Move devio to a separate package

BKrev: 42a62066p_4MA9b5mKFPNSB_JVH1YA

4 files changed, 4 insertions, 1772 deletions

diff --git a/packages/devio/devio-native_cvs.bb b/packages/devio/devio-native_cvs.bb
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/packages/devio/devio-native_cvs.bb
diff --git a/packages/devio/devio_cvs.bb b/packages/devio/devio_cvs.bb
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/packages/devio/devio_cvs.bb
diff --git a/packages/openslug-init/openslug-init-0.10/devio.c b/packages/openslug-init/openslug-init-0.10/devio.c
deleted file mode 100644
index bfaace2da1..0000000000
--- a/packages/openslug-init/openslug-init-0.10/devio.c
+++ /dev/null
@@ -1,1767 +0,0 @@
-/* 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(