/*-
 * Copyright (c) 1998 Robert Nordier
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are freely
 * permitted provided that the above copyright notice and this
 * paragraph and the following disclaimer are duplicated in all
 * such forms.
 *
 * This software is provided "AS IS" and without any express or
 * implied warranties, including, without limitation, the implied
 * warranties of merchantability and fitness for a particular
 * purpose.
 */

#include <sys/param.h>
#include <sys/disklabel.h>
#include <sys/diskmbr.h>
#include <sys/dirent.h>
#include <sys/reboot.h>

#include <machine/bootinfo.h>
#include <machine/elf.h>

#include <stdarg.h>

#include <a.out.h>

#include <btxv86.h>

#include "boot2.h"
#include "lib.h"
#include "paths.h"
#include "rbx.h"

/* Define to 0 to omit serial support */
#ifndef SERIAL
#define SERIAL 1
#endif

#define IO_KEYBOARD     1
#define IO_SERIAL       2

#if SERIAL
#define DO_KBD (ioctrl & IO_KEYBOARD)
#define DO_SIO (ioctrl & IO_SERIAL)
#else
#define DO_KBD (1)
#define DO_SIO (0)
#endif

#define SECOND          18      /* Circa that many ticks in a second. */

#define ARGS            0x900
#define NOPT            14
#define NDEV            3
#define MEM_BASE        0x12
#define MEM_EXT         0x15

#define DRV_HARD        0x80
#define DRV_MASK        0x7f

#define TYPE_AD         0
#define TYPE_DA         1
#define TYPE_MAXHARD    TYPE_DA
#define TYPE_FD         2

extern uint32_t _end;

static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
static const unsigned char flags[NOPT] = {
        RBX_DUAL,
        RBX_SERIAL,
        RBX_ASKNAME,
        RBX_CDROM,
        RBX_CONFIG,
        RBX_KDB,
        RBX_GDB,
        RBX_MUTE,
        RBX_NOINTR,
        RBX_PAUSE,
        RBX_QUIET,
        RBX_DFLTROOT,
        RBX_SINGLE,
        RBX_VERBOSE
};

static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
static const unsigned char dev_maj[NDEV] = {30, 4, 2};

static struct dsk {
        unsigned drive;
        unsigned type;
        unsigned unit;
        uint8_t slice;
        uint8_t part;
        unsigned start;
        int init;
} dsk;
static char cmd[512], cmddup[512], knamebuf[1024];
static const char *kname;
uint32_t opts;
static struct bootinfo bootinfo;
#if SERIAL
static int comspeed = SIOSPD;
static uint8_t ioctrl = IO_KEYBOARD;
#endif

int main(void);
void exit(int);
static void load(void);
static int parse(void);
static int dskread(void *, unsigned, unsigned);
static void printf(const char *,...);
static void putchar(int);
static int drvread(void *, unsigned, unsigned);
static int keyhit(unsigned);
static int xputc(int);
static int xgetc(int);
static inline int getc(int);

static void memcpy(void *, const void *, int);
static void
memcpy(void *dst, const void *src, int len)
{
        const char *s;
        char *d;

        s = src;
        d = dst;

        while (len--)
                *d++ = *s++;
}

static inline int
strcmp(const char *s1, const char *s2)
{

        for (; *s1 == *s2 && *s1; s1++, s2++);
        return ((unsigned char)*s1 - (unsigned char)*s2);
}

#define UFS_SMALL_CGBASE
#include "ufsread.c"

static int
xfsread(ufs_ino_t inode, void *buf, size_t nbyte)
{

        if ((size_t)fsread(inode, buf, nbyte) != nbyte) {
                printf("Invalid %s\n", "format");
                return (-1);
        }
        return (0);
}

static inline void
getstr(void)
{
        char *s;
        int c;

        s = cmd;
        for (;;) {
                switch (c = xgetc(0)) {
                case 0:
                        break;
                case '\177':
                case '\b':
                        if (s > cmd) {
                                s--;
                                printf("\b \b");
                        }
                        break;
                case '\n':
                case '\r':
                        *s = 0;
                        return;
                default:
                        if (s - cmd < sizeof(cmd) - 1)
                                *s++ = c;
                        putchar(c);
                }
        }
}

static inline void
putc(int c)
{

        v86.addr = 0x10;
        v86.eax = 0xe00 | (c & 0xff);
        v86.ebx = 0x7;
        v86int();
}

int
main(void)
{
        uint8_t autoboot;
        ufs_ino_t ino;
        size_t nbyte;

        dmadat = (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base);
        v86.ctl = V86_FLAGS;
        v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
        dsk.drive = *(uint8_t *)PTOV(ARGS);
        dsk.type = dsk.drive & DRV_HARD ? TYPE_AD : TYPE_FD;
        dsk.unit = dsk.drive & DRV_MASK;
        dsk.slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
        bootinfo.bi_version = BOOTINFO_VERSION;
        bootinfo.bi_size = sizeof(bootinfo);

        /* Process configuration file */

        autoboot = 1;

        if ((ino = lookup(PATH_CONFIG)) ||
            (ino = lookup(PATH_DOTCONFIG))) {
                nbyte = fsread(ino, cmd, sizeof(cmd) - 1);
                cmd[nbyte] = '\0';
        }

        if (*cmd) {
                memcpy(cmddup, cmd, sizeof(cmd));
                if (parse())
                        autoboot = 0;
                if (!OPT_CHECK(RBX_QUIET))
                        printf("%s: %s", PATH_CONFIG, cmddup);
                /* Do not process this command twice */
                *cmd = 0;
        }

        /*
         * Try to exec stage 3 boot loader. If interrupted by a keypress,
         * or in case of failure, try to load a kernel directly instead.
         */

        if (!kname) {
                kname = PATH_LOADER;
                if (autoboot && !keyhit(3*SECOND)) {
                        load();
                        kname = PATH_KERNEL;
                }
        }

        /* Present the user with the boot2 prompt. */

        for (;;) {
                if (!autoboot || !OPT_CHECK(RBX_QUIET))
                        printf("\nFreeBSD/x86 boot\n"
                                 "Default: %u:%s(%u,%c)%s\n"
                                 "boot: ",
                            dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
                            'a' + dsk.part, kname);
                if (DO_SIO)
                        sio_flush();
                if (!autoboot || keyhit(3*SECOND))
                        getstr();
                else if (!autoboot || !OPT_CHECK(RBX_QUIET))
                        putchar('\n');
                autoboot = 0;
                if (parse())
                        putchar('\a');
                else
                        load();
        }
}

/* XXX - Needed for btxld to link the boot2 binary; do not remove. */
void
exit(int x)
{

}

static void
load(void)
{
        union {
                struct exec ex;
                Elf32_Ehdr eh;
        } hdr;
        static Elf32_Phdr ep[2];
        static Elf32_Shdr es[2];
        caddr_t p;
        ufs_ino_t ino;
        uint32_t addr;
        int k;
        uint8_t i, j;

        if (!(ino = lookup(kname))) {
                if (!ls)
                        printf("No %s\n", kname);
                return;
        }
        if (xfsread(ino, &hdr, sizeof(hdr)))
                return;

        if (N_GETMAGIC(hdr.ex) == ZMAGIC) {
                addr = hdr.ex.a_entry & 0xffffff;
                p = PTOV(addr);
                fs_off = PAGE_SIZE;
                if (xfsread(ino, p, hdr.ex.a_text))
                        return;
                p += roundup2(hdr.ex.a_text, PAGE_SIZE);
                if (xfsread(ino, p, hdr.ex.a_data))
                        return;
        } else if (IS_ELF(hdr.eh)) {
                fs_off = hdr.eh.e_phoff;
                for (j = k = 0; k < hdr.eh.e_phnum && j < 2; k++) {
                        if (xfsread(ino, ep + j, sizeof(ep[0])))
                                return;
                        if (ep[j].p_type == PT_LOAD)
                                j++;
                }
                for (i = 0; i < 2; i++) {
                        p = PTOV(ep[i].p_paddr & 0xffffff);
                        fs_off = ep[i].p_offset;
                        if (xfsread(ino, p, ep[i].p_filesz))
                                return;
                }
                p += roundup2(ep[1].p_memsz, PAGE_SIZE);
                bootinfo.bi_symtab = VTOP(p);
                if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
                        fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
                            (hdr.eh.e_shstrndx + 1);
                        if (xfsread(ino, &es, sizeof(es)))
                                return;
                        for (i = 0; i < 2; i++) {
                                *(Elf32_Word *)p = es[i].sh_size;
                                p += sizeof(es[i].sh_size);
                                fs_off = es[i].sh_offset;
                                if (xfsread(ino, p, es[i].sh_size))
                                        return;
                                p += es[i].sh_size;
                        }
                }
                addr = hdr.eh.e_entry & 0xffffff;
                bootinfo.bi_esymtab = VTOP(p);
        } else {
                printf("Invalid %s\n", "format");
                return;
        }

        bootinfo.bi_kernelname = VTOP(kname);
        bootinfo.bi_bios_dev = dsk.drive;
        __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
            MAKEBOOTDEV(dev_maj[dsk.type], dsk.slice, dsk.unit, dsk.part),
            0, 0, 0, VTOP(&bootinfo));
}

static int
parse(void)
{
        char *arg, *ep, *p, *q;
        const char *cp;
        unsigned int drv;
        int c, i, j;
        size_t k;

        arg = cmd;

        while ((c = *arg++)) {
                if (c == ' ' || c == '\t' || c == '\n')
                        continue;
                for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
                ep = p;
                if (*p)
                        *p++ = 0;
                if (c == '-') {
                        while ((c = *arg++)) {
                                if (c == 'P') {
                                        if (*(uint8_t *)PTOV(0x496) & 0x10) {
                                                cp = "yes";
                                        } else {
                                                opts |= OPT_SET(RBX_DUAL) |
                                                    OPT_SET(RBX_SERIAL);
                                                cp = "no";
                                        }
                                        printf("Keyboard: %s\n", cp);
                                        continue;
#if SERIAL
                                } else if (c == 'S') {
                                        j = 0;
                                        while ((u_int)(i = *arg++ - '0') <= 9)
                                                j = j * 10 + i;
                                        if (j > 0 && i == -'0') {
                                                comspeed = j;
                                                break;
                                        }
                                        /*
                                         * Fall through to error below
                                         * ('S' not in optstr[]).
                                         */
#endif
                                }
                                for (i = 0; c != optstr[i]; i++)
                                        if (i == NOPT - 1)
                                                return (-1);
                                opts ^= OPT_SET(flags[i]);
                        }
#if SERIAL
                        ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
                            OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
                        if (DO_SIO) {
                                if (sio_init(115200 / comspeed) != 0)
                                        ioctrl &= ~IO_SERIAL;
                        }
#endif
                } else {
                        for (q = arg--; *q && *q != '('; q++);
                        if (*q) {
                                drv = -1;
                                if (arg[1] == ':') {
                                        drv = *arg - '0';
                                        if (drv > 9)
                                                return (-1);
                                        arg += 2;
                                }
                                if (q - arg != 2)
                                        return (-1);
                                for (i = 0; arg[0] != dev_nm[i][0] ||
                                    arg[1] != dev_nm[i][1]; i++)
                                        if (i == NDEV - 1)
                                                return (-1);
                                dsk.type = i;
                                arg += 3;
                                dsk.unit = *arg - '0';
                                if (arg[1] != ',' || dsk.unit > 9)
                                        return (-1);
                                arg += 2;
                                dsk.slice = WHOLE_DISK_SLICE;
                                if (arg[1] == ',') {
                                        dsk.slice = *arg - '0' + 1;
                                        if (dsk.slice > NDOSPART + 1)
                                                return (-1);
                                        arg += 2;
                                }
                                if (arg[1] != ')')
                                        return (-1);
                                dsk.part = *arg - 'a';
                                if (dsk.part > 7)
                                        return (-1);
                                arg += 2;
                                if (drv == -1)
                                        drv = dsk.unit;
                                dsk.drive = (dsk.type <= TYPE_MAXHARD
                                    ? DRV_HARD : 0) + drv;
                                dsk_meta = 0;
                        }
                        k = ep - arg;
                        if (k > 0) {
                                if (k >= sizeof(knamebuf))
                                        return (-1);
                                memcpy(knamebuf, arg, k + 1);
                                kname = knamebuf;
                        }
                }
                arg = p;
        }
        return (0);
}

static int
dskread(void *buf, unsigned lba, unsigned nblk)
{
        struct dos_partition *dp;
        struct disklabel *d;
        char *sec;
        unsigned i;
        uint8_t sl;
        const char *reason;

        if (!dsk_meta) {
                sec = dmadat->secbuf;
                dsk.start = 0;
                if (drvread(sec, DOSBBSECTOR, 1))
                        return (-1);
                dp = (void *)(sec + DOSPARTOFF);
                sl = dsk.slice;
                if (sl < BASE_SLICE) {
                        for (i = 0; i < NDOSPART; i++)
                                if (dp[i].dp_typ == DOSPTYP_386BSD &&
                                    (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
                                        sl = BASE_SLICE + i;
                                        if (dp[i].dp_flag & 0x80 ||
                                            dsk.slice == COMPATIBILITY_SLICE)
                                                break;
                                }
                        if (dsk.slice == WHOLE_DISK_SLICE)
                                dsk.slice = sl;
                }
                if (sl != WHOLE_DISK_SLICE) {
                        if (sl != COMPATIBILITY_SLICE)
                                dp += sl - BASE_SLICE;
                        if (dp->dp_typ != DOSPTYP_386BSD) {
                                reason = "slice";
                                goto error;
                        }
                        dsk.start = dp->dp_start;
                }
                if (drvread(sec, dsk.start + LABELSECTOR, 1))
                        return (-1);
                d = (void *)(sec + LABELOFFSET);
                if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
                        if (dsk.part != RAW_PART) {
                                reason = "label";
                                goto error;
                        }
                } else {
                        if (!dsk.init) {
                                if (d->d_type == DTYPE_SCSI)
                                        dsk.type = TYPE_DA;
                                dsk.init++;
                        }
                        if (dsk.part >= d->d_npartitions ||
                            !d->d_partitions[dsk.part].p_size) {
                                reason = "partition";
                                goto error;
                        }
                        dsk.start += d->d_partitions[dsk.part].p_offset;
                        dsk.start -= d->d_partitions[RAW_PART].p_offset;
                }
        }
        return (drvread(buf, dsk.start + lba, nblk));
error:
        printf("Invalid %s\n", reason);
        return (-1);
}

static void
printf(const char *fmt,...)
{
        va_list ap;
        static char buf[10];
        char *s;
        unsigned u;
        int c;

        va_start(ap, fmt);
        while ((c = *fmt++)) {
                if (c == '%') {
                        c = *fmt++;
                        switch (c) {
                        case 'c':
                                putchar(va_arg(ap, int));
                                continue;
                        case 's':
                                for (s = va_arg(ap, char *); *s; s++)
                                        putchar(*s);
                                continue;
                        case 'u':
                                u = va_arg(ap, unsigned);
                                s = buf;
                                do
                                        *s++ = '0' + u % 10U;
                                while (u /= 10U);
                                while (--s >= buf)
                                        putchar(*s);
                                continue;
                        }
                }
                putchar(c);
        }
        va_end(ap);
        return;
}

static void
putchar(int c)
{

        if (c == '\n')
                xputc('\r');
        xputc(c);
}

static int
drvread(void *buf, unsigned lba, unsigned nblk)
{
        static unsigned c = 0x2d5c7c2f;

        if (!OPT_CHECK(RBX_QUIET)) {
                xputc(c = c << 8 | c >> 24);
                xputc('\b');
        }
        v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
        v86.addr = XREADORG;            /* call to xread in boot1 */
        v86.es = VTOPSEG(buf);
        v86.eax = lba;
        v86.ebx = VTOPOFF(buf);
        v86.ecx = lba >> 16;
        v86.edx = nblk << 8 | dsk.drive;
        v86int();
        v86.ctl = V86_FLAGS;
        if (V86_CY(v86.efl)) {
                printf("error %u lba %u\n", v86.eax >> 8 & 0xff, lba);
                return (-1);
        }
        return (0);
}

static int
keyhit(unsigned ticks)
{
        uint32_t t0, t1;

        if (OPT_CHECK(RBX_NOINTR))
                return (0);
        t0 = 0;
        for (;;) {
                if (xgetc(1))
                        return (1);
                t1 = *(uint32_t *)PTOV(0x46c);
                if (!t0)
                        t0 = t1;
                if ((uint32_t)(t1 - t0) >= ticks)
                        return (0);
        }
}

static int
xputc(int c)
{

        if (DO_KBD)
                putc(c);
        if (DO_SIO)
                sio_putc(c);
        return (c);
}

static int
getc(int fn)
{

        v86.addr = 0x16;
        v86.eax = fn << 8;
        v86int();
        return (fn == 0 ? v86.eax & 0xff : !V86_ZR(v86.efl));
}

static int
xgetc(int fn)
{

        if (OPT_CHECK(RBX_NOINTR))
                return (0);
        for (;;) {
                if (DO_KBD && getc(1))
                        return (fn ? 1 : getc(0));
                if (DO_SIO && sio_ischar())
                        return (fn ? 1 : sio_getc());
                if (fn)
                        return (0);
        }
}