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
  13 struct subchannel_id blk_schid;
  14 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
  15 uint64_t boot_value;
  16
  17 void virtio_panic(const char *string)
  18 {
  19     sclp_print(string);
  20     disabled_wait();
  21     while (1) { }
  22 }
  23
  24 static void virtio_setup(uint64_t dev_info)
  25 {
  26     struct schib schib;
  27     int i;
  28     int r;
  29     bool found = false;
  30     bool check_devno = false;
  31     uint16_t dev_no = -1;
  32     blk_schid.one = 1;
  33
  34     if (dev_info != -1) {
  35         check_devno = true;
  36         dev_no = dev_info & 0xffff;
  37         debug_print_int("device no. ", dev_no);
  38         blk_schid.ssid = (dev_info >> 16) & 0x3;
  39         if (blk_schid.ssid != 0) {
  40             debug_print_int("ssid ", blk_schid.ssid);
  41             if (enable_mss_facility() != 0) {
  42                 virtio_panic("Failed to enable mss facility\n");
  43             }
  44         }
  45     }
  46
  47     for (i = 0; i < 0x10000; i++) {
  48         blk_schid.sch_no = i;
  49         r = stsch_err(blk_schid, &schib);
  50         if (r == 3) {
  51             break;
  52         }
  53         if (schib.pmcw.dnv) {
  54             if (!check_devno || (schib.pmcw.dev == dev_no)) {
  55                 if (virtio_is_blk(blk_schid)) {
  56                     found = true;
  57                     break;
  58                 }
  59             }
  60         }
  61     }
  62
  63     if (!found) {
  64         virtio_panic("No virtio-blk device found!\n");
  65     }
  66
  67     virtio_setup_block(blk_schid);
  68 }
  69
  70 int main(void)
  71 {
  72     sclp_setup();
  73     debug_print_int("boot reg[7] ", boot_value);
  74     virtio_setup(boot_value);
  75
  76     if (zipl_load() < 0)
  77         sclp_print("Failed to load OS from hard disk\n");
  78     disabled_wait();
  79     while (1) { }
  80 }