summaryrefslogtreecommitdiff
path: root/pc-bios/s390-ccw/main.c
blob: a7473b039772e79a8ac17d0523e572c26bfe010e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/*
 * S390 virtio-ccw loading program
 *
 * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or (at
 * your option) any later version. See the COPYING file in the top-level
 * directory.
 */

#include "libc.h"
#include "s390-ccw.h"
#include "virtio.h"

char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
static SubChannelId blk_schid = { .one = 1 };
IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
static char loadparm[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
QemuIplParameters qipl;

#define LOADPARM_PROMPT "PROMPT  "
#define LOADPARM_EMPTY  "........"
#define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL)

/*
 * Priniciples of Operations (SA22-7832-09) chapter 17 requires that
 * a subsystem-identification is at 184-187 and bytes 188-191 are zero
 * after list-directed-IPL and ccw-IPL.
 */
void write_subsystem_identification(void)
{
    SubChannelId *schid = (SubChannelId *) 184;
    uint32_t *zeroes = (uint32_t *) 188;

    *schid = blk_schid;
    *zeroes = 0;
}

void panic(const char *string)
{
    sclp_print(string);
    disabled_wait();
    while (1) { }
}

unsigned int get_loadparm_index(void)
{
    return atoui(loadparm);
}

static bool find_dev(Schib *schib, int dev_no)
{
    int i, r;

    for (i = 0; i < 0x10000; i++) {
        blk_schid.sch_no = i;
        r = stsch_err(blk_schid, schib);
        if ((r == 3) || (r == -EIO)) {
            break;
        }
        if (!schib->pmcw.dnv) {
            continue;
        }
        if (!virtio_is_supported(blk_schid)) {
            continue;
        }
        /* Skip net devices since no IPLB is created and therefore no
         * no network bootloader has been loaded
         */
        if (virtio_get_device_type() == VIRTIO_ID_NET && dev_no < 0) {
            continue;
        }
        if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) {
            return true;
        }
    }

    return false;
}

static void menu_setup(void)
{
    if (memcmp(loadparm, LOADPARM_PROMPT, 8) == 0) {
        menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
        return;
    }

    /* If loadparm was set to any other value, then do not enable menu */
    if (memcmp(loadparm, LOADPARM_EMPTY, 8) != 0) {
        return;
    }

    switch (iplb.pbt) {
    case S390_IPL_TYPE_CCW:
        menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK,
                       qipl.boot_menu_timeout);
        return;
    }
}

static void virtio_setup(void)
{
    Schib schib;
    int ssid;
    bool found = false;
    uint16_t dev_no;
    char ldp[] = "LOADPARM=[________]\n";
    VDev *vdev = virtio_get_device();
    QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;

    /*
     * We unconditionally enable mss support. In every sane configuration,
     * this will succeed; and even if it doesn't, stsch_err() can deal
     * with the consequences.
     */
    enable_mss_facility();

    sclp_get_loadparm_ascii(loadparm);
    memcpy(ldp + 10, loadparm, 8);
    sclp_print(ldp);

    memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));

    if (store_iplb(&iplb)) {
        switch (iplb.pbt) {
        case S390_IPL_TYPE_CCW:
            dev_no = iplb.ccw.devno;
            debug_print_int("device no. ", dev_no);
            blk_schid.ssid = iplb.ccw.ssid & 0x3;
            debug_print_int("ssid ", blk_schid.ssid);
            found = find_dev(&schib, dev_no);
            break;
        case S390_IPL_TYPE_QEMU_SCSI:
            vdev->scsi_device_selected = true;
            vdev->selected_scsi_device.channel = iplb.scsi.channel;
            vdev->selected_scsi_device.target = iplb.scsi.target;
            vdev->selected_scsi_device.lun = iplb.scsi.lun;
            blk_schid.ssid = iplb.scsi.ssid & 0x3;
            found = find_dev(&schib, iplb.scsi.devno);
            break;
        default:
            panic("List-directed IPL not supported yet!\n");
        }
        menu_setup();
    } else {
        for (ssid = 0; ssid < 0x3; ssid++) {
            blk_schid.ssid = ssid;
            found = find_dev(&schib, -1);
            if (found) {
                break;
            }
        }
    }

    IPL_assert(found, "No virtio device found");

    if (virtio_get_device_type() == VIRTIO_ID_NET) {
        sclp_print("Network boot device detected\n");
        vdev->netboot_start_addr = qipl.netboot_start_addr;
    } else {
        virtio_blk_setup_device(blk_schid);

        IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
    }
}

int main(void)
{
    sclp_setup();
    virtio_setup();

    zipl_load(); /* no return */

    panic("Failed to load OS from hard disk\n");
    return 0; /* make compiler happy */
}