ficl/emu/loader_emu.c

/*
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <limits.h>
#include <unistd.h>
#include <dirent.h>
#include <macros.h>
#include <sys/systeminfo.h>
#include <sys/queue.h>
#include <sys/mnttab.h>
#include "ficl.h"

/* Commands and return values; nonzero return sets command_errmsg != NULL */
typedef int (bootblk_cmd_t)(int argc, char *argv[]);
#define CMD_OK      0
#define CMD_ERROR   1

/*
 * Support for commands
 */
struct bootblk_command
{
    const char *c_name;
    const char *c_desc;
    bootblk_cmd_t *c_fn;
    STAILQ_ENTRY(bootblk_command) next;
};

#define MDIR_REMOVED    0x0001
#define MDIR_NOHINTS    0x0002

struct moduledir {
    char    *d_path;    /* path of modules directory */
    uchar_t *d_hints;   /* content of linker.hints file */
    int d_hintsz;   /* size of hints data */
    int d_flags;
    STAILQ_ENTRY(moduledir) d_link;
};
static STAILQ_HEAD(, moduledir) moduledir_list =
    STAILQ_HEAD_INITIALIZER(moduledir_list);

static const char *default_searchpath = "/platform/i86pc";

static char typestr[] = "?fc?d?b? ?l?s?w";
static int  ls_getdir(char **pathp);
extern char **_environ;

char    *command_errmsg;
char    command_errbuf[256];

extern void pager_open(void);
extern void pager_close(void);
extern int pager_output(const char *);
extern int pager_file(const char *);
static int page_file(char *);
static int include(const char *);

static int command_help(int argc, char *argv[]);
static int command_commandlist(int argc, char *argv[]);
static int command_show(int argc, char *argv[]);
static int command_set(int argc, char *argv[]);
static int command_setprop(int argc, char *argv[]);
static int command_unset(int argc, char *argv[]);
static int command_echo(int argc, char *argv[]);
static int command_read(int argc, char *argv[]);
static int command_more(int argc, char *argv[]);
static int command_ls(int argc, char *argv[]);
static int command_include(int argc, char *argv[]);
static int command_autoboot(int argc, char *argv[]);
static int command_boot(int argc, char *argv[]);
static int command_unload(int argc, char *argv[]);
static int command_load(int argc, char *argv[]);
static int command_reboot(int argc, char *argv[]);

#define BF_PARSE    100
#define BF_DICTSIZE 30000

/* update when loader version will change */
static const char bootprog_rev[] = "1.1";
STAILQ_HEAD(cmdh, bootblk_command) commands;

/*
 * BootForth   Interface to Ficl Forth interpreter.
 */

ficlSystem *bf_sys;
ficlVm  *bf_vm;

/*
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * Jordan K. Hubbard
 * 29 August 1998
 *
 * The meat of the simple parser.
 */

static void  clean(void);
static int   insert(int *argcp, char *buf);

#define PARSE_BUFSIZE   1024    /* maximum size of one element */
#define MAXARGS     20  /* maximum number of elements */
static  char        *args[MAXARGS];

#define DIGIT(x)    \
    (isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')

/*
 * backslash: Return malloc'd copy of str with all standard "backslash
 * processing" done on it.  Original can be free'd if desired.
 */
char *
backslash(char *str)
{
    /*
     * Remove backslashes from the strings. Turn \040 etc. into a single
     * character (we allow eight bit values). Currently NUL is not
     * allowed.
     *
     * Turn "\n" and "\t" into '\n' and '\t' characters. Etc.
     */
    char *new_str;
    int seenbs = 0;
    int i = 0;

    if ((new_str = strdup(str)) == NULL)
        return (NULL);

    while (*str) {
        if (seenbs) {
            seenbs = 0;
            switch (*str) {
            case '\\':
                new_str[i++] = '\\';
                str++;
            break;

            /* preserve backslashed quotes, dollar signs */
            case '\'':
            case '"':
            case '$':
                new_str[i++] = '\\';
                new_str[i++] = *str++;
            break;

            case 'b':
                new_str[i++] = '\b';
                str++;
            break;

            case 'f':
                new_str[i++] = '\f';
                str++;
            break;

            case 'r':
                new_str[i++] = '\r';
                str++;
            break;

            case 'n':
                new_str[i++] = '\n';
                str++;
            break;

            case 's':
                new_str[i++] = ' ';
                str++;
            break;

            case 't':
                new_str[i++] = '\t';
                str++;
            break;

            case 'v':
                new_str[i++] = '\13';
                str++;
            break;

            case 'z':
                str++;
            break;

            case '0': case '1': case '2': case '3': case '4':
            case '5': case '6': case '7': case '8': case '9': {
                char val;

                /* Three digit octal constant? */
                if (*str >= '0' && *str <= '3' &&
                    *(str + 1) >= '0' && *(str + 1) <= '7' &&
                    *(str + 2) >= '0' && *(str + 2) <= '7') {

                    val = (DIGIT(*str) << 6) +
                        (DIGIT(*(str + 1)) << 3) +
                        DIGIT(*(str + 2));

                    /*
                     * Allow null value if user really
                     * wants to shoot at feet, but beware!
                     */
                    new_str[i++] = val;
                    str += 3;
                    break;
                }

                /*
                 * One or two digit hex constant?
                 * If two are there they will both be taken.
                 * Use \z to split them up if this is not
                 * wanted.
                 */
                if (*str == '0' &&
                    (*(str + 1) == 'x' || *(str + 1) == 'X') &&
                    isxdigit(*(str + 2))) {
                    val = DIGIT(*(str + 2));
                    if (isxdigit(*(str + 3))) {
                        val = (val << 4) +
                            DIGIT(*(str + 3));
                        str += 4;
                    } else
                        str += 3;
                    /* Yep, allow null value here too */
                    new_str[i++] = val;
                    break;
                }
            }
            break;

            default:
                new_str[i++] = *str++;
            break;
            }
        } else {
            if (*str == '\\') {
                seenbs = 1;
                str++;
            } else
                new_str[i++] = *str++;
        }
    }

    if (seenbs) {
        /*
         * The final character was a '\'.
         * Put it in as a single backslash.
         */
        new_str[i++] = '\\';
    }
    new_str[i] = '\0';
    return (new_str);
}

/*
 * parse: accept a string of input and "parse" it for backslash
 * substitutions and environment variable expansions (${var}),
 * returning an argc/argv style vector of whitespace separated
 * arguments.  Returns 0 on success, 1 on failure (ok, ok, so I
 * wimped-out on the error codes! :).
 *
 * Note that the argv array returned must be freed by the caller, but
 * we own the space allocated for arguments and will free that on next
 * invocation.  This allows argv consumers to modify the array if
 * required.
 *
 * NB: environment variables that expand to more than one whitespace
 * separated token will be returned as a single argv[] element, not
 * split in turn.  Expanded text is also immune to further backslash
 * elimination or expansion since this is a one-pass, non-recursive
 * parser.  You didn't specify more than this so if you want more, ask
 * me. - jkh
 */

#define PARSE_FAIL(expr)    \
if (expr) { \
    printf("fail at line %d\n", __LINE__); \
    clean(); \
    free(copy); \
    free(buf); \
    return (1); \
}

/* Accept the usual delimiters for a variable, returning counterpart */
static char
isdelim(int ch)
{
    if (ch == '{')
        return ('}');
    else if (ch == '(')
        return (')');
    return ('\0');
}

static int
isquote(int ch)
{
    return (ch == '\'');
}

static int
isdquote(int ch)
{
    return (ch == '"');
}

int
parse(int *argc, char ***argv, char *str)
{
    int ac;
    char *val, *p, *q, *copy = NULL;
    size_t i = 0;
    char token, tmp, quote, dquote, *buf;
    enum { STR, VAR, WHITE } state;

    ac = *argc = 0;
    dquote = quote = 0;
    if (!str || (p = copy = backslash(str)) == NULL)
        return (1);

    /* Initialize vector and state */
    clean();
    state = STR;
    buf = (char *)malloc(PARSE_BUFSIZE);
    token = 0;

    /* And awaaaaaaaaay we go! */
    while (*p) {
        switch (state) {
        case STR:
            if ((*p == '\\') && p[1]) {
                p++;
                PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
                buf[i++] = *p++;
            } else if (isquote(*p)) {
                quote = quote ? 0 : *p;
                if (dquote) { /* keep quote */
                    PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
                    buf[i++] = *p++;
                } else
                    ++p;
            } else if (isdquote(*p)) {
                dquote = dquote ? 0 : *p;
                if (quote) { /* keep dquote */
                    PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
                    buf[i++] = *p++;
                } else
                    ++p;
            } else if (isspace(*p) && !quote && !dquote) {
                state = WHITE;
                if (i) {
                    buf[i] = '\0';
                    PARSE_FAIL(insert(&ac, buf));
                    i = 0;
                }
                ++p;
            } else if (*p == '$' && !quote) {
                token = isdelim(*(p + 1));
                if (token)
                    p += 2;
                else
                    ++p;
                state = VAR;
            } else {
                PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
                buf[i++] = *p++;
            }
        break;

        case WHITE:
            if (isspace(*p))
                ++p;
            else
                state = STR;
        break;

        case VAR:
            if (token) {
                PARSE_FAIL((q = strchr(p, token)) == NULL);
            } else {
                q = p;
                while (*q && !isspace(*q))
                ++q;
            }
            tmp = *q;
            *q = '\0';
            if ((val = getenv(p)) != NULL) {
                size_t len = strlen(val);

                strncpy(buf + i, val, PARSE_BUFSIZE - (i + 1));
                i += min(len, PARSE_BUFSIZE - 1);
            }
            *q = tmp;   /* restore value */
            p = q + (token ? 1 : 0);
            state = STR;
        break;
        }
    }
    /* missing terminating ' or " */
    PARSE_FAIL(quote || dquote);
    /* If at end of token, add it */
    if (i && state == STR) {
        buf[i] = '\0';
        PARSE_FAIL(insert(&ac, buf));
    }
    args[ac] = NULL;
    *argc = ac;
    *argv = (char **)malloc((sizeof (char *) * ac + 1));
    bcopy(args, *argv, sizeof (char *) * ac + 1);
    free(buf);
    free(copy);
    return (0);
}

#define MAXARGS 20

/* Clean vector space */
static void
clean(void)
{
    int i;

    for (i = 0; i < MAXARGS; i++) {
        if (args[i] != NULL) {
            free(args[i]);
            args[i] = NULL;
        }
    }
}

static int
insert(int *argcp, char *buf)
{
    if (*argcp >= MAXARGS)
        return (1);
    args[(*argcp)++] = strdup(buf);
    return (0);
}

static char *
isadir(void)
{
    char *buf;
    size_t bufsize = 20;
    int ret;

    if ((buf = malloc(bufsize)) == NULL)
        return (NULL);
    ret = sysinfo(SI_ARCHITECTURE_K, buf, bufsize);
    if (ret == -1) {
        free(buf);
        return (NULL);
    }
    return (buf);
}

/*
 * Shim for taking commands from BF and passing them out to 'standard'
 * argv/argc command functions.
 */
static void
bf_command(ficlVm *vm)
{
    char *name, *line, *tail, *cp;
    size_t len;
    struct bootblk_command *cmdp;
    bootblk_cmd_t *cmd;
    int nstrings, i;
    int argc, result;
    char **argv;

    /* Get the name of the current word */
    name = vm->runningWord->name;

    /* Find our command structure */
    cmd = NULL;
    STAILQ_FOREACH(cmdp, &commands, next) {
        if ((cmdp->c_name != NULL) && strcmp(name, cmdp->c_name) == 0)
            cmd = cmdp->c_fn;
    }
    if (cmd == NULL)
        printf("callout for unknown command '%s'\n", name);

    /* Check whether we have been compiled or are being interpreted */
    if (ficlStackPopInteger(ficlVmGetDataStack(vm))) {
        /*
         * Get parameters from stack, in the format:
         * an un ... a2 u2 a1 u1 n --
         * Where n is the number of strings, a/u are pairs of
         * address/size for strings, and they will be concatenated
         * in LIFO order.
         */
        nstrings = ficlStackPopInteger(ficlVmGetDataStack(vm));
        for (i = 0, len = 0; i < nstrings; i++)
        len += ficlStackFetch(ficlVmGetDataStack(vm), i * 2).i + 1;
        line = malloc(strlen(name) + len + 1);
        strcpy(line, name);

        if (nstrings)
            for (i = 0; i < nstrings; i++) {
                len = ficlStackPopInteger(
                    ficlVmGetDataStack(vm));
                cp = ficlStackPopPointer(
                    ficlVmGetDataStack(vm));
                strcat(line, " ");
                strncat(line, cp, len);
            }
    } else {
        /* Get remainder of invocation */
        tail = ficlVmGetInBuf(vm);
        for (cp = tail, len = 0;
            cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++)
            ;

        line = malloc(strlen(name) + len + 2);
        strcpy(line, name);
        if (len > 0) {
            strcat(line, " ");
            strncat(line, tail, len);
            ficlVmUpdateTib(vm, tail + len);
        }
    }

    command_errmsg = command_errbuf;
    command_errbuf[0] = 0;
    if (!parse(&argc, &argv, line)) {
        result = (cmd)(argc, argv);
        free(argv);
    } else {
        result = BF_PARSE;
    }
    free(line);
    /*
     * If there was error during nested ficlExec(), we may no longer have
     * valid environment to return.  Throw all exceptions from here.
     */
    if (result != 0)
        ficlVmThrow(vm, result);
    /* This is going to be thrown!!! */
    ficlStackPushInteger(ficlVmGetDataStack(vm), result);
}

static char *
get_currdev(void)
{
    int ret;
    char *currdev;
    FILE *fp;
    struct mnttab mpref = {0};
    struct mnttab mp = {0};

    mpref.mnt_mountp = "/";
    fp = fopen(MNTTAB, "r");

    /* do the best we can to return something... */
    if (fp == NULL)
        return (strdup(":"));

    ret = getmntany(fp, &mp, &mpref);
    (void) fclose(fp);
    if (ret == 0)
        (void) asprintf(&currdev, "zfs:%s:", mp.mnt_special);
    else
        return (strdup(":"));

    return (currdev);
}

/*
 * Replace a word definition (a builtin command) with another
 * one that:
 *
 *        - Throw error results instead of returning them on the stack
 *        - Pass a flag indicating whether the word was compiled or is
 *          being interpreted.
 *
 * There is one major problem with builtins that cannot be overcome
 * in anyway, except by outlawing it. We want builtins to behave
 * differently depending on whether they have been compiled or they
 * are being interpreted. Notice that this is *not* the interpreter's
 * current state. For example:
 *
 * : example ls ; immediate
 * : problem example ;      \ "ls" gets executed while compiling
 * example          \ "ls" gets executed while interpreting
 *
 * Notice that, though the current state is different in the two
 * invocations of "example", in both cases "ls" has been
 * *compiled in*, which is what we really want.
 *
 * The problem arises when you tick the builtin. For example:
 *
 * : example-1 ['] ls postpone literal ; immediate
 * : example-2 example-1 execute ; immediate
 * : problem example-2 ;
 * example-2
 *
 * We have no way, when we get EXECUTEd, of knowing what our behavior
 * should be. Thus, our only alternative is to "outlaw" this. See RFI
 * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related
 * problem, concerning compile semantics.
 *
 * The problem is compounded by the fact that "' builtin CATCH" is valid
 * and desirable. The only solution is to create an intermediary word.
 * For example:
 *
 * : my-ls ls ;
 * : example ['] my-ls catch ;
 *
 * So, with the below implementation, here is a summary of the behavior
 * of builtins:
 *
 * ls -l                \ "interpret" behavior, ie,
 *                  \ takes parameters from TIB
 * : ex-1 s" -l" 1 ls ;         \ "compile" behavior, ie,
 *                  \ takes parameters from the stack
 * : ex-2 ['] ls catch ; immediate  \ undefined behavior
 * : ex-3 ['] ls catch ;        \ undefined behavior
 * ex-2 ex-3                \ "interpret" behavior,
 *                  \ catch works
 * : ex-4 ex-2 ;            \ "compile" behavior,
 *                  \ catch does not work
 * : ex-5 ex-3 ; immediate      \ same as ex-2
 * : ex-6 ex-3 ;            \ same as ex-3
 * : ex-7 ['] ex-1 catch ;      \ "compile" behavior,
 *                  \ catch works
 * : ex-8 postpone ls ; immediate   \ same as ex-2
 * : ex-9 postpone ls ;         \ same as ex-3
 *
 * As the definition below is particularly tricky, and it's side effects
 * must be well understood by those playing with it, I'll be heavy on
 * the comments.
 *
 * (if you edit this definition, pay attention to trailing spaces after
 *  each word -- I warned you! :-) )
 */
#define BUILTIN_CONSTRUCTOR \
": builtin: "       \
">in @ "        /* save the tib index pointer */ \
"' "            /* get next word's xt */ \
"swap >in ! "       /* point again to next word */ \
"create "       /* create a new definition of the next word */ \
", "            /* save previous definition's xt */ \
"immediate "        /* make the new definition an immediate word */ \
            \
"does> "        /* Now, the *new* definition will: */ \
"state @ if "       /* if in compiling state: */ \
"1 postpone literal "   /* pass 1 flag to indicate compile */ \
"@ compile, "       /* compile in previous definition */ \
"postpone throw "       /* throw stack-returned result */ \
"else "     /* if in interpreting state: */ \
"0 swap "           /* pass 0 flag to indicate interpret */ \
"@ execute "        /* call previous definition */ \
"throw "            /* throw stack-returned result */ \
"then ; "

extern int ficlExecFD(ficlVm *, int);
#define COMMAND_SET(ptr, name, desc, fn)        \
    ptr = malloc(sizeof (struct bootblk_command));  \
    ptr->c_name = (name);               \
    ptr->c_desc = (desc);               \
    ptr->c_fn = (fn);

/*
 * Initialise the Forth interpreter, create all our commands as words.
 */
ficlVm *
bf_init(const char *rc, ficlOutputFunction out)
{
    struct bootblk_command *cmdp;
    char create_buf[41];    /* 31 characters-long builtins */
    char *buf;
    int fd, rv;
    ficlSystemInformation *fsi;
    ficlDictionary *dict;
    ficlDictionary *env;

    /* set up commands list */
    STAILQ_INIT(&commands);
    COMMAND_SET(cmdp, "help", "detailed help", command_help);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "?", "list commands", command_commandlist);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "show", "show variable(s)", command_show);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "printenv", "show variable(s)", command_show);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "set", "set a variable", command_set);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "setprop", "set a variable", command_setprop);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "unset", "unset a variable", command_unset);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "echo", "echo arguments", command_echo);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "read", "read input from the terminal", command_read);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "more", "show contents of a file", command_more);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "ls", "list files", command_ls);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "include", "read commands from a file",
        command_include);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "boot", "boot a file or loaded kernel", command_boot);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "autoboot", "boot automatically after a delay",
        command_autoboot);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "load", "load a kernel or module", command_load);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "unload", "unload all modules", command_unload);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);
    COMMAND_SET(cmdp, "reboot", "reboot the system", command_reboot);
    STAILQ_INSERT_TAIL(&commands, cmdp, next);

    fsi = malloc(sizeof (ficlSystemInformation));
    ficlSystemInformationInitialize(fsi);
    fsi->textOut = out;
    fsi->dictionarySize = BF_DICTSIZE;

    bf_sys = ficlSystemCreate(fsi);
    free(fsi);
    ficlSystemCompileExtras(bf_sys);
    bf_vm = ficlSystemCreateVm(bf_sys);

    buf = isadir();
    if (buf == NULL || strcmp(buf, "amd64") != 0) {
        (void) setenv("ISADIR", "", 1);
    } else {
        (void) setenv("ISADIR", buf, 1);
    }
    if (buf != NULL)
        free(buf);
    buf = get_currdev();
    (void) setenv("currdev", buf, 1);
    free(buf);

    /* Put all private definitions in a "builtins" vocabulary */
    rv = ficlVmEvaluate(bf_vm,
        "vocabulary builtins also builtins definitions");
    if (rv != FICL_VM_STATUS_OUT_OF_TEXT) {
        printf("error interpreting forth: %d\n", rv);
        exit(1);
    }

    /* Builtin constructor word  */
    rv = ficlVmEvaluate(bf_vm, BUILTIN_CONSTRUCTOR);
    if (rv != FICL_VM_STATUS_OUT_OF_TEXT) {
        printf("error interpreting forth: %d\n", rv);
        exit(1);
    }

    /* make all commands appear as Forth words */
    dict = ficlSystemGetDictionary(bf_sys);
    cmdp = NULL;
    STAILQ_FOREACH(cmdp, &commands, next) {
        ficlDictionaryAppendPrimitive(dict, (char *)cmdp->c_name,
            bf_command, FICL_WORD_DEFAULT);
        rv = ficlVmEvaluate(bf_vm, "forth definitions builtins");
        if (rv != FICL_VM_STATUS_OUT_OF_TEXT) {
            printf("error interpreting forth: %d\n", rv);
            exit(1);
        }
        sprintf(create_buf, "builtin: %s", cmdp->c_name);
        rv = ficlVmEvaluate(bf_vm, create_buf);
        if (rv != FICL_VM_STATUS_OUT_OF_TEXT) {
            printf("error interpreting forth: %d\n", rv);
            exit(1);
        }
        rv = ficlVmEvaluate(bf_vm, "builtins definitions");
        if (rv != FICL_VM_STATUS_OUT_OF_TEXT) {
            printf("error interpreting forth: %d\n", rv);
            exit(1);
        }
    }
    rv = ficlVmEvaluate(bf_vm, "only forth definitions");
    if (rv != FICL_VM_STATUS_OUT_OF_TEXT) {
        printf("error interpreting forth: %d\n", rv);
        exit(1);
    }

    /*
     * Export some version numbers so that code can detect the
     * loader/host version
     */
    env = ficlSystemGetEnvironment(bf_sys);
    ficlDictionarySetConstant(env, "loader_version",
        (bootprog_rev[0] - '0') * 10 + (bootprog_rev[2] - '0'));

    /* try to load and run init file if present */
    if (rc == NULL)
        rc = "/boot/forth/boot.4th";
    if (*rc != '\0') {
        fd = open(rc, O_RDONLY);
        if (fd != -1) {
            (void) ficlExecFD(bf_vm, fd);
            close(fd);
        }
    }

    return (bf_vm);
}

void
bf_fini(void)
{
    ficlSystemDestroy(bf_sys);
}

/*
 * Feed a line of user input to the Forth interpreter
 */
int
bf_run(char *line)
{
    int result;
    ficlString s;

    FICL_STRING_SET_FROM_CSTRING(s, line);
    result = ficlVmExecuteString(bf_vm, s);

    switch (result) {
    case FICL_VM_STATUS_OUT_OF_TEXT:
    case FICL_VM_STATUS_ABORTQ:
    case FICL_VM_STATUS_QUIT:
    case FICL_VM_STATUS_ERROR_EXIT:
    break;
    case FICL_VM_STATUS_USER_EXIT:
    break;
    case FICL_VM_STATUS_ABORT:
        printf("Aborted!\n");
    break;
    case BF_PARSE:
        printf("Parse error!\n");
    break;
    default:
        if (command_errmsg != NULL) {
            printf("%s\n", command_errmsg);
            command_errmsg = NULL;
        }
    }

    setenv("interpret", bf_vm->state ? "" : "ok", 1);

    return (result);
}

char *
get_dev(const char *path)
{
    FILE *fp;
    struct mnttab mpref = {0};
    struct mnttab mp = {0};
    char *currdev;
    int ret;
    char *buf;
    char *tmppath;
    char *tmpdev;
    char *cwd = NULL;

    fp = fopen(MNTTAB, "r");

    /* do the best we can to return something... */
    if (fp == NULL)
        return (strdup(path));

    /*
     * the path can have device provided, check for it
     * and extract it.
     */
    buf = strrchr(path, ':');
    if (buf != NULL) {
        tmppath = buf+1;        /* real path */
        buf = strchr(path, ':');    /* skip zfs: */
        buf++;
        tmpdev = strdup(buf);
        buf = strchr(tmpdev, ':');  /* get ending : */
        *buf = '\0';
    } else {
        tmppath = (char *)path;
        if (tmppath[0] != '/')
            if ((cwd = getcwd(NULL, PATH_MAX)) == NULL) {
                (void) fclose(fp);
                return (strdup(path));
            }

        currdev = getenv("currdev");
        buf = strchr(currdev, ':'); /* skip zfs: */
        if (buf == NULL) {
            (void) fclose(fp);
            return (strdup(path));
        }
        buf++;
        tmpdev = strdup(buf);
        buf = strchr(tmpdev, ':');  /* get ending : */
        *buf = '\0';
    }

    mpref.mnt_special = tmpdev;
    ret = getmntany(fp, &mp, &mpref);
    (void) fclose(fp);
    free(tmpdev);

    if (cwd == NULL)
        (void) asprintf(&buf, "%s/%s", ret? "":mp.mnt_mountp, tmppath);
    else {
        (void) asprintf(&buf, "%s/%s/%s", ret? "":mp.mnt_mountp, cwd,
            tmppath);
        free(cwd);
    }
    return (buf);
}

static void
ngets(char *buf, int n)
{
    int c;
    char *lp;

    for (lp = buf; ; )
        switch (c = getchar() & 0177) {
        case '\n':
        case '\r':
            *lp = '\0';
            putchar('\n');
        return;
        case '\b':
        case '\177':
            if (lp > buf) {
                lp--;
                putchar('\b');
                putchar(' ');
                putchar('\b');
            }
        break;
        case 'r'&037: {
            char *p;

            putchar('\n');
            for (p = buf; p < lp; ++p)
                putchar(*p);
        break;
        }
        case 'u'&037:
        case 'w'&037:
            lp = buf;
            putchar('\n');
        break;
        default:
            if ((n < 1) || ((lp - buf) < n - 1)) {
                *lp++ = c;
                putchar(c);
            }
        }
    /*NOTREACHED*/
}

static int
fgetstr(char *buf, int size, int fd)
{
    char c;
    int err, len;

    size--;         /* leave space for terminator */
    len = 0;
    while (size != 0) {
        err = read(fd, &c, sizeof (c));
        if (err < 0)            /* read error */
            return (-1);

        if (err == 0) { /* EOF */
            if (len == 0)
                return (-1);    /* nothing to read */
            break;
        }
        if ((c == '\r') || (c == '\n')) /* line terminators */
            break;
        *buf++ = c;         /* keep char */
        size--;
        len++;
    }
    *buf = 0;
    return (len);
}

static char *
unargv(int argc, char *argv[])
{
    size_t hlong;
    int i;
    char *cp;

    for (i = 0, hlong = 0; i < argc; i++)
        hlong += strlen(argv[i]) + 2;

    if (hlong == 0)
        return (NULL);

    cp = malloc(hlong);
    cp[0] = 0;
    for (i = 0; i < argc; i++) {
        strcat(cp, argv[i]);
        if (i < (argc - 1))
            strcat(cp, " ");
    }

    return (cp);
}

/*
 * Help is read from a formatted text file.
 *
 * Entries in the file are formatted as:
 * # Ttopic [Ssubtopic] Ddescription
 * help
 * text
 * here
 * #
 *
 * Note that for code simplicity's sake, the above format must be followed
 * exactly.
 *
 * Subtopic entries must immediately follow the topic (this is used to
 * produce the listing of subtopics).
 *
 * If no argument(s) are supplied by the user, the help for 'help' is displayed.
 */
static int
help_getnext(int fd, char **topic, char **subtopic, char **desc)
{
    char line[81], *cp, *ep;

    for (;;) {
        if (fgetstr(line, 80, fd) < 0)
            return (0);

        if ((strlen(line) < 3) || (line[0] != '#') || (line[1] != ' '))
            continue;

        *topic = *subtopic = *desc = NULL;
        cp = line + 2;
        while ((cp != NULL) && (*cp != 0)) {
            ep = strchr(cp, ' ');
            if ((*cp == 'T') && (*topic == NULL)) {
                if (ep != NULL)
                    *ep++ = 0;
                *topic = strdup(cp + 1);
            } else if ((*cp == 'S') && (*subtopic == NULL)) {
                if (ep != NULL)
                    *ep++ = 0;
                *subtopic = strdup(cp + 1);
            } else if (*cp == 'D') {
                *desc = strdup(cp + 1);
                ep = NULL;
            }
            cp = ep;
        }
        if (*topic == NULL) {
            if (*subtopic != NULL)
                free(*subtopic);
            if (*desc != NULL)
                free(*desc);
            continue;
        }
        return (1);
    }
}

static int
help_emitsummary(char *topic, char *subtopic, char *desc)
{
    int i;

    pager_output("    ");
    pager_output(topic);
    i = strlen(topic);
    if (subtopic != NULL) {
        pager_output(" ");
        pager_output(subtopic);
        i += strlen(subtopic) + 1;
    }
    if (desc != NULL) {
        do {
            pager_output(" ");
        } while (i++ < 30);
        pager_output(desc);
    }
    return (pager_output("\n"));
}

static int
command_help(int argc, char *argv[])
{
    char buf[81];   /* XXX buffer size? */
    int hfd, matched, doindex;
    char *topic, *subtopic, *t, *s, *d;

    /* page the help text from our load path */
    sprintf(buf, "/boot/loader.help");
    if ((hfd = open(buf, O_RDONLY)) < 0) {
        printf("Verbose help not available, "
            "use '?' to list commands\n");
        return (CMD_OK);
    }

    /* pick up request from arguments */
    topic = subtopic = NULL;
    switch (argc) {
    case 3:
        subtopic = strdup(argv[2]);
    case 2:
        topic = strdup(argv[1]);
    break;
    case 1:
        topic = strdup("help");
    break;
    default:
        command_errmsg = "usage is 'help <topic> [<subtopic>]";
        close(hfd);
        return (CMD_ERROR);
    }

    /* magic "index" keyword */
    doindex = strcmp(topic, "index") == 0;
    matched = doindex;

    /* Scan the helpfile looking for help matching the request */
    pager_open();
    while (help_getnext(hfd, &t, &s, &d)) {
        if (doindex) {      /* dink around formatting */
            if (help_emitsummary(t, s, d))
                break;

        } else if (strcmp(topic, t)) {
            /* topic mismatch */
            /* nothing more on this topic, stop scanning */
            if (matched)
                break;
        } else {
            /* topic matched */
            matched = 1;
            if (((subtopic == NULL) && (s == NULL)) ||
                ((subtopic != NULL) && (s != NULL) &&
                strcmp(subtopic, s) == 0)) {
                /* exact match, print text */
                while ((fgetstr(buf, 80, hfd) >= 0) &&
                    (buf[0] != '#')) {
                    if (pager_output(buf))
                        break;
                    if (pager_output("\n"))
                        break;
                }
            } else if ((subtopic == NULL) && (s != NULL)) {
                /* topic match, list subtopics */
                if (help_emitsummary(t, s, d))
                    break;
            }
        }
        free(t);
        free(s);
        free(d);
    }
    pager_close();
    close(hfd);
    if (!matched) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "no help available for '%s'", topic);
        free(topic);
        if (subtopic)
            free(subtopic);
        return (CMD_ERROR);
    }
    free(topic);
    if (subtopic)
        free(subtopic);
    return (CMD_OK);
}

static int
command_commandlist(int argc, char *argv[])
{
    struct bootblk_command *cmdp;
    int res;
    char name[20];

    res = 0;
    pager_open();
    res = pager_output("Available commands:\n");
    cmdp = NULL;
    STAILQ_FOREACH(cmdp, &commands, next) {
        if (res)
            break;
        if ((cmdp->c_name != NULL) && (cmdp->c_desc != NULL)) {
            sprintf(name, "  %-15s  ", cmdp->c_name);
            pager_output(name);
            pager_output(cmdp->c_desc);
            res = pager_output("\n");
        }
    }
    pager_close();
    return (CMD_OK);
}

/*
 * XXX set/show should become set/echo if we have variable
 * substitution happening.
 */
static int
command_show(int argc, char *argv[])
{
    char **ev;
    char *cp;

    if (argc < 2) {
        /*
         * With no arguments, print everything.
         */
        pager_open();
        for (ev = _environ; *ev != NULL; ev++) {
            pager_output(*ev);
            cp = getenv(*ev);
            if (cp != NULL) {
                pager_output("=");
                pager_output(cp);
            }
            if (pager_output("\n"))
                break;
        }
        pager_close();
    } else {
        if ((cp = getenv(argv[1])) != NULL) {
            printf("%s\n", cp);
        } else {
            snprintf(command_errbuf, sizeof (command_errbuf),
                "variable '%s' not found", argv[1]);
            return (CMD_ERROR);
        }
    }
    return (CMD_OK);
}

static int
command_set(int argc, char *argv[])
{
    int err;
    char    *value, *copy;

    if (argc != 2) {
        command_errmsg = "wrong number of arguments";
        return (CMD_ERROR);
    } else {
        copy = strdup(argv[1]);
        if (copy == NULL) {
            command_errmsg = strerror(errno);
            return (CMD_ERROR);
        }
        if ((value = strchr(copy, '=')) != NULL)
            *(value++) = 0;
        else
            value = "";
        if ((err = setenv(copy, value, 1)) != 0) {
            free(copy);
            command_errmsg = strerror(errno);
            return (CMD_ERROR);
        }
        free(copy);
    }
    return (CMD_OK);
}

static int
command_setprop(int argc, char *argv[])
{
    int err;

    if (argc != 3) {
        command_errmsg = "wrong number of arguments";
        return (CMD_ERROR);
    } else {
        if ((err = setenv(argv[1], argv[2], 1)) != 0) {
            command_errmsg = strerror(err);
            return (CMD_ERROR);
        }
    }
    return (CMD_OK);
}

static int
command_unset(int argc, char *argv[])
{
    int err;

    if (argc != 2) {
        command_errmsg = "wrong number of arguments";
        return (CMD_ERROR);
    } else {
        if ((err = unsetenv(argv[1])) != 0) {
            command_errmsg = strerror(err);
            return (CMD_ERROR);
        }
    }
    return (CMD_OK);
}

static int
command_echo(int argc, char *argv[])
{
    char *s;
    int nl, ch;

    nl = 0;
    optind = 1;
    opterr = 1;
    while ((ch = getopt(argc, argv, "n")) != -1) {
        switch (ch) {
        case 'n':
            nl = 1;
        break;
        case '?':
        default:
            /* getopt has already reported an error */
        return (CMD_OK);
        }
    }
    argv += (optind);
    argc -= (optind);

    s = unargv(argc, argv);
    if (s != NULL) {
        printf("%s", s);
        free(s);
    }
    if (!nl)
        printf("\n");
    return (CMD_OK);
}

/*
 * A passable emulation of the sh(1) command of the same name.
 */
static int
ischar(void)
{
    return (1);
}

static int
command_read(int argc, char *argv[])
{
    char *prompt;
    int timeout;
    time_t when;
    char *cp;
    char *name;
    char buf[256];      /* XXX size? */
    int c;

    timeout = -1;
    prompt = NULL;
    optind = 1;
    opterr = 1;
    while ((c = getopt(argc, argv, "p:t:")) != -1) {
        switch (c) {
        case 'p':
            prompt = optarg;
        break;
        case 't':
            timeout = strtol(optarg, &cp, 0);
            if (cp == optarg) {
                snprintf(command_errbuf,
                    sizeof (command_errbuf),
                    "bad timeout '%s'", optarg);
                return (CMD_ERROR);
            }
        break;
        default:
        return (CMD_OK);
        }
    }

    argv += (optind);
    argc -= (optind);
    name = (argc > 0) ? argv[0]: NULL;

    if (prompt != NULL)
        printf("%s", prompt);
    if (timeout >= 0) {
        when = time(NULL) + timeout;
        while (!ischar())
            if (time(NULL) >= when)
                return (CMD_OK); /* is timeout an error? */
    }

    ngets(buf, sizeof (buf));

    if (name != NULL)
        setenv(name, buf, 1);
    return (CMD_OK);
}

/*
 * File pager
 */
static int
command_more(int argc, char *argv[])
{
    int i;
    int res;
    char line[80];
    char *name;

    res = 0;
    pager_open();
    for (i = 1; (i < argc) && (res == 0); i++) {
        sprintf(line, "*** FILE %s BEGIN ***\n", argv[i]);
        if (pager_output(line))
            break;
        name = get_dev(argv[i]);
        res = page_file(name);
        free(name);
        if (!res) {
            sprintf(line, "*** FILE %s END ***\n", argv[i]);
            res = pager_output(line);
        }
    }
    pager_close();

    if (res == 0)
        return (CMD_OK);
    return (CMD_ERROR);
}

static int
page_file(char *filename)
{
    int result;

    result = pager_file(filename);

    if (result == -1) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "error showing %s", filename);
    }

    return (result);
}

static int
command_ls(int argc, char *argv[])
{
    DIR *dir;
    int fd;
    struct stat sb;
    struct dirent *d;
    char *buf, *path;
    char lbuf[128]; /* one line */
    int result, ch;
    int verbose;

    result = CMD_OK;
    fd = -1;
    verbose = 0;
    optind = 1;
    opterr = 1;
    while ((ch = getopt(argc, argv, "l")) != -1) {
        switch (ch) {
        case 'l':
            verbose = 1;
        break;
        case '?':
        default:
            /* getopt has already reported an error */
        return (CMD_OK);
        }
    }
    argv += (optind - 1);
    argc -= (optind - 1);

    if (argc < 2) {
        path = "";
    } else {
        path = argv[1];
    }

    fd = ls_getdir(&path);
    if (fd == -1) {
        result = CMD_ERROR;
        goto out;
    }
    dir = fdopendir(fd);
    pager_open();
    pager_output(path);
    pager_output("\n");

    while ((d = readdir(dir)) != NULL) {
        if (strcmp(d->d_name, ".") && strcmp(d->d_name, "..")) {
            /* stat the file, if possible */
            sb.st_size = 0;
            sb.st_mode = 0;
            buf = malloc(strlen(path) + strlen(d->d_name) + 2);
            if (path[0] == '\0')
                sprintf(buf, "%s", d->d_name);
            else
                sprintf(buf, "%s/%s", path, d->d_name);
            /* ignore return, could be symlink, etc. */
            if (stat(buf, &sb))
                sb.st_size = 0;
            free(buf);
            if (verbose) {
                sprintf(lbuf, " %c %8d %s\n",
                    typestr[sb.st_mode >> 12],
                    (int)sb.st_size, d->d_name);
            } else {
                sprintf(lbuf, " %c  %s\n",
                    typestr[sb.st_mode >> 12], d->d_name);
            }
            if (pager_output(lbuf))
                goto out;
        }
    }
out:
    pager_close();
    if (fd != -1)
        closedir(dir);
    if (path != NULL)
        free(path);
    return (result);
}

/*
 * Given (path) containing a vaguely reasonable path specification, return an fd
 * on the directory, and an allocated copy of the path to the directory.
 */
static int
ls_getdir(char **pathp)
{
    struct stat sb;
    int fd;
    char *cp, *path;

    fd = -1;

    /* one extra byte for a possible trailing slash required */
    path = malloc(strlen(*pathp) + 2);
    strcpy(path, *pathp);

    /* Make sure the path is respectable to begin with */
    if ((cp = get_dev(path)) == NULL) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "bad path '%s'", path);
        goto out;
    }

    /* If there's no path on the device, assume '/' */
    if (*cp == 0)
        strcat(path, "/");

    fd = open(cp, O_RDONLY);
    if (fd < 0) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "open '%s' failed: %s", path, strerror(errno));
        goto out;
    }
    if (fstat(fd, &sb) < 0) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "stat failed: %s", strerror(errno));
        goto out;
    }
    if (!S_ISDIR(sb.st_mode)) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "%s: %s", path, strerror(ENOTDIR));
        goto out;
    }

    free(cp);
    *pathp = path;
    return (fd);

out:
    free(cp);
    free(path);
    *pathp = NULL;
    if (fd != -1)
        close(fd);
    return (-1);
}

static int
command_include(int argc, char *argv[])
{
    int i;
    int res;
    char **argvbuf;

    /*
     * Since argv is static, we need to save it here.
     */
    argvbuf = (char **)calloc(argc, sizeof (char *));
    for (i = 0; i < argc; i++)
        argvbuf[i] = strdup(argv[i]);

    res = CMD_OK;
    for (i = 1; (i < argc) && (res == CMD_OK); i++)
        res = include(argvbuf[i]);

    for (i = 0; i < argc; i++)
        free(argvbuf[i]);
    free(argvbuf);

    return (res);
}

/*
 * Header prepended to each line. The text immediately follows the header.
 * We try to make this short in order to save memory -- the loader has
 * limited memory available, and some of the forth files are very long.
 */
struct includeline
{
    struct includeline *next;
    int line;
    char text[];
};

int
include(const char *filename)
{
    struct includeline *script, *se, *sp;
    int res = CMD_OK;
    int prevsrcid, fd, line;
    char *cp, input[256]; /* big enough? */
    char *path;

    path = get_dev(filename);
    if (((fd = open(path, O_RDONLY)) == -1)) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "can't open '%s': %s", filename,
            strerror(errno));
        free(path);
        return (CMD_ERROR);
    }

    free(path);
    /*
     * Read the script into memory.
     */
    script = se = NULL;
    line = 0;

    while (fgetstr(input, sizeof (input), fd) >= 0) {
        line++;
        cp = input;
        /* Allocate script line structure and copy line, flags */
        if (*cp == '\0')
            continue;   /* ignore empty line, save memory */
        if (cp[0] == '\\' && cp[1] == ' ')
            continue;   /* ignore comment */

        sp = malloc(sizeof (struct includeline) + strlen(cp) + 1);
        /*
         * On malloc failure (it happens!), free as much as possible
         * and exit
         */
        if (sp == NULL) {
            while (script != NULL) {
                se = script;
                script = script->next;
                free(se);
            }
            snprintf(command_errbuf, sizeof (command_errbuf),
                "file '%s' line %d: memory allocation "
                "failure - aborting", filename, line);
            return (CMD_ERROR);
        }
        strcpy(sp->text, cp);
        sp->line = line;
        sp->next = NULL;

        if (script == NULL) {
            script = sp;
        } else {
            se->next = sp;
        }
        se = sp;
    }
    close(fd);

    /*
     * Execute the script
     */

    prevsrcid = bf_vm->sourceId.i;
    bf_vm->sourceId.i = fd+1;   /* 0 is user input device */

    res = CMD_OK;

    for (sp = script; sp != NULL; sp = sp->next) {
        res = bf_run(sp->text);
        if (res != FICL_VM_STATUS_OUT_OF_TEXT) {
            snprintf(command_errbuf, sizeof (command_errbuf),
                "Error while including %s, in the line %d:\n%s",
                filename, sp->line, sp->text);
            res = CMD_ERROR;
            break;
        } else
            res = CMD_OK;
    }

    bf_vm->sourceId.i = -1;
    (void) bf_run("");
    bf_vm->sourceId.i = prevsrcid;

    while (script != NULL) {
        se = script;
        script = script->next;
        free(se);
    }

    return (res);
}

static int
command_boot(int argc, char *argv[])
{
    return (CMD_OK);
}

static int
command_autoboot(int argc, char *argv[])
{
    return (CMD_OK);
}

static void
moduledir_rebuild(void)
{
    struct moduledir *mdp, *mtmp;
    const char *path, *cp, *ep;
    int cplen;

    path = getenv("module_path");
    if (path == NULL)
        path = default_searchpath;
    /*
     * Rebuild list of module directories if it changed
     */
    STAILQ_FOREACH(mdp, &moduledir_list, d_link)
        mdp->d_flags |= MDIR_REMOVED;

    for (ep = path; *ep != 0;  ep++) {
        cp = ep;
        for (; *ep != 0 && *ep != ';'; ep++)
            ;
        /*
         * Ignore trailing slashes
         */
        for (cplen = ep - cp; cplen > 1 && cp[cplen - 1] == '/';
            cplen--)
            ;
        STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
            if (strlen(mdp->d_path) != cplen ||
                bcmp(cp, mdp->d_path, cplen) != 0)
                continue;
            mdp->d_flags &= ~MDIR_REMOVED;
            break;
        }
        if (mdp == NULL) {
            mdp = malloc(sizeof (*mdp) + cplen + 1);
            if (mdp == NULL)
                return;
            mdp->d_path = (char *)(mdp + 1);
            bcopy(cp, mdp->d_path, cplen);
            mdp->d_path[cplen] = 0;
            mdp->d_hints = NULL;
            mdp->d_flags = 0;
            STAILQ_INSERT_TAIL(&moduledir_list, mdp, d_link);
        }
        if (*ep == 0)
            break;
    }
    /*
     * Delete unused directories if any
     */
    mdp = STAILQ_FIRST(&moduledir_list);
    while (mdp) {
        if ((mdp->d_flags & MDIR_REMOVED) == 0) {
            mdp = STAILQ_NEXT(mdp, d_link);
        } else {
            if (mdp->d_hints)
                free(mdp->d_hints);
            mtmp = mdp;
            mdp = STAILQ_NEXT(mdp, d_link);
            STAILQ_REMOVE(&moduledir_list, mtmp, moduledir, d_link);
            free(mtmp);
        }
    }
}

static char *
file_lookup(const char *path, const char *name, int namelen)
{
    struct stat st;
    char *result, *cp, *gz;
    int pathlen;

    pathlen = strlen(path);
    result = malloc(pathlen + namelen + 2);
    if (result == NULL)
        return (NULL);
    bcopy(path, result, pathlen);
    if (pathlen > 0 && result[pathlen - 1] != '/')
        result[pathlen++] = '/';
    cp = result + pathlen;
    bcopy(name, cp, namelen);
    cp += namelen;
    *cp = '\0';
    if (stat(result, &st) == 0 && S_ISREG(st.st_mode))
        return (result);
    /* also check for gz file */
    (void) asprintf(&gz, "%s.gz", result);
    if (gz != NULL) {
        int res = stat(gz, &st);
        free(gz);
        if (res == 0)
            return (result);
    }
    free(result);
    return (NULL);
}

static char *
file_search(const char *name)
{
    struct moduledir *mdp;
    struct stat sb;
    char *result;
    int namelen;

    if (name == NULL)
        return (NULL);
    if (*name == 0)
        return (strdup(name));

    if (strchr(name, '/') != NULL) {
        char *gz;
        if (stat(name, &sb) == 0)
            return (strdup(name));
        /* also check for gz file */
        (void) asprintf(&gz, "%s.gz", name);
        if (gz != NULL) {
            int res = stat(gz, &sb);
            free(gz);
            if (res == 0)
                return (strdup(name));
        }
        return (NULL);
    }

    moduledir_rebuild();
    result = NULL;
    namelen = strlen(name);
    STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
        result = file_lookup(mdp->d_path, name, namelen);
        if (result)
            break;
    }
    return (result);
}

static int
command_load(int argc, char *argv[])
{
    int dofile, ch;
    char *typestr = NULL;
    char *filename;
    dofile = 0;
    optind = 1;

    if (argc == 1) {
        command_errmsg = "no filename specified";
        return (CMD_ERROR);
    }

    while ((ch = getopt(argc, argv, "kt:")) != -1) {
        switch (ch) {
        case 'k':
            break;
        case 't':
            typestr = optarg;
            dofile = 1;
            break;
        case '?':
        default:
            return (CMD_OK);
        }
    }
    argv += (optind - 1);
    argc -= (optind - 1);
    if (dofile) {
        if ((typestr == NULL) || (*typestr == 0)) {
            command_errmsg = "invalid load type";
            return (CMD_ERROR);
        }
#if 0
        return (file_loadraw(argv[1], typestr, argc - 2, argv + 2, 1)
            ? CMD_OK : CMD_ERROR);
#endif
        return (CMD_OK);
    }

    filename = file_search(argv[1]);
    if (filename == NULL) {
        snprintf(command_errbuf, sizeof (command_errbuf),
            "can't find '%s'", argv[1]);
        return (CMD_ERROR);
    }
    setenv("kernelname", filename, 1);

    return (CMD_OK);
}

static int
command_unload(int argc, char *argv[])
{
    unsetenv("kernelname");
    return (CMD_OK);
}

static int
command_reboot(int argc, char *argv[])
{
    exit(0);
    return (CMD_OK);
}