add const keyword to some APIs

Add 'const' keyword to 'char *' parameters to allow command handlers to
pass constant string arguments.  These changes allow the 'args' command
handler to be changed to 'const' in a subsequent patch.

src/flash/flash.c

@@ -199,7 +199,7 @@ flash_bank_t *get_flash_bank_by_num(int num)
 }
 
 int flash_command_get_bank_by_num(
-	struct command_context_s *cmd_ctx, char *str, flash_bank_t **bank)
+	struct command_context_s *cmd_ctx, const char *str, flash_bank_t **bank)
 {
 	unsigned bank_num;
 	COMMAND_PARSE_NUMBER(uint, str, bank_num);

src/flash/flash.h

@@ -326,7 +326,7 @@ flash_bank_t *get_flash_bank_by_num(int num);
  * @returns ERROR_OK on success, or an error indicating the problem.
  */
 int flash_command_get_bank_by_num(struct command_context_s *cmd_ctx,
-		char *str, flash_bank_t **bank);
+		const char *str, flash_bank_t **bank);
 /**
  * Returns the flash bank like get_flash_bank_by_num(), without probing.
  * @param num The flash bank number.

src/flash/lpc2900.c

@@ -635,7 +635,7 @@ static int lpc2900_handle_read_custom_command( struct command_context_s *cmd_ctx
 
 	/* Try and open the file */
 	fileio_t fileio;
-	char *filename = args[1];
+	const char *filename = args[1];
 	int ret = fileio_open( &fileio, filename, FILEIO_WRITE, FILEIO_BINARY );
 	if( ret != ERROR_OK )
 	{
@@ -747,8 +747,8 @@ static int lpc2900_handle_write_custom_command( struct command_context_s *cmd_ct
 	image.base_address = 0;
 	image.start_address_set = 0;
 
-	char *filename = args[1];
+	const char *filename = args[1];
-	char *type = (argc >= 3) ? args[2] : NULL;
+	const char *type = (argc >= 3) ? args[2] : NULL;
 	retval = image_open(&image, filename, type);
 	if (retval != ERROR_OK)
 	{

src/flash/nand.c

@@ -304,7 +304,7 @@ nand_device_t *get_nand_device_by_num(int num)
 }
 
 int nand_command_get_device_by_num(struct command_context_s *cmd_ctx,
-		char *str, nand_device_t **device)
+		const char *str, nand_device_t **device)
 {
 	unsigned num;
 	COMMAND_PARSE_NUMBER(uint, str, num);

src/flash/nand.h

@@ -226,7 +226,7 @@ int nand_init(struct command_context_s *cmd_ctx);
 
 /// helper for parsing a nand device command argument string
 int nand_command_get_device_by_num(struct command_context_s *cmd_ctx,
-		char *str, nand_device_t **device);
+		const char *str, nand_device_t **device);
 
 
 #define		ERROR_NAND_DEVICE_INVALID		(-1100)

src/pld/pld.h

@@ -29,7 +29,7 @@ typedef struct pld_driver_s
 	char *name;
 	int (*register_commands)(struct command_context_s *cmd_ctx);
 	int (*pld_device_command)(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc, struct pld_device_s *pld_device);
-	int (*load)(struct pld_device_s *pld_device, char *filename);
+	int (*load)(struct pld_device_s *pld_device, const char *filename);
 } pld_driver_t;
 
 typedef struct pld_device_s

src/pld/virtex2.c

@@ -143,7 +143,7 @@ static int virtex2_read_stat(struct pld_device_s *pld_device, uint32_t *status)
 	return ERROR_OK;
 }
 
-static int virtex2_load(struct pld_device_s *pld_device, char *filename)
+static int virtex2_load(struct pld_device_s *pld_device, const char *filename)
 {
 	virtex2_pld_device_t *virtex2_info = pld_device->driver_priv;
 	xilinx_bit_file_t bit_file;

src/pld/xilinx_bit.c

@@ -75,7 +75,7 @@ static int read_section(FILE *input_file, int length_size, char section,
 	return ERROR_OK;
 }
 
-int xilinx_read_bit_file(xilinx_bit_file_t *bit_file, char *filename)
+int xilinx_read_bit_file(xilinx_bit_file_t *bit_file, const char *filename)
 {
 	FILE *input_file;
 	struct stat input_stat;

src/pld/xilinx_bit.h

@@ -33,6 +33,6 @@ typedef struct xilinx_bit_file_s
 	uint8_t *data;
 } xilinx_bit_file_t;
 
-int xilinx_read_bit_file(xilinx_bit_file_t *bit_file, char *filename);
+int xilinx_read_bit_file(xilinx_bit_file_t *bit_file, const char *filename);
 
 #endif /* XILINX_BIT_H */

src/target/image.c

@@ -44,7 +44,7 @@
 	((elf->endianness == ELFDATA2LSB)? \
 		le_to_h_u32((uint8_t*)&field):be_to_h_u32((uint8_t*)&field))
 
-static int autodetect_image_type(image_t *image, char *url)
+static int autodetect_image_type(image_t *image, const char *url)
 {
 	int retval;
 	fileio_t fileio;
@@ -106,7 +106,7 @@ static int autodetect_image_type(image_t *image, char *url)
 	return ERROR_OK;
 }
 
-static int identify_image_type(image_t *image, char *type_string, char *url)
+static int identify_image_type(image_t *image, const char *type_string, const char *url)
 {
 	if (type_string)
 	{
@@ -669,7 +669,7 @@ static int image_mot_buffer_complete(image_t *image)
 	return ERROR_IMAGE_FORMAT_ERROR;
 }
 
-int image_open(image_t *image, char *url, char *type_string)
+int image_open(image_t *image, const char *url, const char *type_string)
 {
 	int retval = ERROR_OK;
 

src/target/image.h

@@ -100,7 +100,7 @@ typedef struct image_mot_s
 	uint8_t *buffer;
 } image_mot_t;
 
-int image_open(image_t *image, char *url, char *type_string);
+int image_open(image_t *image, const char *url, const char *type_string);
 int image_read_section(image_t *image, int section, uint32_t offset,
 		uint32_t size, uint8_t *buffer, uint32_t *size_read);
 void image_close(image_t *image);

src/target/register.c

@@ -30,7 +30,8 @@
 
 reg_arch_type_t *reg_arch_types = NULL;
 
-reg_t* register_get_by_name(reg_cache_t *first, char *name, int search_all)
+reg_t* register_get_by_name(reg_cache_t *first,
+		const char *name, bool search_all)
 {
 	int i;
 	reg_cache_t *cache = first;

src/target/register.h

@@ -62,7 +62,8 @@ typedef struct reg_arch_type_s
 	struct reg_arch_type_s *next;
 } reg_arch_type_t;
 
-reg_t* register_get_by_name(reg_cache_t *first, char *name, int search_all);
+reg_t* register_get_by_name(reg_cache_t *first,
+		const char *name, bool search_all);
 reg_cache_t** register_get_last_cache_p(reg_cache_t **first);
 
 int register_reg_arch_type(int (*get)(reg_t *reg),

src/target/target.c

@@ -2928,7 +2928,7 @@ static void writeString(FILE *f, char *s)
 }
 
 /* Dump a gmon.out histogram file. */
-static void writeGmon(uint32_t *samples, uint32_t sampleNum, char *filename)
+static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filename)
 {
 	uint32_t i;
 	FILE *f = fopen(filename, "w");

src/xsvf/xsvf.c

@@ -202,7 +202,6 @@ static int handle_xsvf_command(struct command_context_s *cmd_ctx, char *cmd, cha
 	int		tdo_mismatch = 0;
 	int		result;
 	int		verbose = 1;
-	char		*filename;
 
 	bool		collecting_path = false;
 	tap_state_t	path[XSTATE_MAX_PATH];
@@ -226,7 +225,8 @@ static int handle_xsvf_command(struct command_context_s *cmd_ctx, char *cmd, cha
 		return ERROR_FAIL;
 	}
 
-	filename = args[1];		/* we mess with args starting point below, snapshot filename here */
+	/* we mess with args starting point below, snapshot filename here */
+	const char *filename = args[1];
 
 	if (strcmp(args[0], "plain") != 0)
 	{