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_str[LOADPARM_LEN + 1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
  19 QemuIplParameters qipl;
  20
  21 #define LOADPARM_PROMPT "PROMPT  "
  22 #define LOADPARM_EMPTY  "        "
  23 #define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL)
  24
  25 /*
  26  * Priniciples of Operations (SA22-7832-09) chapter 17 requires that
  27  * a subsystem-identification is at 184-187 and bytes 188-191 are zero
  28  * after list-directed-IPL and ccw-IPL.
  29  */
  30 void write_subsystem_identification(void)
  31 {
  32     SubChannelId *schid = (SubChannelId *) 184;
  33     uint32_t *zeroes = (uint32_t *) 188;
  34
  35     *schid = blk_schid;
  36     *zeroes = 0;
  37 }
  38
  39 void panic(const char *string)
  40 {
  41     sclp_print(string);
  42     disabled_wait();
  43     while (1) { }
  44 }
  45
  46 unsigned int get_loadparm_index(void)
  47 {
  48     return atoui(loadparm_str);
  49 }
  50
  51 static bool find_dev(Schib *schib, int dev_no)
  52 {
  53     int i, r;
  54
  55     for (i = 0; i < 0x10000; i++) {
  56         blk_schid.sch_no = i;
  57         r = stsch_err(blk_schid, schib);
  58         if ((r == 3) || (r == -EIO)) {
  59             break;
  60         }
  61         if (!schib->pmcw.dnv) {
  62             continue;
  63         }
  64         if (!virtio_is_supported(blk_schid)) {
  65             continue;
  66         }
  67         /* Skip net devices since no IPLB is created and therefore no
  68          * no network bootloader has been loaded
  69          */
  70         if (virtio_get_device_type() == VIRTIO_ID_NET && dev_no < 0) {
  71             continue;
  72         }
  73         if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) {
  74             return true;
  75         }
  76     }
  77
  78     return false;
  79 }
  80
  81 static void menu_setup(void)
  82 {
  83     if (memcmp(loadparm_str, LOADPARM_PROMPT, LOADPARM_LEN) == 0) {
  84         menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
  85         return;
  86     }
  87
  88     /* If loadparm was set to any other value, then do not enable menu */
  89     if (memcmp(loadparm_str, LOADPARM_EMPTY, LOADPARM_LEN) != 0) {
  90         return;
  91     }
  92
  93     switch (iplb.pbt) {
  94     case S390_IPL_TYPE_CCW:
  95     case S390_IPL_TYPE_QEMU_SCSI:
  96         menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK,
  97                        qipl.boot_menu_timeout);
  98         return;
  99     }
 100 }
 101
 102 /*
 103  * Initialize the channel I/O subsystem so we can talk to our ipl/boot device.
 104  */
 105 static void css_setup(void)
 106 {
 107     /*
 108      * Unconditionally enable mss support. In every sane configuration this
 109      * will succeed; and even if it doesn't, stsch_err() can handle it.
 110      */
 111     enable_mss_facility();
 112 }
 113
 114 static void virtio_setup(void)
 115 {
 116     Schib schib;
 117     int ssid;
 118     bool found = false;
 119     uint16_t dev_no;
 120     char ldp[] = "LOADPARM=[________]\n";
 121     VDev *vdev = virtio_get_device();
 122     QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;
 123
 124     sclp_get_loadparm_ascii(loadparm_str);
 125     memcpy(ldp + 10, loadparm_str, LOADPARM_LEN);
 126     sclp_print(ldp);
 127
 128     memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));
 129
 130     if (store_iplb(&iplb)) {
 131         switch (iplb.pbt) {
 132         case S390_IPL_TYPE_CCW:
 133             dev_no = iplb.ccw.devno;
 134             debug_print_int("device no. ", dev_no);
 135             blk_schid.ssid = iplb.ccw.ssid & 0x3;
 136             debug_print_int("ssid ", blk_schid.ssid);
 137             found = find_dev(&schib, dev_no);
 138             break;
 139         case S390_IPL_TYPE_QEMU_SCSI:
 140             vdev->scsi_device_selected = true;
 141             vdev->selected_scsi_device.channel = iplb.scsi.channel;
 142             vdev->selected_scsi_device.target = iplb.scsi.target;
 143             vdev->selected_scsi_device.lun = iplb.scsi.lun;
 144             blk_schid.ssid = iplb.scsi.ssid & 0x3;
 145             found = find_dev(&schib, iplb.scsi.devno);
 146             break;
 147         default:
 148             panic("List-directed IPL not supported yet!\n");
 149         }
 150         menu_setup();
 151     } else {
 152         for (ssid = 0; ssid < 0x3; ssid++) {
 153             blk_schid.ssid = ssid;
 154             found = find_dev(&schib, -1);
 155             if (found) {
 156                 break;
 157             }
 158         }
 159     }
 160
 161     IPL_assert(found, "No virtio device found");
 162
 163     if (virtio_get_device_type() == VIRTIO_ID_NET) {
 164         sclp_print("Network boot device detected\n");
 165         vdev->netboot_start_addr = qipl.netboot_start_addr;
 166     } else {
 167         virtio_blk_setup_device(blk_schid);
 168
 169         IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
 170     }
 171 }
 172
 173 int main(void)
 174 {
 175     sclp_setup();
 176     css_setup();
 177     virtio_setup();
 178
 179     zipl_load(); /* no return */
 180
 181     panic("Failed to load OS from hard disk\n");
 182     return 0; /* make compiler happy */
 183 }