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