */
  21         "................................" /* 1F */
  22         "................................" /* 3F */
  23         " ...........<(+|&.........!$*);." /* 5F first.chr.here.is.real.space */
  24         "-/.........,%_>?.........`:#@'=\""/* 7F */
  25         ".abcdefghi.......jklmnopqr......" /* 9F */
  26         "..stuvwxyz......................" /* BF */
  27         ".ABCDEFGHI.......JKLMNOPQR......" /* DF */
  28         "..STUVWXYZ......0123456789......";/* FF */
  29
  30 /*
  31  * Priniciples of Operations (SA22-7832-09) chapter 17 requires that
  32  * a subsystem-identification is at 184-187 and bytes 188-191 are zero
  33  * after list-directed-IPL and ccw-IPL.
  34  */
  35 void write_subsystem_identification(void)
  36 {
  37     SubChannelId *schid = (SubChannelId *) 184;
  38     uint32_t *zeroes = (uint32_t *) 188;
  39
  40     *schid = blk_schid;
  41     *zeroes = 0;
  42 }
  43
  44 void panic(const char *string)
  45 {
  46     sclp_print(string);
  47     disabled_wait();
  48     while (1) { }
  49 }
  50
  51 unsigned int get_loadparm_index(void)
  52 {
  53     const char *lp = loadparm;
  54     int i;
  55     unsigned int idx = 0;
  56
  57     for (i = 0; i < 8; i++) {
  58         char c = lp[i];
  59
  60         if (c < '0' || c > '9') {
  61             break;
  62         }
  63
  64         idx *= 10;
  65         idx += c - '0';
  66     }
  67
  68     return idx;
  69 }
  70
  71 static bool find_dev(Schib *schib, int dev_no)
  72 {
  73     int i, r;
  74
  75     for (i = 0; i < 0x10000; i++) {
  76         blk_schid.sch_no = i;
  77         r = stsch_err(blk_schid, schib);
  78         if ((r == 3) || (r == -EIO)) {
  79             break;
  80         }
  81         if (!schib->pmcw.dnv) {
  82             continue;
  83         }
  84         if (!virtio_is_supported(blk_schid)) {
  85             continue;
  86         }
  87         /* Skip net devices since no IPLB is created and therefore no
  88          * no network bootloader has been loaded
  89          */
  90         if (virtio_get_device_type() == VIRTIO_ID_NET && dev_no < 0) {
  91             continue;
  92         }
  93         if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) {
  94             return true;
  95         }
  96     }
  97
  98     return false;
  99 }
 100
 101 static void virtio_setup(void)
 102 {
 103     Schib schib;
 104     int ssid;
 105     bool found = false;
 106     uint16_t dev_no;
 107     char ldp[] = "LOADPARM=[________]\n";
 108     VDev *vdev = virtio_get_device();
 109
 110     /*
 111      * We unconditionally enable mss support. In every sane configuration,
 112      * this will succeed; and even if it doesn't, stsch_err() can deal
 113      * with the consequences.
 114      */
 115     enable_mss_facility();
 116
 117     sclp_get_loadparm_ascii(loadparm);
 118     memcpy(ldp + 10, loadparm, 8);
 119     sclp_print(ldp);
 120
 121     if (store_iplb(&iplb)) {
 122         switch (iplb.pbt) {
 123         case S390_IPL_TYPE_CCW:
 124             dev_no = iplb.ccw.devno;
 125             debug_print_int("device no. ", dev_no);
 126             blk_schid.ssid = iplb.ccw.ssid & 0x3;
 127             debug_print_int("ssid ", blk_schid.ssid);
 128             found = find_dev(&schib, dev_no);
 129             break;
 130         case S390_IPL_TYPE_QEMU_SCSI:
 131             vdev->scsi_device_selected = true;
 132             vdev->selected_scsi_device.channel = iplb.scsi.channel;
 133             vdev->selected_scsi_device.target = iplb.scsi.target;
 134             vdev->selected_scsi_device.lun = iplb.scsi.lun;
 135             blk_schid.ssid = iplb.scsi.ssid & 0x3;
 136             found = find_dev(&schib, iplb.scsi.devno);
 137             break;
 138         default:
 139             panic("List-directed IPL not supported yet!\n");
 140         }
 141     } else {
 142         for (ssid = 0; ssid < 0x3; ssid++) {
 143             blk_schid.ssid = ssid;
 144             found = find_dev(&schib, -1);
 145             if (found) {
 146                 break;
 147             }
 148         }
 149     }
 150
 151     IPL_assert(found, "No virtio device found");
 152
 153     if (virtio_get_device_type() == VIRTIO_ID_NET) {
 154         sclp_print("Network boot device detected\n");
 155         vdev->netboot_start_addr = iplb.ccw.netboot_start_addr;
 156     } else {
 157         virtio_setup_device(blk_schid);
 158
 159         IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
 160     }
 161 }
 162
 163 int main(void)
 164 {
 165     sclp_setup();
 166     virtio_setup();
 167
 168     zipl_load(); /* no return */
 169
 170     panic("Failed to load OS from hard disk\n");
 171     return 0; /* make compiler happy */
 172 }