+/* vi: set sw=4 ts=4: */
+/*
+ * devio: correctly read a region of a device
+ *
+ * A dd like program designed to read correctly from mtd character
+ * (and maybe block) devices. Allows access to specific regions
+ * of the device and allows output of numbers from specific locations.
+ *
+ * Copyright (C) 2005 John Bowler <jbowler@acm.org>
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished
+ * to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#ifndef S_ISSOCK
+#define S_ISSOCK(fd) 0
+#endif
+
+/* Define to 0 to remove the detailed help. */
+#ifndef HELP
+#define HELP 1
+#endif
+
+#ifndef STR_MAX
+#define STR_MAX 4096
+#endif
+
+/* common error-and-die functions - reduces code size slightly. */
+static int error_level = 1; /* Increased by write operations. */
+
+/* NDEBUG will only save about 600 bytes! */
+/* The noreturn attribute helps reduce size by 300 bytes, and removes
+ * warning messages
+ */
+#if NDEBUG
+static void do_die(const unsigned char *why) __attribute__((noreturn));
+static void do_die(const unsigned char *why) {
+ fprintf(stderr, "devio: %s\n", why);
+ exit(error_level);
+}
+#define die(a,b) do_die(a)
+#else
+static void do_die(const unsigned char *why, const unsigned char *infile)
+ __attribute__((noreturn));
+static void do_die(const unsigned char *why, const unsigned char *infile) {
+ fprintf(stderr, "devio: %s: %s\n", infile, why);
+ exit(error_level);
+}
+#define die(a,b) do_die((a),(b))
+#endif
+
+#if NDEBUG
+static void do_pdie(const unsigned char *why) __attribute__((noreturn));
+static void do_pdie(const unsigned char *why) {
+ fprintf(stderr, "devio: %s: %s\n", why, strerror(errno));
+ exit(error_level);
+}
+#define pdie(a,b) do_pdie(a)
+#else
+static void do_pdie(const unsigned char *why, const unsigned char *infile)
+ __attribute__((noreturn));
+static void do_pdie(const unsigned char *why, const unsigned char *infile) {
+ fprintf(stderr, "devio: %s: %s: %s\n", infile, why, strerror(errno));
+ exit(error_level);
+}
+#define pdie(a,b) do_pdie((a),(b))
+#endif
+
+/* This is a non-standard assert but it saves quite a lot of
+ * space (1kbyte) over the OS version.
+ */
+#if NDEBUG
+#define assert(condition) do;while(0)
+#elif 0 /* Expensive string asserts (lots of space in strings). */
+static void do_assert(const unsigned char *why)
+ __attribute__((noreturn));
+static void do_assert(const unsigned char *why) {
+ fprintf(stderr, "devio: internal error: %s\n", why);
+ exit(error_level);
+}
+#define assert(condition) do if (!(condition)) do_assert(#condition); while (0)
+#else
+static void do_assert(int line) __attribute__((noreturn));
+static void do_assert(int line) {
+ fprintf(stderr, "devio: internal error: %d\n", line);
+ exit(error_level);
+}
+#define assert(condition) do if (!(condition)) do_assert(__LINE__); while (0)
+#endif
+
+/* This is a non-ANSI extension. */
+unsigned char *my_strdup(const unsigned char *from) {
+ size_t cb = strlen(from)+1;
+ unsigned char *to = malloc(cb);
+ if (to == 0)
+ die("out of memory", from);
+ memcpy(to, from, cb);
+ return to;
+}
+
+
+/***********************************************************************
+ * mtd_file
+ *
+ * Basic device safe IO.
+ * Set mtd_seek to set the desired read or write point.
+ * Use mtd_getb and mtd_putb to read/write a single byte.
+ * Use mtd_readbytes and mtd_writebytes to move multiple bytes.
+ *********************************************************************/
+/* File structure, used for read and write operations. stdio() should do
+ * everything this does pretty much except that this allows for no-write
+ * buffering and it is 'weird' in that it won't overwrite beyond the end
+ * of the data. */
+typedef struct mtd_file {
+ unsigned char* pname;
+ int fwrite;
+ int fverify; /* do not write, just verify */
+ int fwritten; /* something to do! */
+ int fchanged; /* something was done! */
+ int fd;
+ struct stat stat;
+ size_t cbbuf;
+ /* The user pointer is at 'useroffset', the buffer contains data from
+ * 'bufferoffset' to 'deviceoffset' (exclusive - the buffer may be empty), so
+ * the file descriptor is pointing to 'deviceoffset', which may be just beyond
+ * the end of the file.
+ */
+ off_t useroffset; /* Current user position */
+ off_t bufferoffset; /* Base of current buffer */
+ off_t deviceoffset; /* End of current buffer */
+ off_t endoffset; /* Length of char or block device. */
+ unsigned char* pbuf;
+ unsigned char* pwritebuf;
+} mtd_file;
+
+
+/* Initialise an mtd structure. */
+static void init_mtd(mtd_file *pfile) {
+ pfile->pname = 0;
+ pfile->fwrite = 0;
+ pfile->fverify = 0;
+ pfile->fwritten = 0;
+ pfile->fchanged = 0;
+ pfile->fd = (-1);
+ memset(&pfile->stat, 0, sizeof pfile->stat);
+ pfile->cbbuf = 0;
+ pfile->useroffset = 0;
+ pfile->bufferoffset = 0;
+ pfile->deviceoffset = 0;
+ pfile->endoffset = (off_t)-1;
+ pfile->pbuf = 0;
+ pfile->pwritebuf = 0;
+}
+
+
+/* Return the size, in bytes. */
+static size_t size_mtd(mtd_file *pfile) {
+ if (S_ISCHR(pfile->stat.st_mode) || S_ISBLK(pfile->stat.st_mode)) {
+ if (pfile->endoffset == (off_t)-1) {
+ off_t len;
+ assert(pfile->stat.st_size == 0);
+ assert(pfile->stat.st_blocks == 0);
+ assert(pfile->stat.st_blksize > 0);
+ /* So seek to the end then come back here. */
+ len = lseek(pfile->fd, -pfile->stat.st_blksize, SEEK_END);
+ if (len == (off_t)-1)
+ pdie("lseek(length)", pfile->pname);
+ if (lseek(pfile->fd, pfile->deviceoffset, SEEK_SET) != pfile->deviceoffset)
+ pdie("lseek(length reset)", pfile->pname);
+ len += pfile->stat.st_blksize;
+ pfile->endoffset = len;
+ }
+ return pfile->endoffset;
+ } else if (S_ISDIR(pfile->stat.st_mode) || S_ISFIFO(pfile->stat.st_mode) ||
+ S_ISSOCK(pfile->stat.st_mode))
+ die("cannot find size of this device", pfile->pname);
+ else
+ return pfile->stat.st_size;
+}
+
+
+/* Open the named file for read or write, the structure is initialised
+ * appropriately. The name is copied. */
+static void new_mtd(mtd_file *pfile, const char *pname, int fwrite, int fverify, int fd) {
+ pfile->pname = my_strdup(pname);
+ pfile->fwrite = fwrite;
+ pfile->fverify = fverify;
+ pfile->fwritten = 0;
+ pfile->fchanged = 0;
+ pfile->fd = fd;
+
+ if (fstat(fd, &pfile->stat) != 0)
+ pdie("fstat", pname);
+ /* This can be made to work with fifos on read because it is possible
+ * to seek by reading so long as we only seek forward, but it really
+ * isn't worth spending time on this.
+ */
+ if (S_ISDIR(pfile->stat.st_mode) || S_ISFIFO(pfile->stat.st_mode) ||
+ S_ISSOCK(pfile->stat.st_mode))
+ die("invalid device", pname);
+ /* Allow writing to a file for testing - i.e. S_ISREG is fine above. */
+ pfile->cbbuf = pfile->stat.st_blksize;
+ if (pfile->cbbuf == 0)
+ pfile->cbbuf = 4096;
+ pfile->useroffset = 0;
+ pfile->bufferoffset = 0;
+ pfile->deviceoffset = 0;
+ pfile->pbuf = 0;
+ pfile->pwritebuf = 0;
+}
+
+static void open_mtd(mtd_file *pfile, const char *pname, int fwrite, int fverify) {
+ int fd = open(pname, (fwrite && !fverify) ? O_RDWR : O_RDONLY);
+ if (fd < 0)
+ pdie("open", pname);
+ else if (fd < 3)
+ die("no standard streams", "-");
+ new_mtd(pfile, pname, fwrite, fverify, fd);
+}
+
+
+/* Do the actual write. Any pending write buffers are checked and output
+ * to the device. Happens on close and can be called before. Does not
+ * do an fsync. The fwritten flag indicates that write_mtd needs to be
+ * called, the fchanegd flag indicates that something has been written and
+ * an fdatasync needs to happen before the close.
+ */
+static void write_mtd(mtd_file *pfile) {
+ if (pfile->fwritten) {
+ size_t count = pfile->deviceoffset - pfile->bufferoffset;
+ unsigned char *pbuf = pfile->pwritebuf;
+
+ assert(pfile->pbuf != 0);
+ assert(pbuf != 0);
+ assert(pfile->deviceoffset > pfile->bufferoffset);
+ assert(pfile->deviceoffset <= pfile->bufferoffset + pfile->cbbuf);
+ /* If it changed write it. */
+ if (memcmp(pfile->pbuf, pbuf, count) != 0) {
+ /* If verifying the verify just failed... */
+ if (pfile->fverify)
+ die("verification failed", pfile->pname);
+
+ /* So write the whole of this buffer back. Do not do a sync here
+ * because that would force a complete write of the flash erase
+ * block - not good.
+ */
+ if (lseek(pfile->fd, pfile->bufferoffset, SEEK_SET) != pfile->bufferoffset)
+ pdie("lseek(write)", pfile->pname);
+ /* write, well, you have to keep doing it until it works, you
+ * also have to RTFM several times to get this write, so if
+ * this looks wrong please fix it. No, not that, that was
+ * deliberate.
+ */
+ do {
+ ssize_t cb = write(pfile->fd, pbuf, count);
+ assert(cb != 0);
+ assert(cb <= count);
+ if (cb < 0) switch (errno) {
+ case EINTR: /* shall we try that again then? */
+ /* This is the common case - this does happen, it is
+ * necessary to deal with it and it is sufficient to
+ * try again.
+ */
+ break;
+ case EAGAIN: /* what, oh well, if at once you don't succeed. */
+ /* We didn't say O_NONBLOCK above so this should never
+ * happen, however it has. The code will therefore go into
+ * a tight loop in the manner of a certain Scottish nobleman.
+ */
+ break;
+ case EPIPE: /* you don't love me any more. */
+ /* This is a little difficult, it means we were squirting
+ * data down a pipe, so somehow someone has managed to work
+ * out both how to create a named pipe and how much fun to
+ * have by passing it to this program on the command line,
+ * then they have worked out how to make the shell ignore
+ * SIGPIPE in a spawned program (possible with some shells)
+ * then they want to see the really dumb message that comes
+ * out as a result. We just say no.
+ */
+ exit(1);
+ default:
+ pdie("write", pfile->pname);
+ } else {
+ count -= cb;
+ /* It is now necessary to fdatasync this file descriptor
+ * to ensure that this data really does get to its final
+ * destination. (Note that even this is probably not certain
+ * if the destination is a disk with a RAM buffer - which
+ * means *any* disk these days.)
+ */
+ pfile->fchanged = 1;
+ /* Something has been written to flash, but not everything
+ * has (necessarily) been written yet, so if something goes
+ * wrong after this point we are in deep, deep, trouble.
+ */
+ error_level = 3;
+ }
+ } while (count > 0);
+
+ /* So now the device matches the write buffer and the device
+ * pointer is back where it was before.
+ */
+ memcpy(pfile->pbuf, pfile->pwritebuf, pfile->deviceoffset-pfile->bufferoffset);
+ }
+ /* Nothing remains to write from this buffer (hence nothing at all
+ * for this device.)
+ */
+ pfile->fwritten = 0;
+ }
+}
+
+
+/* Close the file, if anything was written out does an fsync.
+ */
+static void close_mtd(mtd_file *pfile) {
+ write_mtd(pfile);
+ assert(!pfile->fwritten);
+ if (pfile->pbuf != 0) {
+ free(pfile->pbuf);
+ pfile->pbuf = 0;
+ }
+ if (pfile->pwritebuf != 0) {
+ free(pfile->pwritebuf);
+ pfile->pwritebuf = 0;
+ }
+ if (pfile->fd >= 0) {
+ /* For a write file be very very careful. For read ignore errors:
+ * it is more important to successfully write than to whine about
+ * strange close errors from a file we don't care about. For a
+ * write file with nothing written we don't care either.
+ */
+ if (pfile->fchanged) {
+ /* This is the all important bit. Doing the fdatasync is what
+ * flushes the data to the flash. If this isn't done there is
+ * no guarantee that close will detect a write error, 'cause the
+ * flash may not have completed the write before the close
+ * returns.
+ */
+ if (fdatasync(pfile->fd) != 0) {
+ /* Trying an fdatasync on a pipe, etc, is silly, but we do
+ * it anyway. EROFS means we just tried to write to a
+ * read only file system, safe but still an error.
+ */
+ if (errno != EINVAL)
+ pdie("sync", pfile->pname);
+ }
+ if (close(pfile->fd) != 0)
+ pdie("close", pfile->pname);
+ } else
+ (void)close(pfile->fd);
+ pfile->fd = (-1);
+ }
+ if (pfile->pname != 0) {
+ free(pfile->pname);
+ pfile->pname = 0;
+ }
+ init_mtd(pfile);
+}
+
+
+/* Obtain an input and, if necessary, an output buffer. */
+static void buffer_mtd(mtd_file *pfile) {
+ if (pfile->pbuf == 0) {
+ size_t blksize = pfile->cbbuf;
+ assert(blksize > 0);
+ assert(pfile->pwritebuf == 0);
+
+ /* Get blksize bytes (note: things could be speeded up by aligning
+ * the buffer but this really doesn't matter, all the time goes in
+ * read/write of the flash!)
+ */
+ pfile->pbuf = malloc(blksize);
+ if (pfile->fwrite)
+ pfile->pwritebuf = malloc(blksize);
+ if (pfile->pbuf == 0 || (pfile->fwrite && pfile->pwritebuf == 0))
+ die("out of memory", pfile->pname);
+ }
+}
+
+
+/* Read some data including the current user position. This will also *write* data
+ * if something is waiting to be written.
+ *
+ * NOTE: in the original design I conceived of some scheme whereby all the writes
+ * would be buffered up for the end, but I can't see how this would actually help
+ * anything because even if data has to be read from the device to determine read
+ * locations it tends to happen before the relevant writes. In the access patterns
+ * I know (they are very simple - and that is important in itself) there is never
+ * a need to read from a write device.
+ */
+static void read_mtd(mtd_file *pfile) {
+ size_t cbread;
+ int ioffset;
+
+ /* 'useroffset' is where we need to read from, 'deviceoffset' is where we are
+ * at (sic) and 'bufferoffset'..'deviceoffset' is what we have already.
+ */
+ if (pfile->useroffset >= pfile->bufferoffset &&
+ pfile->useroffset < pfile->deviceoffset)
+ return;
+
+ if (pfile->useroffset < 0 || pfile->useroffset >= size_mtd(pfile))
+ die("read outside file", pfile->pname);
+
+ /* Make sure there is a buffer. */
+ buffer_mtd(pfile);
+
+ /* This is the maximum amount which can be read. */
+ cbread = pfile->cbbuf;
+ if (pfile->useroffset >= pfile->bufferoffset &&
+ pfile->useroffset < pfile->bufferoffset + cbread) {
+ /* Just fill the rest of the buffer. */
+ ioffset = pfile->deviceoffset - pfile->bufferoffset;
+
+ assert(pfile->deviceoffset < pfile->bufferoffset + cbread);
+ cbread -= ioffset;
+ } else {
+ off_t base;
+
+ /* We to move the buffer therefore any pending write needs to be flushed. */
+ write_mtd(pfile);
+ assert(!pfile->fwritten);
+
+ /* Seek to the aligned buffer boundary if necessary. */
+ base = (pfile->useroffset / cbread) * cbread;
+ if (base != pfile->deviceoffset) {
+ if (lseek(pfile->fd, base, SEEK_SET) != base)
+ pdie("lseek(read)", pfile->pname);
+ pfile->deviceoffset = base;
+ }
+ pfile->bufferoffset = base;
+ ioffset = 0;
+ }
+
+ /* Reading is like writing, EINTR can stop it succeeding but is a
+ * continuable error.
+ */
+ assert(pfile->bufferoffset <= pfile->useroffset);
+ assert(pfile->useroffset < pfile->bufferoffset + cbread);
+ assert(pfile->deviceoffset <= pfile->useroffset);
+ do {
+ ssize_t cb = read(pfile->fd, pfile->pbuf+ioffset, cbread);
+ if (cb < 0) switch (errno) {
+ case EINTR: /* simple restart */
+ /* POSIX allows this to happen when something has been
+ * read. Reset the file pointer just in case.
+ */
+ if (lseek(pfile->fd, pfile->deviceoffset, SEEK_SET) != pfile->deviceoffset)
+ pdie("lseek(read reset)", pfile->pname);
+ break;
+ case EAGAIN: /* O_NONBLOCK on the input? */
+ break;
+ default:
+ pdie("read", pfile->pname);
+ } else if (cb == 0) {
+ die("unexpected end of file", pfile->pname);
+ } else {
+ /* Save a copy of the data so that it can be written out again
+ * by a write file.
+ */
+ if (pfile->pwritebuf != 0)
+ memcpy(pfile->pwritebuf+ioffset, pfile->pbuf+ioffset, cb);
+ cbread -= cb;
+ ioffset += cb;
+ pfile->deviceoffset += cb;
+ }
+ } while (cbread > 0 && pfile->useroffset >= pfile->deviceoffset);
+
+ assert(pfile->useroffset < pfile->deviceoffset);
+}
+
+
+/* Basic IO - these are the functions to use, not the internal read/write
+ * functions above.
+ */
+/* Set the current read/write pointer on this file. */
+#if 0 /*UNUSED*/
+static void mtd_seek(mtd_file *pfile, off_t offset) {
+ pfile->useroffset = offset;
+}
+#endif
+
+
+/* Get a single byte (returned) and advance the read pointer by one. */
+static unsigned char mtd_getb(mtd_file *pfile) {
+ read_mtd(pfile);
+ return (pfile->fwrite ? pfile->pwritebuf : pfile->pbuf)[
+ pfile->useroffset++ - pfile->bufferoffset];
+}
+
+
+/* Store a single byte in a write file and advance the pointer by one. */
+static void mtd_putb(mtd_file *pfile, unsigned long b) {
+ if (!pfile->fwrite)
+ die("file is not writeable", pfile->pname);
+ read_mtd(pfile);
+ if (b != pfile->pwritebuf[pfile->useroffset-pfile->bufferoffset]) {
+ pfile->pwritebuf[pfile->useroffset-pfile->bufferoffset] = b;
+ pfile->fwritten = 1;
+ }
+ ++(pfile->useroffset);
+}
+
+
+/* Read a given number of bytes, which must exist in the file, and
+ * advance the pointer by that amount.
+ */
+static void mtd_readbytes(mtd_file *pfile, unsigned char *pbuf, size_t cb) {
+ if (pfile->useroffset+cb > size_mtd(pfile))
+ die("read beyond end of file", pfile->pname);
+
+ while (cb > 0) {
+ int cbavail;
+
+ read_mtd(pfile);
+ cbavail = pfile->deviceoffset - pfile->useroffset;
+ assert(cbavail > 0 && cbavail <= pfile->cbbuf);
+ if (cbavail > cb)
+ cbavail = cb;
+
+ assert(pfile->useroffset >= pfile->bufferoffset);
+ assert(pfile->useroffset < pfile->deviceoffset);
+ assert(pfile->deviceoffset <= pfile->bufferoffset + pfile->cbbuf);
+
+ memcpy(pbuf, (pfile->fwrite ? pfile->pwritebuf : pfile->pbuf) +
+ (pfile->useroffset-pfile->bufferoffset), cbavail);
+ pfile->useroffset += cbavail;
+ pbuf += cbavail;
+ cb -= cbavail;
+ }
+}
+
+
+/* Write a given number of bytes and advance the pointer. As with readbytes
+ * the bytes must already exist in the file - mtd_file will never extend the
+ * file only change existing bytes.
+ */
+static void mtd_writebytes(mtd_file *pfile, const unsigned char *pbuf, size_t cb) {
+ if (!pfile->fwrite)
+ die("file is not writeable", pfile->pname);
+ if (pfile->useroffset+cb > size_mtd(pfile))
+ die("write beyond end of file", pfile->pname);
+ while (cb > 0) {
+ int cbavail;
+
+ /* This may look strange but it is correct - this code always reads
+ * before it writes to avoid unnecessary writes.
+ */
+ read_mtd(pfile);
+ cbavail = pfile->deviceoffset - pfile->useroffset;
+ if (cbavail > cb)
+ cbavail = cb;
+ memcpy(pfile->pwritebuf + (pfile->useroffset-pfile->bufferoffset), pbuf, cbavail);
+ pfile->fwritten = 1;
+ pfile->useroffset += cbavail;
+ pbuf += cbavail;
+ cb -= cbavail;
+ }
+}
+
+
+#if 0 /* Commented out because I don't think this is worth while. */
+/* Copy bytes from the pointer in one file to the pointer in another
+ * file (avoids an intermediate buffer compared to readbytes/writebytes.)
+ */
+static void mtd_copy(mtd_file *pto, mtd_file *pfrom, size_t cb) {
+ int cbfrom, cbto;
+
+ if (!pto->fwrite)
+ die("file is not writeable", pto->pname);
+ if (pto->useroffset+cb > size_mtd(pto))
+ die("write beyond end of file", pto->pname);
+ if (pfrom->useroffset+cb > size_mtd(pfrom))
+ die("read beyond end of file", pfrom->pname);
+ /* Copying from and to the same place has no effect. */
+ if (pfrom == pto)
+ return;
+
+ cbfrom = cbto = 0;
+ while (cb > 0) {
+ int cbavail;
+
+ if (cbfrom <= 0) {
+ read_mtd(pfrom);
+ cbfrom = pfrom->deviceoffset - pfrom->useroffset;
+ compared to readbytes/writebytes}
+ if (cbto <= 0) {
+ read_mtd(pto);
+ cbto = pto->deviceoffset - pto->useroffset;
+ }
+
+ /* Take the smallest byte count and copy it. */
+ cbavail = cbfrom;
+ if (cbavail > cbto)
+ cbavail = cbto;
+ if (cbavail > cb)
+ cbavail = cb;
+
+ memcpy(pto->pwritebuf + (pto->useroffset-pto->bufferoffset),
+ pfrom->pbuf + (pfrom->useroffset-pfrom->bufferoffset),
+ cbavail);
+ pto->fwritten = 1;
+
+ pto->useroffset += cbavail;
+ cbto -= cbavail;
+ pfrom->useroffset += cbavail;
+ cbfrom -= cbavail;
+
+ cb -= cbavail;
+ }
+}
+#endif
+
+
+/***********************************************************************
+ * parse
+ *
+ * Parse a command line option or a single line. See the help below
+ * for details...
+ ***********************************************************************/
+#define STACK_BASE 8
+#define STACK_SIZE 256
+#define NUM_FILES 16
+typedef struct parse_buf {
+ int fverify; /* Just verifying, do no write. */
+ int cstack;
+ int fbreak; /* Break in an expression. */
+ mtd_file* pfrom;
+ mtd_file* pto;
+
+ /* The buffers. */
+ unsigned long variables[256];
+ unsigned long stack[STACK_SIZE];
+ mtd_file files[NUM_FILES];
+} parse_buf;
+
+
+/* Initialiser. */
+static void init_parse(parse_buf *pp, int fverify) {
+ int i;
+ memset(pp, 0, sizeof *pp);
+ pp->fverify = fverify;
+ pp->cstack = STACK_BASE;
+ pp->fbreak = 0;
+ pp->pfrom = 0;
+ pp->pto = 0;
+ for (i=0; i<NUM_FILES; ++i)
+ init_mtd(pp->files+i);
+}
+
+
+/* Terminator. */
+static void quit(parse_buf *pp, int exit_code) __attribute__((noreturn));
+static void quit(parse_buf *pp, int exit_code) {
+ int i;
+ /* Close all the files. */
+ for (i=0; i<NUM_FILES; ++i)
+ if (pp->files[i].pname != 0)
+ close_mtd(pp->files+i);
+
+ /* And make sure the output worked too. */
+ if (fflush(stdout) == EOF || ferror(stdout) || fclose(stdout) == EOF)
+ pdie("output failed", "stdout");
+
+ exit(exit_code);
+}
+
+
+/* Input a single byte. */
+static unsigned char inb(parse_buf *pp) {
+ int b;
+ if (pp->pfrom == 0) {
+ b = getchar();
+ if (b == EOF)
+ pdie("read error", "stdin");
+ } else {
+ b = mtd_getb(pp->pfrom);
+ }
+ return b;
+}
+
+
+/* Output a single byte. */
+static void outb(parse_buf *pp, unsigned long b) {
+ if (pp->pto == 0) {
+ if (putchar(b) == EOF)
+ pdie("write error", "stdout");
+ } else {
+ mtd_putb(pp->pto, b);
+ }
+}
+
+
+/* Output these bytes. */
+static void outputbytes(parse_buf *pp, const char *pbuf, size_t cb) {
+ if (pp->pto == 0) {
+ if (fwrite(pbuf, cb, 1, stdout) != 1)
+ pdie("write error", "stdout");
+ } else
+ mtd_writebytes(pp->pto, pbuf, cb);
+}
+
+/* Copy a stream of bytes. */
+static void copybytes(parse_buf *pp, size_t cb) {
+ while (cb > 0) {
+ size_t cbavail = cb;
+ unsigned char buf[1024];
+ if (cbavail > sizeof buf)
+ cbavail = sizeof buf;
+ if (pp->pfrom == 0) {
+ if (fread(buf, cbavail, 1, stdin) != 1)
+ pdie("read error", "stdin");
+ } else
+ mtd_readbytes(pp->pfrom, buf, cbavail);
+
+ outputbytes(pp, buf, cbavail);
+
+ cb -= cbavail;
+ }
+}
+
+
+/* Fill the output with a count of bytes of a given value. */
+static void fillbytes(parse_buf *pp, unsigned long val, size_t cb) {
+ unsigned char buf[1024];
+ memset(buf, val, sizeof buf);
+
+ while (cb > 0) {
+ size_t cbavail = cb;
+ if (cbavail > sizeof buf)
+ cbavail = sizeof buf;
+
+ outputbytes(pp, buf, cbavail);
+
+ cb -= cbavail;
+ }
+}
+
+
+/* Push a single numeric value onto the stack. */
+static void push(parse_buf *pp, unsigned long num, const unsigned char *str) {
+ if (pp->cstack >= STACK_SIZE)
+ die("stack overflow", str);
+ pp->stack[pp->cstack++] = num;
+}
+
+
+/* Pop one or move variables. */
+static void pop(parse_buf *pp, int num, const unsigned char *str) {
+ if (pp->cstack < STACK_BASE+num)
+ die("stack underflow", str);
+ pp->cstack -= num;
+}
+
+/* Return (and pop) the top of stack. */
+static unsigned long top(parse_buf *pp, const unsigned char *str) {
+ if (pp->cstack <= STACK_BASE)
+ die("stack underflow", str);
+ return pp->stack[--(pp->cstack)];
+}
+
+
+/* Store the result of an operator. */
+static void op(parse_buf *pp, int numpop, unsigned long num,
+ const unsigned char *str) {
+ pop(pp, numpop, str);
+ push(pp, num, str);
+}
+
+
+/* Parse a single expression, which may be empty. The conditional execution
+ * stuff is identical to that for a command except that (:?) are used instead
+ * of $($:$?$)
+ */
+static int parse_expression(parse_buf *pp, const unsigned char *line, int Ac, int AcEnd) {
+ int SP = 0, fnoexec = 0, test = 0;
+ int stack[16];
+
+ for (;Ac<AcEnd;++Ac) {
+ const unsigned char *lp = line+Ac;
+ unsigned char ch = *lp;
+ switch (ch) {
+ /* Control flow. These operators have to explicitly check
+ * the fnoexec state because they manipulate it.
+ */
+ case '(': /* if */
+ if (SP >= 16)
+ die("() stack overflow", lp);
+ stack[SP++] = Ac;
+ if (fnoexec) {
+ fnoexec += 3;
+ } else {
+ fnoexec = top(pp, lp) == 0;
+ }
+ break;
+
+ case '[': /* test start */
+ /* If fnoexec >= 3 the whole block is disabled. */
+ if (fnoexec <= 2) {
+ /* Valid only inside an () block and there should only
+ * be one active at once.
+ */
+ if (test != 0 || SP <= 0)
+ goto badnest;
+ /* Record the start of the test. */
+ test = Ac+1;
+ /* If the previous block executed record this. */
+ if (fnoexec == 0)
+ fnoexec = 2;
+ }
+ break;
+
+ case ':': /* elif */
+ /* fnoexec is 1 if nothing has executed in this block yet,
+ * and if the block itself is executing, it is 2 if something
+ * did execute, it is >2 for a non-executed block, including
+ * one with a break.
+ */
+ if (fnoexec <= 2) {
+ if (test == 0 || SP <= 0)
+ goto badnest;
+
+ assert(fnoexec > 0);
+ assert(!pp->fbreak);
+ /* 1: nothing has executed yet.
+ * 2: an if or elif has executed.
+ */
+ if (fnoexec == 1) {
+ /* Parse the test. If this results in a break no
+ * condition is popped from the stack, otherwise
+ * the condition which the expression should push
+ * is popped.
+ */
+ (void)parse_expression(pp, line, test, Ac);
+ if (pp->fbreak) {
+ fnoexec = 3;
+ pp->fbreak = 0;
+ } else
+ fnoexec = top(pp, lp) == 0;
+ }
+
+ /* And the test has been consumed. */
+ test = 0;
+ }
+ break;
+
+ case ')': /* end+loop if */
+ /* The stack must always be popped. */
+ if (SP <= 0)
+ goto badnest;
+ --SP;
+ /* If fnoexec>2 then this is a nested disabled block or, in
+ * the case of 3, a break. In neither case is the expression
+ * evaluated and the test setting is for an enclosing block.
+ */
+ if (fnoexec > 2) {
+ fnoexec -= 3;
+ } else {
+ /* In this case there must be a test. */
+ if (test == 0)
+ goto badnest;
+
+ /* Execution resumes regardless. */
+ fnoexec = 0;
+ assert(!pp->fbreak);
+
+ /* So make the loop test now - this may cause a branch back
+ * to the ( and that will push the stack again. Evaluate
+ * the test.
+ */
+ (void)parse_expression(pp, line, test, Ac);
+ if (pp->fbreak)
+ pp->fbreak = 0;
+ else if (top(pp, lp) != 0) {
+ Ac = stack[SP]-1; /* Ac is incremented below */
+ }
+
+ /* And the test has been consumed. */
+ test = 0;
+ }
+ break;
+
+ badnest:
+ die("bad [: or [) nesting", lp);
+ break;
+
+ case ';':
+ case '\n':
+ /* end of line terminates the loop, but Ac is stepped beyond the
+ * terminator.
+ */
+ ++Ac;
+ goto end;
+
+ case ' ':
+ case '\f':
+ case '\r':
+ case '\t':
+ case '\v':
+ case ',': /* Treat as a space */
+ /* Skip other white space. */
+ break;
+
+ /* Everything else is glommed together because the fnoexec case
+ * can be simply handled by skipping character-by-character (because
+ * (:?); do not occur inside numbers!)
+ */
+ default:
+ if (fnoexec)
+ break;
+
+ if (isupper(ch))
+ push(pp, pp->variables[ch], lp);
+ else if (isdigit(ch)) {
+ char *end = (char*)lp;
+ unsigned long num;
+ errno = 0;
+ num = strtoul(lp, &end, 0);
+ if (num == ULONG_MAX && (errno == EINVAL || errno == ERANGE))
+ pdie("invalid number", lp);
+ push(pp, num, lp);
+ /* strotul returns a pointer to the first invalid character in
+ * end, so Ac becomes end-line-1, because it is incremented below.
+ */
+ Ac = (const unsigned char*)end-line-1;
+ } else {
+ /* The operators are handled here. An unrecognised character is an
+ * error at this point. The left, right are always valid because
+ * the stack has 8 unused slots at the top...
+ */
+ unsigned long left = pp->stack[pp->cstack - 2];
+ unsigned long right = pp->stack[pp->cstack - 1];
+
+ switch (ch) {
+ case '?': /* break */
+ /* break inside a condition is actually allowed, so this may
+ * happen with SP==0 while evaluating a condition. For the
+ * moment ? is also allowed outside a loop, it terminates the
+ * processing of the whole expression.
+ */
+ if (top(pp, lp) != 0) {
+ /* break: skip to the ) and do not do the test on
+ * that either.
+ */
+ fnoexec = 3;
+ }
+ break;
+
+ #define DIOP(operator) op(pp, 2, left operator right, lp); break
+ #define MONOP(operator) op(pp, 1, operator right, lp); break
+ /* The C operators */
+ case '*': DIOP(*);
+ case '+': DIOP(+);
+ case '-': DIOP(-);
+ case '/': DIOP(/);
+ case '%': DIOP(%);
+ case '<': DIOP(<);
+ case '>': DIOP(>);
+ case '|': DIOP(|);
+ case '&': DIOP(&);
+ case '^': DIOP(^);
+ case '~': MONOP(~);
+ case '!': MONOP(!);
+ case '=': /* equality */
+ op(pp, 2, left == right, lp);
+ break;
+ case '{': /* shift left */
+ op(pp, 2, left << right, lp);
+ break;
+ case '}': /* shift right */
+ op(pp, 2, left >> right, lp);
+ break;
+ case 'r': /* rotate right */
+ op(pp, 2, (left >> right) + (left << (32-right)), lp);
+ break;
+ case 'e': /* sign extend (right is number of valid bits). */
+ op(pp, 2, (long)(left << (32-right)) >> (32-right), lp);
+ break;
+ case 'm': /* mask (right is number of valid bits). */
+ op(pp, 2, (left << (32-right)) >> (32-right), lp);
+ break;
+ case '$': /* Size of input. */
+ if (pp->pfrom == 0)
+ die("size of input unknown", lp);
+ push(pp, size_mtd(pp->pfrom), lp);
+ break;
+ case 'f': /* position of input ('from' pointer). */
+ if (pp->pfrom == 0)
+ die("position of input unknown", lp);
+ push(pp, pp->pfrom->useroffset, lp);
+ break;
+ case '#': /* Size of output. */
+ if (pp->pto == 0)
+ die("size of output unknown", lp);
+ push(pp, size_mtd(pp->pto), lp);
+ break;
+ case 't': /* position of output ('to' pointer). */
+ if (pp->pto == 0)
+ die("position of output unknown", lp);
+ push(pp, pp->pto->useroffset, lp);
+ break;
+ case 'd': /* device number of the input device */
+ if (pp->pfrom == 0)
+ die("input device number unknown", lp);
+ push(pp, pp->pfrom->stat.st_rdev == 0 ? pp->pfrom->stat.st_dev :
+ pp->pfrom->stat.st_rdev, lp);
+ break;
+ case '@': /* one byte read. */
+ push(pp, inb(pp), lp);
+ break;
+ case 'b': /* big endian 4 byte read. */
+ #define P(st) (void)parse_expression(pp, st, 0, (sizeof st)-1)
+ P("@8{@+8{@+8{@+;# 4 byte big-endian read");
+ break;
+ case 'l': /* little endian 4 byte read. */
+ P("@@@@8{+8{+8{+;# 4 byte little-endian read");
+ break;
+ case '.': /* copy (dup) */
+ push(pp, right, lp);
+ break;
+ case 'p': /* pop */
+ pop(pp, 1, lp);
+ break;
+ case 's': /* swap (top two elements of the stack) */
+ pop(pp, 2, lp);
+ push(pp, right, lp);
+ push(pp, left, lp);
+ break;
+ default:
+ die("invalid operator", lp);
+ }
+ }
+ }
+ }
+
+ /* Here on terminator or Ac==AcEnd. */
+end:
+ /* If SP>0 then there was some bad nesting going on - i.e. the brackets have
+ * not been closed. fnoexec must be zero if SP is 0.
+ */
+ if (SP > 0)
+ die("unclosed ( )", line);
+ assert(fnoexec == 0 || fnoexec == 3);
+ if (fnoexec == 3)
+ pp->fbreak = 1;
+ return Ac;
+}
+
+
+/* Parse an expression and return numbers off the top of stack. */
+static int need(parse_buf *pp, unsigned long arg[2],
+ const unsigned char *line, int Ac, int AcEnd, int num) {
+ int Acnew = parse_expression(pp, line, Ac, AcEnd);
+
+ assert(num <= 2);
+ if (pp->cstack < STACK_BASE+num)
+ die("too few arguments", line+Ac);
+
+ while (num > 0)
+ arg[--num] = pp->stack[--(pp->cstack)];
+
+ /* cancel a break at the top level. */
+ pp->fbreak = 0;
+ return Acnew;
+}
+
+
+/* Parse a string. The string ends up in the buffer and is limited in
+ * size to STR_MAX. The API returns a null string for empty quoted
+ * strings and for the unquoted case where there is only whitespace
+ * in the rest of the command. The result is the index of the first
+ * character after the end of the command (*not* the end of the string.)
+ */
+static int string(unsigned char *buffer, const unsigned char *line, int Ac) {
+ int start, end;
+
+ while (isspace(line[Ac]) && line[Ac] != '\n') ++Ac;
+
+ if (line[Ac] == '"' || line[Ac] == '\'') {
+ const unsigned char quote = line[Ac];
+ start = Ac;
+ end = Ac+1;
+ while (line[end] != 0 && line[end] != '\n' && line[end] != quote) ++end;
+ if (line[end] != quote)
+ die("unterminated quoted string", line+start);
+ Ac = end+1;
+ while (isspace(line[Ac]) && line[Ac] != '\n') ++Ac;
+ if (line[Ac] != 0 && line[Ac] != ';' && line[Ac] != '\n')
+ die("stuff on line after quoted string", line+start);
+ ++start;
+ } else {
+ start = Ac;
+ while (line[Ac] != 0 && line[Ac] != ';' && line[Ac] != '\n') ++Ac;
+ end = Ac;
+ }
+
+ end -= start;
+ if (end >= STR_MAX)
+ die("string too long", line+start);
+
+ /* Copy out the string into the buffer and null terminate it. */
+ memcpy(buffer, line+start, end);
+ buffer[end] = 0;
+
+ /* Skip over EOL, if present, and store the string pointer back. */
+ if (line[Ac] != 0) ++Ac;
+ return Ac;
+}
+
+
+/* Find the end of line, Ac always points to the start. */
+static int eol(const unsigned char *line, int Ac) {
+ unsigned char quote = 0;
+ while (line[Ac] != '\n' && (line[Ac] != ';' || quote)) {
+ if (line[Ac] == 0)
+ return Ac;
+ if (line[Ac] == '"' || line[Ac] == '\"') {
+ if (quote == 0)
+ quote = line[Ac];
+ else if (quote == line[Ac])
+ quote = 0;
+ }
+ ++Ac;
+ }
+ return Ac+1;
+}
+
+
+/* Find a file given its name. */
+static mtd_file *find_file(parse_buf *pp, const unsigned char *name) {
+ int i;
+ for (i=0; i<NUM_FILES; ++i) {
+ if (pp->files[i].pname != 0 &&
+ strcmp(name, pp->files[i].pname) == 0)
+ return pp->files+i;
+ }
+ return 0;
+}
+
+
+/* Open a file for read or write. */
+static mtd_file *open_file(parse_buf *pp, const unsigned char *name, int fwrite) {
+ int i;
+ for (i=0; i<NUM_FILES; ++i)
+ if (pp->files[i].pname == 0)
+ break;
+ if (i >= NUM_FILES)
+ die("no more files", name);
+ open_mtd(pp->files+i, name, fwrite, pp->fverify);
+ return pp->files+i;
+}
+
+
+/* Basic parse function. Does all the work. Simple line-by-line command
+ * parser. The input is a vector of strings (an argv), 'input' says where
+ * it came from.
+ */
+static void parse(parse_buf *pp, int lines, const char **prog) {
+ /* The program pointer is a line index Al and a character within the
+ * line Ac. The exec stack just has those references (i.e. (Al,Ac)
+ * is a PC).
+ */
+ int Al = 0, SP = 0, fnoexec = 0;
+ struct stack {
+ int Al, Ac;
+ } stack[16];
+
+ /* fnoexec has these values:
+ * 0: normal execution
+ * 1: within an if $($:$) and none of the tests have passed (so
+ * nothing has been executed in this block.)
+ * 2: within an if and a test has passed (a previous block has
+ * been executed.)
+ * 3: within an if and a break ($?) has succeeded, execute nothing
+ * until *and including* the $) (i.e. do not evaluate the value
+ * on that either.)
+ * This applies to nested if blocks too when the block is executable.
+ * If a block is nested within a non-executing environment the $(
+ * adds 3 to fnoexec. The $) always subtracts 3 unless fnoexec is
+ * 0, 1, 2 or 3 thus the prior state is reliably restored.
+ */
+
+ while (Al < lines) {
+ int Ac = 0;
+ const unsigned char *line = prog[Al];
+ const int AcEnd = strlen(line);
+
+ while (line[Ac]) {
+ const unsigned char *lp = line+Ac;
+ unsigned char ch = *lp;
+
+ /* A command is two characters, except that ';' is end-of-line,
+ * skip these things until we see a command, then use the next
+ * two characters. line[Ac] != 0 so the read of Ac+1 is safe.
+ */
+ if (isspace(ch) || ch == ';') {
+ ++Ac;
+ } else if ((ch != '$' && fnoexec) || ch == '#') {
+ /* disabled execution and not a control flow command, or
+ * a comment.
+ */
+ Ac = eol(line, Ac);
+ } else switch ((ch << 8) + line[Ac+1]) {
+ unsigned long arg[2];
+ unsigned char buffer[STR_MAX];
+
+ /* Control flow. These commands have to explicitly check
+ * the fnoexec state because they manipulate it.
+ */
+ #define CASE(l,r) case (((l)<<8)+(r))
+ CASE('$','('): /* if */
+ if (SP >= 16)
+ die("exec stack overflow", lp);
+ stack[SP].Al = Al;
+ stack[SP++].Ac = Ac;
+ if (fnoexec) {
+ fnoexec += 3;
+ goto noexec;
+ }
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ fnoexec = arg[0] == 0;
+ break;
+
+ CASE('$',':'): /* elif */
+ /* fnoexec is 1 if nothing has executed in this block yet,
+ * and if the block itself is executing.
+ */
+ if (SP <= 0)
+ goto underflow;
+ if (fnoexec != 1) {
+ /* If the previous block executed record this. */
+ if (fnoexec == 0)
+ fnoexec = 2;
+ goto noexec;
+ }
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ fnoexec = arg[0] == 0;
+ break;
+
+ CASE('$',')'): /* end+loop if */
+ /* The stack must always be popped. */
+ if (SP <= 0)
+ goto underflow;
+ --SP;
+ /* If fnoexec>2 then this is a nested disabled block or, in
+ * the case of 3, a break. In neither case is the expression
+ * evaluated.
+ */
+ if (fnoexec > 2) {
+ fnoexec -= 3;
+ goto noexec;
+ }
+ fnoexec = 0;
+ /* So make the loop test now - this may cause a branch back
+ * to the $( and that will push the stack again.
+ */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ if (arg[0] != 0) {
+ Al = stack[SP].Al;
+ Ac = stack[SP].Ac;
+ /* Do not ever forget this, because we may not exit the
+ * immediately enclosing loop and line is set up outside
+ * it!
+ */
+ line = prog[Al];
+ }
+ break;
+
+ CASE('$','?'): /* break */
+ if (SP <= 0)
+ goto underflow;
+ if (fnoexec)
+ goto noexec;
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ if (arg[0] != 0) {
+ /* break: skip to the $) and do not do the test on
+ * that either.
+ */
+ fnoexec = 3;
+ }
+ break;
+
+ underflow:
+ die("exec stack underflow", lp);
+ noexec:
+ /* Control flow no-exec case. */
+ Ac = eol(line, Ac);
+ break;
+
+ /* Program termination */
+ CASE('!','?'): /* exit if non-zero */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ if (arg[0] != 0)
+ quit(pp, arg[0]);
+ break;
+
+ CASE('!','!'): /* exit unconditionally */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ quit(pp, arg[0]);
+ break;
+
+ /* Input/output */
+ CASE('>','>'): /* write to (no argument reverts to stdout) */
+ Ac = string(buffer, line, Ac+2);
+ if (buffer[0] != 0) {
+ mtd_file *pfile = find_file(pp, buffer);
+ if (pfile == 0)
+ pfile = open_file(pp, buffer, 1);
+ else if (!pfile->fwrite)
+ die("attempt to open a read file for write", buffer);
+ pp->pto = pfile;
+ } else
+ pp->pto = 0;
+ break;
+
+ CASE('<','<'): /* read from */
+ Ac = string(buffer, line, Ac+2);
+ if (buffer[0] != 0) {
+ mtd_file *pfile = find_file(pp, buffer);
+ if (pfile == 0)
+ pfile = open_file(pp, buffer, 0);
+ pp->pfrom = pfile;
+ } else
+ pp->pfrom = 0;
+ break;
+
+ CASE('<','>'): /* close */
+ CASE('>','<'): /* synonym of close */
+ Ac = string(buffer, line, Ac+2);
+ if (buffer[0] != 0) {
+ mtd_file *pfile = find_file(pp, buffer);
+ if (pfile == 0)
+ die("no such file to close", buffer);
+
+ if (pfile == pp->pfrom)
+ pp->pfrom = 0;
+ if (pfile == pp->pto)
+ pp->pto = 0;
+ close_mtd(pfile);
+ } else
+ die("<> (close) requires an argument", lp);
+ break;
+
+ CASE('>','='): /* set to pointer */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ if (pp->pto == 0)
+ die("no output file", lp);
+ pp->pto->useroffset = arg[0];
+ break;
+
+ CASE('<','='): /* set from pointer */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ if (pp->pfrom == 0)
+ die("no input file", lp);
+ pp->pfrom->useroffset = arg[0];
+ break;
+
+ /* writing to output */
+ CASE('w','b'): /* bigendian number bytes */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 2);
+ switch (arg[1]) {
+ case 4: outb(pp, arg[0] >> 24);
+ case 3: outb(pp, arg[0] >> 16);
+ case 2: outb(pp, arg[0] >> 8);
+ case 1: outb(pp, arg[0]);
+ break;
+ default:die("byte count out of range", lp);
+ }
+ break;
+
+ CASE('w','l'): /* little endian number bytes */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 2);
+ switch (arg[1]) {
+ case 4: outb(pp, arg[0]); arg[0] >>= 8;
+ case 3: outb(pp, arg[0]); arg[0] >>= 8;
+ case 2: outb(pp, arg[0]); arg[0] >>= 8;
+ case 1: outb(pp, arg[0]);
+ break;
+ default:die("byte count out of range", lp);
+ }
+ break;
+
+ CASE('w','s'): /* write string */
+ Ac = string(buffer, line, Ac+2);
+ outputbytes(pp, buffer, strlen(buffer));
+ break;
+
+ CASE('f','b'): /* fill bytes */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 2);
+
+ /* The likely error is forgetting an argument, that may
+ * put the byte count into the fill value.
+ */
+ if (arg[1] > 255)
+ die("fill value out of range", lp);
+
+ /* Now call fillbytes, arguments same order as memset, but
+ * the reverse from the command (fb number value).
+ */
+ fillbytes(pp, arg[1], arg[0]);
+ break;
+
+ CASE('c','p'): /* copy bytes */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ copybytes(pp, arg[0]);
+ break;
+
+ /* writing to stdout */
+ CASE('p','r'): /* printf("%lu\n") */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ printf("%lu\n", arg[0]);
+ stdout_check:
+ if (ferror(stdout))
+ pdie("write error", "stdout");
+ break;
+
+ CASE('p','f'): /* printf(string) */
+ Ac = string(buffer, line, Ac+2);
+ /* This flushes the whole stack, so "printf;" can be useful
+ * under some circumstances!
+ */
+ {
+ unsigned long *stack = pp->stack + pp->cstack - 1;
+ pp->cstack = STACK_BASE;
+ printf(buffer, stack[0], stack[-1], stack[-2], stack[-3],
+ stack[-4], stack[-5], stack[-6], stack[-7]);
+ }
+ goto stdout_check;
+
+ CASE('p','n'): /* printf("\n") */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 0);
+ printf("\n");
+ goto stdout_check;
+
+
+ CASE('.','='): /* eval */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 0);
+ break;
+
+ default:
+ /* Assignment is handled here. */
+ if (isupper(ch) && line[Ac+1] == '=') {
+ /* Assignment. */
+ Ac = need(pp, arg, line, Ac+2, AcEnd, 1);
+ pp->variables[ch] = arg[0];
+ } else
+ die("unknown command", lp);
+ break;
+ }
+ }
+
+ /* end of line (line[Ac] is '\0'), move to the next line. */
+ ++Al;
+ }
+
+ /* If SP>0 then there was some bad nesting going on - i.e. the brackets have
+ * not been closed. fnoexec must be zero if SP is 0.
+ */
+ if (SP > 0)
+ die("unclosed $( $)", "eof");
+ assert(fnoexec == 0);
+}
+
+/* The command only understands two options, -v for verify and -h for
+ * help.
+ */
+int main(int argc, const char **argv) {
+ int i = 0;
+ parse_buf p;
+
+ /* the option must be the first argument. */
+ if (argc < 2 || strcmp(argv[1], "-h") == 0) {
+ fprintf(stderr, "%s: usage: %s ([-v] {comands} |-h [command])\n", argv[0], argv[0]);
+#if HELP
+ if (argc < 3) {
+ fprintf(stderr, " options:\n"
+ " -v: do not write, just verify a previous write\n"
+ " -h: output this help\n"
+ " -h commands: output command help\n"
+ " -h <command>: output help for command <command>\n");
+ } else {
+ for (i=2; i<argc; ++i) {
+ const unsigned char *p = argv[i];
+ switch ((argv[i][0] << 8) + argv[i][1]) {
+ CASE('a','d'):
+ p = "Enter the keyword in [] contained after the command list\n"
+ "for more information about those commands";
+ break;
+ CASE('c','o'):
+ if (argv[i][2] != 'n')
+ p = " commands are terminated by ';', newline or the end of input:\n"
+ " <command> {arguments} ;\n\n"
+ " command: a two character command: [additional info]\n"
+ " conditional execution: $( $: $? $) [conditional]\n"
+ " program termination: !? !! [exit]\n"
+ " input/output control: >> << <> >= <= [io]\n"
+ " writing to the output: wb wl ws fb cp [write]\n"
+ " writing to stdout: pr pf pn [messages]\n"
+ " assignment: <C>= .= [assign]\n"
+ " comment: #\n\n"
+ " -h <command>: output the syntax of command <command>\n\n"
+ " arguments: a string or a postfix numeric expression\n"
+ " -h string: output the syntax of a string argument\n"
+ " -h number: output the syntax of a numeric argument\n"
+ " -h operator: output a summary of the operators\n\n"
+ " A command which starts with '#' is ignored (a comment).";
+ else
+ p = "conditional evalation\n"
+ " Conditional evalation has the general form:\n\n"
+ " $( cond; $? cond; $: cond; $) cond; (command form)\n"
+ " cond(, cond?, [cond:, [cond), (operator from)\n\n"
+ " Conditional commands bracket other commands, conditional\n"
+ " operators bracket other numbers and operators in the expression\n"
+ " The conditions (cond) are intrepreted as boolean values, with 0\n"
+ " false and any other value true. Notice that the numbers come off\n"
+ " the number stack so it is not necessary for them to be given with\n"
+ " the specific command or before the specifc operator but it can\n"
+ " be very confusing if this is not done.\n\n"
+ " The commands/operators behave exactly as the following ANSI C\n"
+ " syntax:\n\n"
+ " $( n do if (n) {\n"
+ " $? n if (n) break;\n"
+ " $: n } else if (n) {\n"
+ " $) n } while (n);\n\n"
+ " Thus a simple if/then/else sequence might be:\n\n"
+ " $( condition; $: 1; $) 0\n"
+ " condition( [1: [0)\n\n"
+ " And a simple do while loop:\n\n"
+ " $( 1; $) condition\n"
+ " 1( [condition)\n\n"
+ " Notice that the operator syntax requires [cond: and [cond)";
+ break;
+ CASE('$','('): /* if */
+ p = "conditional: $( condition; do if (condition) {\n";
+ break;
+ CASE('$',':'): /* elif */
+ p = "conditional: $( condition; } else if (condition) {\n";
+ break;
+ CASE('$',')'): /* end+loop if */
+ p = "conditional: $: condition; } while (condition);\n";
+ break;
+ CASE('$','?'): /* break */
+ p = "conditional: $: condition; if (condition) break;\n";
+ break;
+ CASE('e','x'):
+ p = "program termination commands:\n"
+ " !? and !! cause immediate termination of the program.\n"
+ " The currently opened files are closed (and flushed) on\n"
+ " termination and the program exits with the given code.\n"
+ " !? is condition - it only causes an exit if the code is\n"
+ " non zero.";
+ break;
+ CASE('!','?'): /* exit if non-zero */
+ p = "exit: !? code; if (code != 0) exit(code);\n";
+ break;
+ CASE('!','!'): /* exit unconditionally */
+ p = "exit: !! code; exit(code);\n";
+ break;
+ CASE('i','o'):
+ p = "input/output control:\n"
+ " >> << allow files to be opened for write or read (respectively)\n"
+ " A file may be opened for both write and read, but in that case\n"
+ " the first open must be the write one. Such a file has only one\n"
+ " position pointer. Supplying an empty file name to the commands\n"
+ " causes the standard IO stream (stdout or stdin) to be used, but\n"
+ " the file remains open. A file may be reselected by repeating\n"
+ " the open command. The position pointer will not have changed.\n\n"
+ " <> closes a file. If it is the current input or output then the\n"
+ " input or output, as appropriate, is redirected to the standard\n"
+ " streams.\n\n"
+ " <= >= set the input (from) or output (to) pointer. The pointer is\n"
+ " changed on the current input or output device and is a property of\n"
+ " that device, not a global setting.";
+ break;
+ CASE('>','>'): /* write to (no argument reverts to stdout) */
+ p = "io: >> file; select file as the current output device\n"
+ " >> ; select stdout as the current output device\n";
+ break;
+ CASE('<','<'): /* read from */
+ p = "io: << file; select file as the current input device\n"
+ " << ; select stdin as the current input device\n";
+ break;
+ CASE('<','>'): /* close */
+ p = "io: <> file; close file\n";
+ break;
+ CASE('>','<'): /* synonym of close */
+ p = "io: <> file; close file\n";
+ break;
+ CASE('>','='): /* set to pointer */
+ p = "io: >= offset; set the 'to' pointer: output device file pointer\n";
+ break;
+ CASE('<','='): /* set from pointer */
+ p = "io: <= offset; set the 'from' pointer: input device file pointer\n";
+ break;
+ CASE('w','r'):
+ p = "writing to the output:\n"
+ " wb, wl, ws, fb and cp write bytes to the current output device at\n"
+ " the current output position (which may be set using >=.)\n\n"
+ " See the individual command descriptions for more information.";
+ break;
+ CASE('w','b'): /* bigendian number bytes */
+ p = "write: wb number bytes; write number in bytes big endian bytes\n";
+ break;
+ CASE('w','l'): /* little endian number bytes */
+ p = "write: wl number bytes; write number in bytes little endian bytes\n";
+ break;
+ CASE('w','s'): /* write string */
+ p = "write: wl string; write string\n";
+ break;
+ CASE('f','b'): /* fill bytes */
+ p = "write: fb number byte; write number bytes of value 'byte'\n";
+ break;
+ CASE('c','p'): /* copy bytes */
+ p = "write: cp number; copy number bytes from input to output\n";
+ break;
+ CASE('m','e'):
+ p = "writing to stdout:\n"
+ " pr pf and pn allow output to stdout ignoring the current output\n"
+ " device. pf uses a C printf(3) format string and no checking is\n"
+ " made on the validity or number of parameters. The program will\n"
+ " crash if a pointer format (like %s) is used. This is by design.\n"
+ " Use of \\ escapes within the string will probably not produce the\n"
+ " expected result. The only way to output a newline is via the\n"
+ " separate pn command.";
+ break;
+ CASE('p','r'): /* printf("%lu\n") */
+ p = "message: pr number; printf(\"%lu\\n\", number);\n";
+ break;
+ CASE('p','f'): /* printf(string) */
+ p = "message: pf string; printf(string, 1, 2, 3, 4, 5, 6, 7, 8)\n"
+ " uses string as a format string for the\n"
+ " top (up to) 8 arguments on the stack\n"
+ " Empties the stack!\n";
+ break;
+ CASE('p','n'): /* printf("\n") */
+ p = "message: pn; prints a newline (printf(\"\\n\");)\n";
+ break;
+ CASE('.','='):
+ p = ".= [number]\n"
+ " The number is evaluated and pushed to the stack";
+ CASE('a','s'):
+ p = "<C>= [number] (<C> is an upper case character in the range A-Z)\n"
+ " The number is assigned to the variable <C>.";
+ break;
+ CASE('s','t'):
+ p = "string format\n"
+ " A string is either quoted or unquoted. An unquoted string is\n"
+ " the rest of the line, terminated by ';' or newline (or the end\n"
+ " of the command). A quoted string is enclosed in either single\n"
+ " or double quotes (which are removed) and must be the only thing\n"
+ " on the line apart from white space.";
+ break;
+ CASE('n','u'):
+ p = "number format\n"
+ " A number is a post-fix expression consisting of numeric values,\n"
+ " variable values and operators.\n"
+ " A numeric value is anything starting with a digit. 0x prefixes a\n"
+ " hexadecimal value, 0 prefixes an octal value otherwise the value\n"
+ " is interpreted as decimal.\n"
+ " Variables are single upper case characters in the range A-Z,\n"
+ " thus 26 variables are available.\n"
+ " Numeric values and variables are pushed onto a stack which can\n"
+ " store up to 248 numbers.\n"
+ " Operators are single characters not identified as numeric values\n"
+ " or variables. They operate on the stack combining elements.\n"
+ " Use -h operators for more information.";
+ break;
+ CASE('o','p'):
+ p = "operators\n"
+ " The following operators are defined. Operators take one or\n"
+ " two elements from the stack and push back up to two elements\n"
+ " The conditional operators (:?) are special, see the description\n"
+ " under -h conditionals for more information. (Conditional\n"
+ " operators and the conditional commands behave identically.)\n\n"
+ " In the following descriptions 'left' is the last-but-one\n"
+ " number on the stack and 'right' is the last number pushed.\n"
+ " 'new' is a new number pushed on to the top of the stack.\n\n"
+ " arithmetic operators:\n"
+ " *: new := left * right (multiplication)\n"
+ " +: new := left + right\n"
+ " -: new := left - right\n"
+ " /: new := left / right (division)\n"
+ " %: new := left % right (i.e. C style modulus)\n"
+ " <: new := left < right\n"
+ " >: new := left > right\n"
+ " =: new := left == right (i.e. equality)\n"
+ " |: new := left | right (bitwise or)\n"
+ " &: new := left | right (bitwise and)\n"
+ " ^: new := left | right (bitwise xor)\n"
+ " ~: new := ~right (ones complement)\n"
+ " !: new := !right (logical complement - right == 0)\n"
+ " {: new := left << right (bitwise shift left by right bits)\n"
+ " }: new := left << right (bitwise shift right by right bits)\n"
+ " r: new := left ROR right (bitwise rotate right by right bits)\n"
+ " e: new := left SXT right (right least significant bits of\n"
+ " left are sign extended to 32 bits)\n"
+ " m: new := left MASK right (right least significant bits of left\n"
+ " are masked, upper bits become 0)\n"
+ " operators to read bytes:\n"
+ " @: new := input-byte (one byte is read from current input)\n"
+ " b: new := input-big-endian (4 big endian bytes are read)\n"
+ " l: new := input-little-endian (4 little endian bytes)\n"
+ " enquiry operators:\n"
+ " $: the size of the current input device\n"
+ " f: the current 'from' offset\n"
+ " #: the size of the current output device\n"
+ " t: the current 'to' offset\n"
+ " d: the full device number of the current input device\n"
+ " this returns the number of the underlying device for a file\n"
+ " operators to manipulate the stack:\n"
+ " .: new := right,right (i.e. right is duplicated)\n"
+ " p: pop - right is removed from the stack\n"
+ " s: swap - right and left are swapped on the stack\n"
+ " conditional operators:\n"
+ " ( exec := right (execution is stopped if right is 0)\n"
+ " : exec := else if right (execution is resumed or stopped)\n"
+ " ? if right break (break out of if/loop if right)\n"
+ " ) loop if right (end of current if/loop)";
+ break;
+ default:
+ fprintf(stderr, "command '%s' not recognised\n", p);
+ p = 0;
+ }
+
+ if (p != 0)
+ fprintf(stderr, "%s\n", p);
+ }
+ }
+#endif
+ exit(1);
+ } else if (strcmp(argv[1], "-v") == 0)
+ i = 1;
+
+ init_parse(&p, i);
+ ++i;
+ parse(&p, argc-i, argv+i);
+ quit(&p, 0);
+}
git.openpandora.org / openembedded.git / commitdiff