summaryrefslogtreecommitdiff
path: root/pc-bios/s390-ccw/menu.c
blob: 96eec81e8429dd72a356709fa65175a9ece63a59 (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
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 * QEMU S390 Interactive Boot Menu
 *
 * Copyright 2018 IBM Corp.
 * Author: Collin L. Walling <walling@linux.vnet.ibm.com>
 *
 * 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 "sclp.h"

#define KEYCODE_NO_INP '\0'
#define KEYCODE_ESCAPE '\033'
#define KEYCODE_BACKSP '\177'
#define KEYCODE_ENTER  '\r'

/* Offsets from zipl fields to zipl banner start */
#define ZIPL_TIMEOUT_OFFSET 138
#define ZIPL_FLAG_OFFSET    140

#define TOD_CLOCK_MILLISECOND   0x3e8000

#define LOW_CORE_EXTERNAL_INT_ADDR   0x86
#define CLOCK_COMPARATOR_INT         0X1004

static uint8_t flag;
static uint64_t timeout;

static inline void enable_clock_int(void)
{
    uint64_t tmp = 0;

    asm volatile(
        "stctg      0,0,%0\n"
        "oi         6+%0, 0x8\n"
        "lctlg      0,0,%0"
        : : "Q" (tmp) : "memory"
    );
}

static inline void disable_clock_int(void)
{
    uint64_t tmp = 0;

    asm volatile(
        "stctg      0,0,%0\n"
        "ni         6+%0, 0xf7\n"
        "lctlg      0,0,%0"
        : : "Q" (tmp) : "memory"
    );
}

static inline void set_clock_comparator(uint64_t time)
{
    asm volatile("sckc %0" : : "Q" (time));
}

static inline bool check_clock_int(void)
{
    uint16_t *code = (uint16_t *)LOW_CORE_EXTERNAL_INT_ADDR;

    consume_sclp_int();

    return *code == CLOCK_COMPARATOR_INT;
}

static int read_prompt(char *buf, size_t len)
{
    char inp[2] = {};
    uint8_t idx = 0;
    uint64_t time;

    if (timeout) {
        time = get_clock() + timeout * TOD_CLOCK_MILLISECOND;
        set_clock_comparator(time);
        enable_clock_int();
        timeout = 0;
    }

    while (!check_clock_int()) {

        sclp_read(inp, 1); /* Process only one character at a time */

        switch (inp[0]) {
        case KEYCODE_NO_INP:
        case KEYCODE_ESCAPE:
            continue;
        case KEYCODE_BACKSP:
            if (idx > 0) {
                buf[--idx] = 0;
                sclp_print("\b \b");
            }
            continue;
        case KEYCODE_ENTER:
            disable_clock_int();
            return idx;
        default:
            /* Echo input and add to buffer */
            if (idx < len) {
                buf[idx++] = inp[0];
                sclp_print(inp);
            }
        }
    }

    disable_clock_int();
    *buf = 0;

    return 0;
}

static int get_index(void)
{
    char buf[11];
    int len;
    int i;

    memset(buf, 0, sizeof(buf));

    sclp_set_write_mask(SCLP_EVENT_MASK_MSG_ASCII, SCLP_EVENT_MASK_MSG_ASCII);

    len = read_prompt(buf, sizeof(buf) - 1);

    sclp_set_write_mask(0, SCLP_EVENT_MASK_MSG_ASCII);

    /* If no input, boot default */
    if (len == 0) {
        return 0;
    }

    /* Check for erroneous input */
    for (i = 0; i < len; i++) {
        if (!isdigit(buf[i])) {
            return -1;
        }
    }

    return atoui(buf);
}

static void boot_menu_prompt(bool retry)
{
    char tmp[11];

    if (retry) {
        sclp_print("\nError: undefined configuration"
                   "\nPlease choose:\n");
    } else if (timeout > 0) {
        sclp_print("Please choose (default will boot in ");
        sclp_print(uitoa(timeout / 1000, tmp, sizeof(tmp)));
        sclp_print(" seconds):\n");
    } else {
        sclp_print("Please choose:\n");
    }
}

static int get_boot_index(int entries)
{
    int boot_index;
    bool retry = false;
    char tmp[5];

    do {
        boot_menu_prompt(retry);
        boot_index = get_index();
        retry = true;
    } while (boot_index < 0 || boot_index >= entries);

    sclp_print("\nBooting entry #");
    sclp_print(uitoa(boot_index, tmp, sizeof(tmp)));

    return boot_index;
}

static void zipl_println(const char *data, size_t len)
{
    char buf[len + 2];

    ebcdic_to_ascii(data, buf, len);
    buf[len] = '\n';
    buf[len + 1] = '\0';

    sclp_print(buf);
}

int menu_get_zipl_boot_index(const char *menu_data)
{
    size_t len;
    int entries;
    uint16_t zipl_flag = *(uint16_t *)(menu_data - ZIPL_FLAG_OFFSET);
    uint16_t zipl_timeout = *(uint16_t *)(menu_data - ZIPL_TIMEOUT_OFFSET);

    if (flag == QIPL_FLAG_BM_OPTS_ZIPL) {
        if (!zipl_flag) {
            return 0; /* Boot default */
        }
        /* zipl stores timeout as seconds */
        timeout = zipl_timeout * 1000;
    }

    /* Print and count all menu items, including the banner */
    for (entries = 0; *menu_data; entries++) {
        len = strlen(menu_data);
        zipl_println(menu_data, len);
        menu_data += len + 1;

        if (entries < 2) {
            sclp_print("\n");
        }
    }

    sclp_print("\n");
    return get_boot_index(entries - 1); /* subtract 1 to exclude banner */
}


int menu_get_enum_boot_index(int entries)
{
    char tmp[4];

    sclp_print("s390x Enumerated Boot Menu.\n\n");

    sclp_print(uitoa(entries, tmp, sizeof(tmp)));
    sclp_print(" entries detected. Select from boot index 0 to ");
    sclp_print(uitoa(entries - 1, tmp, sizeof(tmp)));
    sclp_print(".\n\n");

    return get_boot_index(entries);
}

void menu_set_parms(uint8_t boot_menu_flag, uint32_t boot_menu_timeout)
{
    flag = boot_menu_flag;
    timeout = boot_menu_timeout;
}

bool menu_is_enabled_zipl(void)
{
    return flag & (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL);
}

bool menu_is_enabled_enum(void)
{
    return flag & QIPL_FLAG_BM_OPTS_CMD;
}