diff --git a/src/flash/ecos.c b/src/flash/ecos.c
index c12ed9d24..b2ffadffa 100644
--- a/src/flash/ecos.c
+++ b/src/flash/ecos.c
@@ -152,8 +152,8 @@ FLASH_BANK_COMMAND_HANDLER(ecosflash_flash_bank_command)
 
 static int loadDriver(struct ecosflash_flash_bank *info)
 {
-	uint32_t buf_cnt;
-	uint32_t image_size;
+	size_t buf_cnt;
+	size_t image_size;
 	struct image image;
 
 	image.base_address_set = 0;
@@ -182,7 +182,8 @@ static int loadDriver(struct ecosflash_flash_bank *info)
 		}
 		target_write_buffer(target, image.sections[i].base_address, buf_cnt, buffer);
 		image_size += buf_cnt;
-		LOG_DEBUG("%" PRIu32 " byte written at address 0x%8.8" PRIx32 "", buf_cnt, image.sections[i].base_address);
+		LOG_DEBUG("%zu bytes written at address 0x%8.8" PRIx32 "",
+				buf_cnt, image.sections[i].base_address);
 
 		free(buffer);
 	}
diff --git a/src/flash/flash.c b/src/flash/flash.c
index 03d4547d4..adc141195 100644
--- a/src/flash/flash.c
+++ b/src/flash/flash.c
@@ -811,7 +811,6 @@ COMMAND_HANDLER(handle_flash_write_bank_command)
 {
 	uint32_t offset;
 	uint8_t *buffer;
-	uint32_t buf_cnt;
 	struct fileio fileio;
 
 	if (argc != 3)
@@ -833,6 +832,7 @@ COMMAND_HANDLER(handle_flash_write_bank_command)
 	}
 
 	buffer = malloc(fileio.size);
+	size_t buf_cnt;
 	if (fileio_read(&fileio, fileio.size, buffer, &buf_cnt) != ERROR_OK)
 	{
 		free(buffer);
@@ -1059,7 +1059,7 @@ static int flash_write_unlock(struct target *target, struct image *image, uint32
 		/* read sections to the buffer */
 		while (buffer_size < run_size)
 		{
-			uint32_t size_read;
+			size_t size_read;
 
 			size_read = run_size - buffer_size;
 			if (size_read > image->sections[section].size - section_offset)
diff --git a/src/flash/lpc2900.c b/src/flash/lpc2900.c
index b80079df0..dc916689d 100644
--- a/src/flash/lpc2900.c
+++ b/src/flash/lpc2900.c
@@ -631,7 +631,7 @@ COMMAND_HANDLER(lpc2900_handle_read_custom_command)
 		return ret;
 	}
 
-	uint32_t nwritten;
+	size_t nwritten;
 	ret = fileio_write( &fileio, sizeof(customer),
                         (const uint8_t *)customer, &nwritten );
 	if( ret != ERROR_OK )
@@ -755,7 +755,7 @@ COMMAND_HANDLER(lpc2900_handle_write_custom_command)
 	/* Page 4 */
 	uint32_t offset = ISS_CUSTOMER_START1 % FLASH_PAGE_SIZE;
 	memset( page, 0xff, FLASH_PAGE_SIZE );
-	uint32_t size_read;
+	size_t size_read;
 	retval = image_read_section( &image, 0, 0,
 	                             ISS_CUSTOMER_SIZE1, &page[offset], &size_read);
 	if( retval != ERROR_OK )
diff --git a/src/flash/mflash.c b/src/flash/mflash.c
index 4356f2709..062064275 100644
--- a/src/flash/mflash.c
+++ b/src/flash/mflash.c
@@ -705,7 +705,7 @@ static int mg_mflash_write(uint32_t addr, uint8_t *buff, uint32_t len)
 
 COMMAND_HANDLER(mg_write_cmd)
 {
-	uint32_t address, buf_cnt, cnt, res, i;
+	uint32_t address, cnt, res, i;
 	uint8_t *buffer;
 	struct fileio fileio;
 	int ret;
@@ -732,6 +732,7 @@ COMMAND_HANDLER(mg_write_cmd)
 	struct duration bench;
 	duration_start(&bench);
 
+	size_t buf_cnt;
 	for (i = 0; i < cnt; i++) {
 		if ((ret = fileio_read(&fileio, MG_FILEIO_CHUNK, buffer, &buf_cnt)) !=
 				ERROR_OK)
@@ -769,7 +770,7 @@ mg_write_cmd_err:
 
 COMMAND_HANDLER(mg_dump_cmd)
 {
-	uint32_t address, size_written, size, cnt, res, i;
+	uint32_t address, size, cnt, res, i;
 	uint8_t *buffer;
 	struct fileio fileio;
 	int ret;
@@ -797,6 +798,7 @@ COMMAND_HANDLER(mg_dump_cmd)
 	struct duration bench;
 	duration_start(&bench);
 
+	size_t size_written;
 	for (i = 0; i < cnt; i++) {
 		if ((ret = mg_mflash_read(address, buffer, MG_FILEIO_CHUNK)) != ERROR_OK)
 			goto mg_dump_cmd_err;
diff --git a/src/flash/nand.c b/src/flash/nand.c
index 9d997fadd..71a67c45b 100644
--- a/src/flash/nand.c
+++ b/src/flash/nand.c
@@ -1453,8 +1453,8 @@ static COMMAND_HELPER(nand_fileio_parse_args, struct nand_fileio_state *state,
 static int nand_fileio_read(struct nand_device *nand,
 		struct nand_fileio_state *s)
 {
-	uint32_t total_read = 0;
-	uint32_t one_read;
+	size_t total_read = 0;
+	size_t one_read;
 
 	if (NULL != s->page)
 	{
@@ -1616,7 +1616,7 @@ COMMAND_HANDLER(handle_nand_dump_command)
 
 	while (s.size > 0)
 	{
-		uint32_t size_written;
+		size_t size_written;
 		int retval = nand_read_page(nand, s.address / nand->page_size,
 				s.page, s.page_size, s.oob, s.oob_size);
 		if (ERROR_OK != retval)
diff --git a/src/helper/fileio.c b/src/helper/fileio.c
index 84d46bd57..8f2ce2204 100644
--- a/src/helper/fileio.c
+++ b/src/helper/fileio.c
@@ -143,7 +143,7 @@ int fileio_close(struct fileio *fileio)
 	return retval;
 }
 
-int fileio_seek(struct fileio *fileio, uint32_t position)
+int fileio_seek(struct fileio *fileio, size_t position)
 {
 	int retval;
 	if ((retval = fseek(fileio->file, position, SEEK_SET)) != 0)
@@ -155,14 +155,16 @@ int fileio_seek(struct fileio *fileio, uint32_t position)
 	return ERROR_OK;
 }
 
-static inline int fileio_local_read(struct fileio *fileio, uint32_t size, uint8_t *buffer, uint32_t *size_read)
+static int fileio_local_read(struct fileio *fileio,
+		size_t size, void *buffer, size_t *size_read)
 {
-	*size_read = fread(buffer, 1, size, fileio->file);
-
-	return ERROR_OK;
+	ssize_t retval = fread(buffer, 1, size, fileio->file);
+	*size_read = (retval >= 0) ? retval : 0;
+	return (retval < 0) ? retval : ERROR_OK;
 }
 
-int fileio_read(struct fileio *fileio, uint32_t size, uint8_t *buffer, uint32_t *size_read)
+int fileio_read(struct fileio *fileio, size_t size, void *buffer,
+		size_t *size_read)
 {
 	return fileio_local_read(fileio, size, buffer, size_read);
 }
@@ -170,17 +172,17 @@ int fileio_read(struct fileio *fileio, uint32_t size, uint8_t *buffer, uint32_t
 int fileio_read_u32(struct fileio *fileio, uint32_t *data)
 {
 	uint8_t buf[4];
-	uint32_t size_read;
-	int retval;
-
-	if ((retval = fileio_local_read(fileio, 4, buf, &size_read)) != ERROR_OK)
-		return retval;
-	*data = be_to_h_u32(buf);
-
-	return ERROR_OK;
+	size_t size_read;
+	int retval = fileio_local_read(fileio, sizeof(uint32_t), buf, &size_read);
+	if (ERROR_OK == retval && sizeof(uint32_t) != size_read)
+		retval = -EIO;
+	if (ERROR_OK == retval)
+		*data = be_to_h_u32(buf);
+	return retval;
 }
 
-static inline int fileio_local_fgets(struct fileio *fileio, uint32_t size, char *buffer)
+static int fileio_local_fgets(struct fileio *fileio,
+		size_t size, void *buffer)
 {
 	if (fgets(buffer, size, fileio->file) == NULL)
 		return ERROR_FILEIO_OPERATION_FAILED;
@@ -188,40 +190,37 @@ static inline int fileio_local_fgets(struct fileio *fileio, uint32_t size, char
 	return ERROR_OK;
 }
 
-int fileio_fgets(struct fileio *fileio, uint32_t size, char *buffer)
+int fileio_fgets(struct fileio *fileio, size_t size, void *buffer)
 {
 	return fileio_local_fgets(fileio, size, buffer);
 }
 
-static inline int fileio_local_write(struct fileio *fileio, uint32_t size, const uint8_t *buffer, uint32_t *size_written)
+static int fileio_local_write(struct fileio *fileio,
+		size_t size, const void *buffer, size_t *size_written)
 {
-	*size_written = fwrite(buffer, 1, size, fileio->file);
-
-	return ERROR_OK;
+	ssize_t retval = fwrite(buffer, 1, size, fileio->file);
+	*size_written = (retval >= 0) ? retval : 0;
+	return (retval < 0) ? retval : ERROR_OK;
 }
 
-int fileio_write(struct fileio *fileio, uint32_t size, const uint8_t *buffer, uint32_t *size_written)
+int fileio_write(struct fileio *fileio,
+		size_t size, const void *buffer, size_t *size_written)
 {
-	int retval;
-
-	retval = fileio_local_write(fileio, size, buffer, size_written);
-
+	int retval = fileio_local_write(fileio, size, buffer, size_written);
 	if (retval == ERROR_OK)
 		fileio->size += *size_written;
-
-	return retval;;
+	return retval;
 }
 
 int fileio_write_u32(struct fileio *fileio, uint32_t data)
 {
 	uint8_t buf[4];
-	uint32_t size_written;
-	int retval;
-
 	h_u32_to_be(buf, data);
 
-	if ((retval = fileio_local_write(fileio, 4, buf, &size_written)) != ERROR_OK)
-		return retval;
+	size_t size_written;
+	int retval = fileio_write(fileio, 4, buf, &size_written);
+	if (ERROR_OK == retval && size_written != sizeof(uint32_t))
+		retval = -EIO;
 
-	return ERROR_OK;
+	return retval;
 }
diff --git a/src/helper/fileio.h b/src/helper/fileio.h
index 6ed6fe454..325b441ff 100644
--- a/src/helper/fileio.h
+++ b/src/helper/fileio.h
@@ -58,13 +58,13 @@ int fileio_open(struct fileio *fileio,
 	const char *url, enum fileio_access access, enum fileio_type type);
 int fileio_close(struct fileio *fileio);
 
-int fileio_seek(struct fileio *fileio, uint32_t position);
-int fileio_fgets(struct fileio *fileio, uint32_t size, char *buffer);
+int fileio_seek(struct fileio *fileio, size_t position);
+int fileio_fgets(struct fileio *fileio, size_t size, void *buffer);
 
 int fileio_read(struct fileio *fileio,
-		uint32_t size, uint8_t *buffer, uint32_t *size_read);
+		size_t size, void *buffer, size_t *size_read);
 int fileio_write(struct fileio *fileio,
-		uint32_t size, const uint8_t *buffer, uint32_t *size_written);
+		size_t size, const void *buffer, size_t *size_written);
 
 int fileio_read_u32(struct fileio *fileio, uint32_t *data);
 int fileio_write_u32(struct fileio *fileio, uint32_t data);
diff --git a/src/target/etm.c b/src/target/etm.c
index 5a0ffed55..fa7a71b2c 100644
--- a/src/target/etm.c
+++ b/src/target/etm.c
@@ -640,7 +640,7 @@ static int etm_read_instruction(struct etm_context *ctx, struct arm_instruction
 {
 	int i;
 	int section = -1;
-	uint32_t size_read;
+	size_t size_read;
 	uint32_t opcode;
 	int retval;
 
diff --git a/src/target/image.c b/src/target/image.c
index bba4675ff..8774c2517 100644
--- a/src/target/image.c
+++ b/src/target/image.c
@@ -48,7 +48,7 @@ static int autodetect_image_type(struct image *image, const char *url)
 {
 	int retval;
 	struct fileio fileio;
-	uint32_t read_bytes;
+	size_t read_bytes;
 	uint8_t buffer[9];
 
 	/* read the first 4 bytes of image */
@@ -175,7 +175,7 @@ static int image_ihex_buffer_complete(struct image *image)
 		uint32_t record_type;
 		uint32_t checksum;
 		uint8_t cal_checksum = 0;
-		uint32_t bytes_read = 0;
+		size_t bytes_read = 0;
 
 		if (sscanf(&lpszLine[bytes_read], ":%2" SCNx32 "%4" SCNx32 "%2" SCNx32 , &count, &address, &record_type) != 3)
 		{
@@ -360,7 +360,7 @@ static int image_ihex_buffer_complete(struct image *image)
 static int image_elf_read_headers(struct image *image)
 {
 	struct image_elf *elf = image->type_private;
-	uint32_t read_bytes;
+	size_t read_bytes;
 	uint32_t i,j;
 	int retval;
 
@@ -458,11 +458,11 @@ static int image_elf_read_headers(struct image *image)
 	return ERROR_OK;
 }
 
-static int image_elf_read_section(struct image *image, int section, uint32_t offset, uint32_t size, uint8_t *buffer, uint32_t *size_read)
+static int image_elf_read_section(struct image *image, int section, uint32_t offset, uint32_t size, uint8_t *buffer, size_t *size_read)
 {
 	struct image_elf *elf = image->type_private;
 	Elf32_Phdr *segment = (Elf32_Phdr *)image->sections[section].private;
-	uint32_t read_size,really_read;
+	size_t read_size,really_read;
 	int retval;
 
 	*size_read = 0;
@@ -474,7 +474,7 @@ static int image_elf_read_section(struct image *image, int section, uint32_t off
 	{
 		/* maximal size present in file for the current segment */
 		read_size = MIN(size, field32(elf,segment->p_filesz)-offset);
-		LOG_DEBUG("read elf: size = 0x%" PRIx32 " at 0x%" PRIx32 "",read_size,
+		LOG_DEBUG("read elf: size = 0x%zu at 0x%" PRIx32 "", read_size,
 			field32(elf,segment->p_offset) + offset);
 		/* read initialized area of the segment */
 		if ((retval = fileio_seek(&elf->fileio, field32(elf,segment->p_offset) + offset)) != ERROR_OK)
@@ -797,7 +797,7 @@ int image_open(struct image *image, const char *url, const char *type_string)
 	return retval;
 };
 
-int image_read_section(struct image *image, int section, uint32_t offset, uint32_t size, uint8_t *buffer, uint32_t *size_read)
+int image_read_section(struct image *image, int section, uint32_t offset, uint32_t size, uint8_t *buffer, size_t *size_read)
 {
 	int retval;
 
diff --git a/src/target/image.h b/src/target/image.h
index 06d47bf87..0dac5baed 100644
--- a/src/target/image.h
+++ b/src/target/image.h
@@ -102,7 +102,7 @@ struct image_mot
 
 int image_open(struct image *image, const char *url, const char *type_string);
 int image_read_section(struct image *image, int section, uint32_t offset,
-		uint32_t size, uint8_t *buffer, uint32_t *size_read);
+		uint32_t size, uint8_t *buffer, size_t *size_read);
 void image_close(struct image *image);
 
 int image_add_section(struct image *image, uint32_t base, uint32_t size,
diff --git a/src/target/target.c b/src/target/target.c
index f141e933f..c00c2ed9d 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -2399,7 +2399,7 @@ static COMMAND_HELPER(parse_load_image_command_args, struct image *image,
 COMMAND_HANDLER(handle_load_image_command)
 {
 	uint8_t *buffer;
-	uint32_t buf_cnt;
+	size_t buf_cnt;
 	uint32_t image_size;
 	uint32_t min_address = 0;
 	uint32_t max_address = 0xffffffff;
@@ -2519,7 +2519,7 @@ COMMAND_HANDLER(handle_dump_image_command)
 	int retval = ERROR_OK;
 	while (size > 0)
 	{
-		uint32_t size_written;
+		size_t size_written;
 		uint32_t this_run_size = (size > 560) ? 560 : size;
 		retval = target_read_buffer(target, address, this_run_size, buffer);
 		if (retval != ERROR_OK)
@@ -2553,7 +2553,7 @@ COMMAND_HANDLER(handle_dump_image_command)
 static COMMAND_HELPER(handle_verify_image_command_internal, int verify)
 {
 	uint8_t *buffer;
-	uint32_t buf_cnt;
+	size_t buf_cnt;
 	uint32_t image_size;
 	int i;
 	int retval;
@@ -2674,7 +2674,7 @@ static COMMAND_HELPER(handle_verify_image_command_internal, int verify)
 			}
 		} else
 		{
-			command_print(cmd_ctx, "address 0x%08" PRIx32 " length 0x%08" PRIx32 "",
+			command_print(cmd_ctx, "address 0x%08" PRIx32 " length 0x%08zx",
 						  image.sections[i].base_address,
 						  buf_cnt);
 		}
@@ -4537,7 +4537,7 @@ static void free_fastload(void)
 COMMAND_HANDLER(handle_fast_load_image_command)
 {
 	uint8_t *buffer;
-	uint32_t buf_cnt;
+	size_t buf_cnt;
 	uint32_t image_size;
 	uint32_t min_address = 0;
 	uint32_t max_address = 0xffffffff;
diff --git a/src/target/xscale.c b/src/target/xscale.c
index 30ca3bf32..9e93c020c 100644
--- a/src/target/xscale.c
+++ b/src/target/xscale.c
@@ -2557,7 +2557,7 @@ static int xscale_read_instruction(struct target *target,
 	struct xscale_common *xscale = target_to_xscale(target);
 	int i;
 	int section = -1;
-	uint32_t size_read;
+	size_t size_read;
 	uint32_t opcode;
 	int retval;