/*-
 * 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/gpt.h>
#include <sys/dirent.h>
#include <sys/reboot.h>

#include <machine/bootinfo.h>
#include <machine/elf.h>
#include <machine/pc/bios.h>
#include <machine/psl.h>

#include <stdarg.h>

#include <a.out.h>

#include <btxv86.h>

#include "stand.h"

#include "bootargs.h"
#include "lib.h"
#include "rbx.h"
#include "drv.h"
#include "cons.h"
#include "gpt.h"
#include "paths.h"

#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
};
uint32_t opts;

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

static struct dsk dsk;
static char kname[1024];
static int comspeed = SIOSPD;
static struct bootinfo bootinfo;

static vm_offset_t      high_heap_base;
static uint32_t         bios_basemem, bios_extmem, high_heap_size;

static struct bios_smap smap;

/*
 * The minimum amount of memory to reserve in bios_extmem for the heap.
 */
#define HEAP_MIN        (3 * 1024 * 1024)

static char *heap_next;
static char *heap_end;

int main(void);

static void load(void);
static int parse_cmds(char *, int *);

static uint8_t ls, dsk_meta;
static uint32_t fs_off;

#include "cd9660read.c"

static inline int
xfsread(uint64_t inode, void *buf, size_t nbyte)
{

        if ((size_t)cd9660_fsread(inode, buf, nbyte) != nbyte) {
                printf("Invalid %s\n", "format");
                return (-1);
        }
        return (0);
}

static void
bios_getmem(void)
{
        uint64_t size;

        /* Parse system memory map */
        v86.ebx = 0;
        do {
                v86.ctl = V86_FLAGS;
                v86.addr = MEM_EXT;             /* int 0x15 function 0xe820*/
                v86.eax = 0xe820;
                v86.ecx = sizeof(struct bios_smap);
                v86.edx = SMAP_SIG;
                v86.es = VTOPSEG(&smap);
                v86.edi = VTOPOFF(&smap);
                v86int();
                if ((v86.efl & 1) || (v86.eax != SMAP_SIG))
                        break;
                /* look for a low-memory segment that's large enough */
                if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0) &&
                    (smap.length >= (512 * 1024)))
                        bios_basemem = smap.length;
                /* look for the first segment in 'extended' memory */
                if ((smap.type == SMAP_TYPE_MEMORY) &&
                    (smap.base == 0x100000)) {
                        bios_extmem = smap.length;
                }

                /*
                 * Look for the largest segment in 'extended' memory beyond
                 * 1MB but below 4GB.
                 */
                if ((smap.type == SMAP_TYPE_MEMORY) &&
                    (smap.base > 0x100000) && (smap.base < 0x100000000ull)) {
                        size = smap.length;

                        /*
                         * If this segment crosses the 4GB boundary,
                         * truncate it.
                         */
                        if (smap.base + size > 0x100000000ull)
                                size = 0x100000000ull - smap.base;

                        if (size > high_heap_size) {
                                high_heap_size = size;
                                high_heap_base = smap.base;
                        }
                }
        } while (v86.ebx != 0);

        /* Fall back to the old compatibility function for base memory */
        if (bios_basemem == 0) {
                v86.ctl = 0;
                v86.addr = 0x12;                /* int 0x12 */
                v86int();

                bios_basemem = (v86.eax & 0xffff) * 1024;
        }

        /*
         * Fall back through several compatibility functions for extended
         * memory
         */
        if (bios_extmem == 0) {
                v86.ctl = V86_FLAGS;
                v86.addr = 0x15;                /* int 0x15 function 0xe801*/
                v86.eax = 0xe801;
                v86int();
                if (!(v86.efl & 1)) {
                        bios_extmem = ((v86.ecx & 0xffff) +
                            ((v86.edx & 0xffff) * 64)) * 1024;
                }
        }
        if (bios_extmem == 0) {
                v86.ctl = 0;
                v86.addr = 0x15;                /* int 0x15 function 0x88*/
                v86.eax = 0x8800;
                v86int();
                bios_extmem = (v86.eax & 0xffff) * 1024;
        }

        /*
         * If we have extended memory and did not find a suitable heap
         * region in the SMAP, use the last 3MB of 'extended' memory as a
         * high heap candidate.
         */
        if (bios_extmem >= HEAP_MIN && high_heap_size < HEAP_MIN) {
                high_heap_size = HEAP_MIN;
                high_heap_base = bios_extmem + 0x100000 - HEAP_MIN;
        }
}

int
main(void)
{
        char cmd[512], cmdtmp[512];
        ssize_t sz;
        int autoboot, dskupdated;
        uint64_t ino;

        bios_getmem();

        if (high_heap_size > 0) {
                heap_end = PTOV(high_heap_base + high_heap_size);
                heap_next = PTOV(high_heap_base);
        } else {
                heap_next = (char *)
                    (roundup2(__base + (int32_t)&_end, 0x10000) - __base);
                heap_end = (char *)PTOV(bios_basemem);
        }
        setheap(heap_next, heap_end);

        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.part = -1;
        dsk.start = 0;
        bootinfo.bi_version = BOOTINFO_VERSION;
        bootinfo.bi_size = sizeof(bootinfo);
        bootinfo.bi_basemem = bios_basemem / 1024;
        bootinfo.bi_extmem = bios_extmem / 1024;
        bootinfo.bi_memsizes_valid++;
        bootinfo.bi_bios_dev = dsk.drive;

        autoboot = 1;
        *cmd = '\0';

        for (;;) {
                *kname = '\0';
                if ((ino = cd9660_lookup(PATH_CONFIG)) ||
                    (ino = cd9660_lookup(PATH_DOTCONFIG))) {
                        sz = cd9660_fsread(ino, cmd, sizeof(cmd) - 1);
                        cmd[(sz < 0) ? 0 : sz] = '\0';
                }
                if (*cmd != '\0') {
                        memcpy(cmdtmp, cmd, sizeof(cmdtmp));
                        if (parse_cmds(cmdtmp, &dskupdated))
                                break;
                        if (!OPT_CHECK(RBX_QUIET))
                                printf("%s: %s", PATH_CONFIG, cmd);
                        *cmd = '\0';
                }

                if (autoboot && keyhit(3)) {
                        if (*kname == '\0')
                                memcpy(kname, PATH_LOADER, sizeof(PATH_LOADER));
                        break;
                }
                autoboot = 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 != '\0')
                        load();
                memcpy(kname, PATH_LOADER, sizeof(PATH_LOADER));
                load();
                memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
                load();
                dsk_meta = 0;
        }

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

        for (;;) {
                if (!OPT_CHECK(RBX_QUIET)) {
                        printf("\nFreeBSD/x86 boot\n"
                            "Default: %u:%s(%up%u)%s\n"
                            "boot: ",
                            dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
                            dsk.part, kname);
                }
                if (ioctrl & IO_SERIAL)
                        sio_flush();
                *cmd = '\0';
                if (keyhit(0))
                        getstr(cmd, sizeof(cmd));
                else if (!OPT_CHECK(RBX_QUIET))
                        putchar('\n');
                if (parse_cmds(cmd, &dskupdated)) {
                        putchar('\a');
                        continue;
                }
                load();
        }
        /* NOTREACHED */
}

/* Needed so btxld can link us properly; do not remove. */
void
exit(int x)
{

        while (1);
        __unreachable();
}

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;
        uint64_t ino;
        uint32_t addr, x;
        int fmt, i, j;

        if (!(ino = cd9660_lookup(kname))) {
                if (!ls) {
                        printf("%s: No %s on %u:%s(%up%u)\n", BOOTPROG,
                            kname, dsk.drive & DRV_MASK, dev_nm[dsk.type],
                            dsk.unit,
                            dsk.part);
                }
                return;
        }
        if (xfsread(ino, &hdr, sizeof(hdr)))
                return;
        if (N_GETMAGIC(hdr.ex) == ZMAGIC)
                fmt = 0;
        else if (IS_ELF(hdr.eh))
                fmt = 1;
        else {
                printf("Invalid %s\n", "format");
                return;
        }
        if (fmt == 0) {
                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;
                p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
                bootinfo.bi_symtab = VTOP(p);
                memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
                p += sizeof(hdr.ex.a_syms);
                if (hdr.ex.a_syms) {
                        if (xfsread(ino, p, hdr.ex.a_syms))
                                return;
                        p += hdr.ex.a_syms;
                        if (xfsread(ino, p, sizeof(int)))
                                return;
                        x = *(uint32_t *)p;
                        p += sizeof(int);
                        x -= sizeof(int);
                        if (xfsread(ino, p, x))
                                return;
                        p += x;
                }
        } else {
                fs_off = hdr.eh.e_phoff;
                for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
                        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++) {
                                memcpy(p, &es[i].sh_size,
                                    sizeof(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);
        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], 0, dsk.unit, 0),
            0, 0, 0, VTOP(&bootinfo));
}

static int
parse_cmds(char *cmdstr, int *dskupdated)
{
        char *arg;
        char *ep, *p, *q;
        const char *cp;
        unsigned int drv;
        int c, i, j;

        arg = cmdstr;
        *dskupdated = 0;
        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;
                                } else if (c == 'S') {
                                        j = 0;
                                        while ((unsigned 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[]).
                                         */
                                }
                                for (i = 0; c != optstr[i]; i++)
                                        if (i == NOPT - 1)
                                                return (-1);
                                opts ^= OPT_SET(flags[i]);
                        }
                        ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
                            OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
                        if (ioctrl & IO_SERIAL) {
                                if (sio_init(115200 / comspeed) != 0)
                                        ioctrl &= ~IO_SERIAL;
                        }
                } 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] != 'p' || dsk.unit > 9)
                                        return (-1);
                                arg += 2;
                                dsk.part = *arg - '0';
                                if (dsk.part < 1 || dsk.part > 9)
                                        return (-1);
                                arg++;
                                if (arg[0] != ')')
                                        return (-1);
                                arg++;
                                if (drv == -1)
                                        drv = dsk.unit;
                                dsk.drive = (dsk.type <= TYPE_MAXHARD
                                    ? DRV_HARD : 0) + drv;
                                *dskupdated = 1;
                        }
                        if ((i = ep - arg)) {
                                if ((size_t)i >= sizeof(kname))
                                        return (-1);
                                memcpy(kname, arg, i + 1);
                        }
                }
                arg = p;
        }
        return (0);
}