diff --git a/Makefile b/Makefile
index c814f84..57b4258 100644
--- a/Makefile
+++ b/Makefile
@@ -25,7 +25,7 @@ clean:
 
 .SUFFIXES: .c .o
 
-mspdebug: main.o fet.o rf2500.o dis.o uif.o
+mspdebug: main.o fet.o rf2500.o dis.o uif.o ihex.o elf32.o
 	$(CC) $(CFLAGS) -o $@ $^ -lusb
 
 .c.o:
diff --git a/binfile.h b/binfile.h
new file mode 100644
index 0000000..bccc442
--- /dev/null
+++ b/binfile.h
@@ -0,0 +1,36 @@
+/* MSPDebug - debugging tool for the eZ430
+ * Copyright (C) 2009 Daniel Beer
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef BINFILE_H_
+#define BINFILE_H_
+
+#include <stdio.h>
+#include <sys/types.h>
+
+/* Callback for binary image data */
+typedef int (*imgfunc_t)(u_int16_t addr, const u_int8_t *data, int len);
+
+/* Intel HEX file support */
+int ihex_check(FILE *in);
+int ihex_extract(FILE *in, imgfunc_t cb);
+
+/* ELF32 file support */
+int elf32_check(FILE *in);
+int elf32_extract(FILE *in, imgfunc_t cb);
+
+#endif
diff --git a/elf32.c b/elf32.c
new file mode 100644
index 0000000..fb9c51a
--- /dev/null
+++ b/elf32.c
@@ -0,0 +1,192 @@
+/* MSPDebug - debugging tool for the eZ430
+ * Copyright (C) 2009 Daniel Beer
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <elf.h>
+#include "binfile.h"
+
+#define EM_MSP430	0x69
+
+static const u_int8_t elf32_id[] = {
+	ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, ELFCLASS32
+};
+
+#define MAX_PHDRS	32
+#define MAX_SHDRS	32
+
+static Elf32_Ehdr file_ehdr;
+static Elf32_Phdr file_phdrs[MAX_PHDRS];
+static Elf32_Shdr file_shdrs[MAX_SHDRS];
+
+static int read_ehdr(FILE *in)
+{
+	int i;
+
+	/* Read and check the ELF header */
+	rewind(in);
+	if (fread(&file_ehdr, sizeof(file_ehdr), 1, in) < 0) {
+		perror("elf32: couldn't read ELF header");
+		return -1;
+	}
+
+	for (i = 0; i < sizeof(elf32_id); i++)
+		if (file_ehdr.e_ident[i] != elf32_id[i]) {
+			fprintf(stderr, "elf32: not an ELF32 file\n");
+			return -1;
+		}
+
+	return 0;
+}
+
+static int read_phdr(FILE *in)
+{
+	int i;
+
+	if (file_ehdr.e_phnum > MAX_PHDRS) {
+		fprintf(stderr, "elf32: too many program headers: %d\n",
+			file_ehdr.e_phnum);
+		return -1;
+	}
+
+	for (i = 0; i < file_ehdr.e_phnum; i++) {
+		if (fseek(in, i * file_ehdr.e_phentsize + file_ehdr.e_phoff,
+			  SEEK_SET) < 0) {
+			fprintf(stderr, "elf32: can't seek to phdr %d\n", i);
+			return -1;
+		}
+
+		if (fread(&file_phdrs[i], sizeof(file_phdrs[0]), 1, in) < 0) {
+			fprintf(stderr, "elf32: can't read phdr %d: %s\n",
+				i, strerror(errno));
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int read_shdr(FILE *in)
+{
+	int i;
+
+	if (file_ehdr.e_shnum > MAX_SHDRS) {
+		fprintf(stderr, "elf32: too many section headers: %d\n",
+			file_ehdr.e_shnum);
+		return -1;
+	}
+
+	for (i = 0; i < file_ehdr.e_shnum; i++) {
+		if (fseek(in, i * file_ehdr.e_shentsize + file_ehdr.e_shoff,
+			  SEEK_SET) < 0) {
+			fprintf(stderr, "elf32: can't seek to phdr %d\n", i);
+			return -1;
+		}
+
+		if (fread(&file_shdrs[i], sizeof(file_shdrs[0]), 1, in) < 0) {
+			fprintf(stderr, "elf32: can't read phdr %d: %s\n",
+				i, strerror(errno));
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static u_int32_t file_to_phys(u_int32_t v)
+{
+	int i;
+
+	for (i = 0; i < file_ehdr.e_phnum; i++) {
+		Elf32_Phdr *p = &file_phdrs[i];
+
+		if (v >= p->p_offset && v - p->p_offset < p->p_filesz)
+			return v - p->p_offset + p->p_paddr;
+	}
+
+	return v;
+}
+
+static int feed_section(FILE *in, int offset, int size, imgfunc_t cb)
+{
+	u_int8_t buf[1024];
+	u_int16_t addr = file_to_phys(offset);
+
+	if (fseek(in, offset, SEEK_SET) < 0) {
+		perror("elf32: can't seek to section");
+		return -1;
+	}
+
+	while (size) {
+		int ask = size > sizeof(buf) ? sizeof(buf) : size;
+		int len = fread(buf, 1, ask, in);
+
+		if (len < 0) {
+			perror("elf32: can't read section");
+			return -1;
+		}
+
+		if (cb(addr, buf, len) < 0)
+			return -1;
+
+		size -= len;
+		offset += len;
+		addr += len;
+	}
+
+	return 0;
+}
+
+int elf32_extract(FILE *in, imgfunc_t cb)
+{
+	int i;
+
+	if (read_ehdr(in) < 0)
+		return -1;
+	if (file_ehdr.e_machine != EM_MSP430) {
+		fprintf(stderr, "elf32: this is not an MSP430 ELF32\n");
+		return -1;
+	}
+
+	if (read_phdr(in) < 0)
+		return -1;
+	if (read_shdr(in) < 0)
+		return -1;
+
+	for (i = 0; i < file_ehdr.e_shnum; i++) {
+		Elf32_Shdr *s = &file_shdrs[i];
+
+		if (s->sh_type == SHT_PROGBITS && s->sh_flags & SHF_ALLOC &&
+			feed_section(in, s->sh_offset, s->sh_size, cb) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+int elf32_check(FILE *in)
+{
+	int i;
+
+	rewind(in);
+	for (i = 0; i < sizeof(elf32_id); i++)
+		if (fgetc(in) != elf32_id[i])
+			return 0;
+
+	return 1;
+}
diff --git a/fet.c b/fet.c
index a76773a..504ab63 100644
--- a/fet.c
+++ b/fet.c
@@ -105,7 +105,7 @@ static void init_codes(void)
  * needs to be stored in little-endian format at the end of the payload.
  */
 
-static u_int16_t calc_checksum(const char *data, int len)
+static u_int16_t calc_checksum(const u_int8_t *data, int len)
 {
 	int i;
 	u_int16_t cksum = 0xffff;
@@ -140,13 +140,13 @@ static u_int16_t calc_checksum(const char *data, int len)
  *
  * No checksums are included.
  */
-static int send_rf2500_data(const char *data, int len)
+static int send_rf2500_data(const u_int8_t *data, int len)
 {
 	int offset = 0;
 
 	assert (fet_transport != NULL);
 	while (len) {
-		char pbuf[63];
+		u_int8_t pbuf[63];
 		int plen = len > 59 ? 59 : len;
 
 		pbuf[0] = 0x83;
@@ -165,7 +165,7 @@ static int send_rf2500_data(const char *data, int len)
 	return 0;
 }
 
-static char fet_buf[65538];
+static u_int8_t fet_buf[65538];
 static int fet_len;
 
 #define MAX_PARAMS		16
@@ -178,7 +178,7 @@ static struct {
 	int		argc;
 	u_int32_t	argv[MAX_PARAMS];
 
-	char		*data;
+	u_int8_t	*data;
 	int		datalen;
 } fet_reply;
 
@@ -372,12 +372,12 @@ static int recv_packet(void)
 
 static int send_command(int command_code,
 		        const u_int32_t *params, int nparams,
-			const char *extra, int exlen)
+			const u_int8_t *extra, int exlen)
 {
-	char datapkt[256];
+	u_int8_t datapkt[256];
 	int len = 0;
 
-	char buf[512];
+	u_int8_t buf[512];
 	u_int16_t cksum;
 	int i = 0;
 	int j;
@@ -449,7 +449,7 @@ static int send_command(int command_code,
 	return fet_transport->send(buf, i);
 }
 
-static int xfer(int command_code, const char *data, int datalen,
+static int xfer(int command_code, const u_int8_t *data, int datalen,
 		int nparams, ...)
 {
 	u_int32_t params[MAX_PARAMS];
@@ -534,7 +534,7 @@ static const struct {
 	}
 };
 
-extern void hexdump(int addr, const char *data, int len);
+extern void hexdump(int addr, const u_int8_t *data, int len);
 
 static int do_identify(void)
 {
@@ -633,7 +633,7 @@ int fet_open(const struct fet_transport *tr, int proto_flags, int vcc_mv)
 	 * This is RF2500-specific.
 	 */
 	if (fet_is_rf2500) {
-		static const char data[] = {
+		static const u_int8_t data[] = {
 			0x00, 0x80, 0xff, 0xff, 0x00, 0x00, 0x00, 0x10,
 			0xff, 0x10, 0x40, 0x00, 0x00, 0x02, 0xff, 0x05,
 			0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01, 0x00,
@@ -703,7 +703,7 @@ int fet_get_context(u_int16_t *regs)
 
 int fet_set_context(u_int16_t *regs)
 {
-	char buf[FET_NUM_REGS * 4];
+	u_int8_t buf[FET_NUM_REGS * 4];;
 	int i;
 	int ret;
 
@@ -729,7 +729,7 @@ int fet_set_context(u_int16_t *regs)
 	return 0;
 }
 
-int fet_read_mem(u_int16_t addr, char *buffer, int count)
+int fet_read_mem(u_int16_t addr, u_int8_t *buffer, int count)
 {
 	while (count) {
 		int plen = count > 128 ? 128 : count;
@@ -755,7 +755,7 @@ int fet_read_mem(u_int16_t addr, char *buffer, int count)
 	return 0;
 }
 
-int fet_write_mem(u_int16_t addr, char *buffer, int count)
+int fet_write_mem(u_int16_t addr, const u_int8_t *buffer, int count)
 {
 	while (count) {
 		int plen = count > 128 ? 128 : count;
diff --git a/fet.h b/fet.h
index 2307c83..3470885 100644
--- a/fet.h
+++ b/fet.h
@@ -39,8 +39,8 @@ int rf2500_open(void);
  * high-level functions.
  */
 struct fet_transport {
-	int (*send)(const char *data, int len);
-	int (*recv)(char *data, int max_len);
+	int (*send)(const u_int8_t *data, int len);
+	int (*recv)(u_int8_t *data, int max_len);
 	void (*close)(void);
 };
 
@@ -90,8 +90,8 @@ int fet_erase(int type, u_int16_t addr, int len);
 /* Read and write memory. fet_write_mem can be used to reflash the
  * device, but only after an erase.
  */
-int fet_read_mem(u_int16_t addr, char *buffer, int count);
-int fet_write_mem(u_int16_t addr, char *buffer, int count);
+int fet_read_mem(u_int16_t addr, u_int8_t *buffer, int count);
+int fet_write_mem(u_int16_t addr, const u_int8_t *buffer, int count);
 
 /* Fetch the device status. If the device is currently running, then
  * the FET_POLL_RUNNING flag will be set. FET_POLL_BREAKPOINT is set
diff --git a/ihex.c b/ihex.c
new file mode 100644
index 0000000..e7d7d07
--- /dev/null
+++ b/ihex.c
@@ -0,0 +1,93 @@
+/* MSPDebug - debugging tool for the eZ430
+ * Copyright (C) 2009 Daniel Beer
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include "binfile.h"
+
+int ihex_check(FILE *in)
+{
+	rewind(in);
+	return fgetc(in) == ':';
+}
+
+static int feed_line(FILE *in, u_int8_t *data, int nbytes, imgfunc_t cb)
+{
+	u_int8_t cksum = 0;
+	int i;
+
+	if (nbytes < 5 || data[3])
+		return 0;
+
+	/* Verify checksum */
+	for (i = 0; i + 1 < nbytes; i++)
+		cksum += data[i];
+	cksum = ~(cksum - 1) & 0xff;
+
+	if (data[nbytes - 1] != cksum) {
+		fprintf(stderr, "ihex: invalid checksum: %02x "
+			"(calculated %02x)\n", data[nbytes - 1], cksum);
+		return -1;
+	}
+
+	return cb(((u_int16_t)data[1]) << 8 | ((u_int16_t)data[2]),
+		  data + 4, nbytes - 5);
+}
+
+int ihex_extract(FILE *in, imgfunc_t cb)
+{
+	char buf[128];
+	int lno = 0;
+
+	rewind(in);
+	while (fgets(buf, sizeof(buf), in)) {
+		int len = strlen(buf);
+		int i;
+		u_int8_t data[64];
+		int nbytes;
+
+		lno++;
+		if (buf[0] != ':') {
+			fprintf(stderr, "ihex: line %d: invalid start "
+				"marker\n", lno);
+			continue;
+		}
+
+		/* Trim trailing whitespace */
+		while (len && isspace(buf[len - 1]))
+			len--;
+		buf[len] = 0;
+
+		/* Decode hex digits */
+		nbytes = (len - 1) / 2;
+		for (i = 0; i < nbytes; i++) {
+			char d[] = {buf[i * 2 + 1], buf[i * 2 + 2], 0};
+
+			data[i] = strtoul(d, NULL, 16);
+		}
+
+		/* Handle the line */
+		if (feed_line(in, data, nbytes, cb) < 0) {
+			fprintf(stderr, "ihex: error on line %d\n", lno);
+			return -1;
+		}
+	}
+
+	return 0;
+}
diff --git a/main.c b/main.c
index ccc8b14..a58aa1e 100644
--- a/main.c
+++ b/main.c
@@ -26,8 +26,9 @@
 
 #include "dis.h"
 #include "fet.h"
+#include "binfile.h"
 
-void hexdump(int addr, const char *data, int len)
+void hexdump(int addr, const u_int8_t *data, int len)
 {
 	int offset = 0;
 
@@ -145,7 +146,7 @@ static int cmd_md(char **arg)
 	}
 
 	while (length) {
-		char buf[128];
+		u_int8_t buf[128];
 		int blen = length > sizeof(buf) ? sizeof(buf) : length;
 
 		if (fet_read_mem(offset, buf, blen) < 0)
@@ -202,7 +203,7 @@ static int cmd_dis(char **arg)
 	char *len_text = get_arg(arg);
 	unsigned int offset = 0;
 	unsigned int length = 0;
-	char buf[128];
+	u_int8_t buf[128];
 
 	if (!off_text) {
 		fprintf(stderr, "md: offset must be specified\n");
@@ -235,7 +236,7 @@ static int cmd_reset(char **arg)
 static int cmd_regs(char **arg)
 {
 	u_int16_t regs[FET_NUM_REGS];
-	char code[16];
+	u_int8_t code[16];
 
 	if (fet_get_context(regs) < 0)
 		return -1;
@@ -325,107 +326,76 @@ static int cmd_step(char **arg)
 	return cmd_regs(NULL);
 }
 
-static int hexval(const char *text, int len)
-{
-	int value = 0;
+/************************************************************************
+ * Flash image programming state machine.
+ */
 
-	while (len && *text) {
-		value <<= 4;
-
-		if (*text >= 'A' && *text <= 'F')
-			value += *text - 'A' + 10;
-		else if (*text >= 'a' && *text <= 'f')
-			value += *text - 'a' + 10;
-		else if (isdigit(*text))
-			value += *text - '0';
-
-		text++;
-		len--;
-	}
-
-	return value;
-}
-
-static char prog_buf[128];
+static u_int8_t prog_buf[128];
 static u_int16_t prog_addr;
 static int prog_len;
+static int prog_have_erased;
+
+static void prog_init(void)
+{
+	prog_len = 0;
+	prog_have_erased = 0;
+}
 
 static int prog_flush(void)
 {
-	int wlen = prog_len;
+	while (prog_len) {
+		int wlen = prog_len;
 
-	if (!prog_len)
-		return 0;
+		/* Writing across this address seems to cause a hang */
+		if (prog_addr < 0x999a && wlen + prog_addr > 0x999a)
+			wlen = 0x999a - prog_addr;
 
-	/* Writing across this address seems to cause a hang */
-	if (prog_addr < 0x999a && wlen + prog_addr > 0x999a)
-		wlen = 0x999a - prog_addr;
+		if (!prog_have_erased) {
+			printf("Erasing...\n");
+			if (fet_erase(FET_ERASE_ALL, 0x1000, 0x100) < 0)
+				return -1;
+			prog_have_erased = 1;
+		}
 
-	printf("Writing %3d bytes to %04x...\n", wlen, prog_addr);
+		printf("Writing %3d bytes to %04x...\n", wlen, prog_addr);
+		if (fet_write_mem(prog_addr, prog_buf, wlen) < 0)
+		        return -1;
 
-	if (fet_write_mem(prog_addr, prog_buf, wlen) < 0)
-		return -1;
-
-	memmove(prog_buf, prog_buf + wlen, prog_len - wlen);
-	prog_len -= wlen;
-	prog_addr += wlen;
-
-	return 0;
-}
-
-static int prog_hex(int lno, const char *hex)
-{
-	int len = strlen(hex);
-	int count, address, type, cksum = 0;
-	int i;
-
-	if (*hex != ':')
-		return 0;
-
-	hex++;
-	len--;
-
-	while (len && isspace(hex[len - 1]))
-		len--;
-
-	if (len < 10)
-		return 0;
-
-	count = hexval(hex, 2);
-	address = hexval(hex + 2, 4);
-	type = hexval(hex + 6, 2);
-
-	if (type)
-		return 0;
-
-	for (i = 0; i + 2 < len; i += 2)
-		cksum = (cksum + hexval(hex + i, 2))
-			& 0xff;
-	cksum = ~(cksum - 1) & 0xff;
-
-	if (count * 2 + 10 != len) {
-		fprintf(stderr, "warning: length mismatch at line %d\n", lno);
-		count = (len - 10) / 2;
+		memmove(prog_buf, prog_buf + wlen, prog_len - wlen);
+		prog_len -= wlen;
+		prog_addr += wlen;
 	}
 
-	if (cksum != hexval(hex + len - 2, 2))
-		fprintf(stderr, "warning: invalid checksum at line %d\n", lno);
+        return 0;
+}
 
-	for (i = 0; i < count; i++) {
-		int offset;
+static int prog_feed(u_int16_t addr, const u_int8_t *data, int len)
+{
+	/* Flush if this section is discontiguous */
+	if (prog_len && prog_addr + prog_len != addr && prog_flush() < 0)
+		return -1;
 
-		offset = address + i - prog_addr;
-		if (offset < 0 || offset >= sizeof(prog_buf))
+	if (!prog_len)
+		prog_addr = addr;
+
+	/* Add the buffer in piece by piece, flushing when it gets
+	 * full.
+	 */
+	while (len) {
+		int count = sizeof(prog_buf) - prog_len;
+
+		if (count > len)
+			count = len;
+
+		if (!count) {
 			if (prog_flush() < 0)
 				return -1;
-
-		if (!prog_len)
-			prog_addr = address + i;
-
-		offset = address + i - prog_addr;
-		prog_buf[offset] = hexval(hex + 8 + i * 2, 2);
-		if (offset + 1 > prog_len)
-			prog_len = offset + 1;
+		} else {
+			memcpy(prog_buf + prog_len, data, count);
+			prog_len += count;
+			data += count;
+			len -= count;
+		}
 	}
 
 	return 0;
@@ -434,35 +404,31 @@ static int prog_hex(int lno, const char *hex)
 static int cmd_prog(char **arg)
 {
 	FILE *in = fopen(*arg, "r");
-	char text[256];
-	int lno = 1;
+	int result = 0;
 
 	if (!in) {
 		fprintf(stderr, "prog: %s: %s\n", *arg, strerror(errno));
 		return -1;
 	}
 
-	printf("Erasing...\n");
-	if (fet_erase(FET_ERASE_ALL, 0x1000, 0x100) < 0) {
+	if (fet_reset(FET_RESET_ALL | FET_RESET_HALT) < 0) {
 		fclose(in);
 		return -1;
 	}
 
-	if (fet_reset(FET_RESET_ALL | FET_RESET_HALT) < 0)
-		return -1;
+	prog_init();
+	if (elf32_check(in))
+		result = elf32_extract(in, prog_feed);
+	else if (ihex_check(in))
+		result = ihex_extract(in, prog_feed);
+	else
+		fprintf(stderr, "%s: unknown file type\n", *arg);
+
+	if (!result)
+		result = prog_flush();
 
-	prog_len = 0;
-	while (fgets(text, sizeof(text), in))
-		if (prog_hex(lno++, text) < 0) {
-			fclose(in);
-			return -1;
-		}
 	fclose(in);
-
-	if (prog_flush() < 0)
-		return -1;
-
-	return fet_reset(FET_RESET_ALL | FET_RESET_HALT);
+	return result;
 }
 
 static const struct command all_commands[] = {
diff --git a/rf2500.c b/rf2500.c
index d5934a7..6e2ccc7 100644
--- a/rf2500.c
+++ b/rf2500.c
@@ -22,7 +22,7 @@
 
 #include "fet.h"
 
-void hexdump(int addr, const char *data, int len);
+extern void hexdump(int addr, const u_int8_t *data, int len);
 
 /*********************************************************************
  * USB transport
@@ -87,10 +87,10 @@ static int usbtr_open_device(struct usb_device *dev)
 	return -1;
 }
 
-static int usbtr_send(const char *data, int len)
+static int usbtr_send(const u_int8_t *data, int len)
 {
 	while (len) {
-		char pbuf[256];
+		u_int8_t pbuf[256];
 		int plen = len > 255 ? 255 : len;
 		int txlen = plen + 1;
 
@@ -112,7 +112,7 @@ static int usbtr_send(const char *data, int len)
 		hexdump(0, pbuf, txlen);
 #endif
 		if (usb_bulk_write(usbtr_handle, USB_FET_OUT_EP,
-			pbuf, txlen, 10000) < 0) {
+			(const char *)pbuf, txlen, 10000) < 0) {
 			perror("usbtr_send");
 			return -1;
 		}
@@ -124,7 +124,7 @@ static int usbtr_send(const char *data, int len)
 	return 0;
 }
 
-static char usbtr_buf[64];
+static u_int8_t usbtr_buf[64];
 static int usbtr_len;
 static int usbtr_offset;
 
@@ -136,13 +136,14 @@ static void usbtr_flush(void)
 			buf, sizeof(buf), 100) >= 0);
 }
 
-static int usbtr_recv(char *databuf, int max_len)
+static int usbtr_recv(u_int8_t *databuf, int max_len)
 {
 	int rlen;
 
 	if (usbtr_offset >= usbtr_len) {
 		if (usb_bulk_read(usbtr_handle, USB_FET_IN_EP,
-				usbtr_buf, sizeof(usbtr_buf), 10000) < 0) {
+				(char *)usbtr_buf, sizeof(usbtr_buf),
+				10000) < 0) {
 			perror("usbtr_recv");
 			return -1;
 		}
diff --git a/uif.c b/uif.c
index d871e64..222f327 100644
--- a/uif.c
+++ b/uif.c
@@ -28,11 +28,11 @@
 
 #include "fet.h"
 
-void hexdump(int addr, const char *data, int len);
+extern void hexdump(int addr, const u_int8_t *data, int len);
 
 static int serial_fd = -1;
 
-static int serial_send(const char *data, int len)
+static int serial_send(const u_int8_t *data, int len)
 {
 	int result;
 
@@ -60,7 +60,7 @@ static int serial_send(const char *data, int len)
 	return 0;
 }
 
-static int serial_recv(char *data, int max_len)
+static int serial_recv(u_int8_t *data, int max_len)
 {
 	int len;