u-boot/common/cmd_sf.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

195 lines
3.9 KiB
C

/*
* Command for accessing SPI flash.
*
* Copyright (C) 2008 Atmel Corporation
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <spi_flash.h>
#include <asm/io.h>
#ifndef CONFIG_SF_DEFAULT_SPEED
# define CONFIG_SF_DEFAULT_SPEED 1000000
#endif
#ifndef CONFIG_SF_DEFAULT_MODE
# define CONFIG_SF_DEFAULT_MODE SPI_MODE_3
#endif
static struct spi_flash *flash;
static int do_spi_flash_probe(int argc, char * const argv[])
{
unsigned int bus = 0;
unsigned int cs;
unsigned int speed = CONFIG_SF_DEFAULT_SPEED;
unsigned int mode = CONFIG_SF_DEFAULT_MODE;
char *endp;
struct spi_flash *new;
if (argc < 2)
goto usage;
cs = simple_strtoul(argv[1], &endp, 0);
if (*argv[1] == 0 || (*endp != 0 && *endp != ':'))
goto usage;
if (*endp == ':') {
if (endp[1] == 0)
goto usage;
bus = cs;
cs = simple_strtoul(endp + 1, &endp, 0);
if (*endp != 0)
goto usage;
}
if (argc >= 3) {
speed = simple_strtoul(argv[2], &endp, 0);
if (*argv[2] == 0 || *endp != 0)
goto usage;
}
if (argc >= 4) {
mode = simple_strtoul(argv[3], &endp, 16);
if (*argv[3] == 0 || *endp != 0)
goto usage;
}
new = spi_flash_probe(bus, cs, speed, mode);
if (!new) {
printf("Failed to initialize SPI flash at %u:%u\n", bus, cs);
return 1;
}
if (flash)
spi_flash_free(flash);
flash = new;
printf("%u KiB %s at %u:%u is now current device\n",
flash->size >> 10, flash->name, bus, cs);
return 0;
usage:
puts("Usage: sf probe [bus:]cs [hz] [mode]\n");
return 1;
}
static int do_spi_flash_read_write(int argc, char * const argv[])
{
unsigned long addr;
unsigned long offset;
unsigned long len;
void *buf;
char *endp;
int ret;
if (argc < 4)
goto usage;
addr = simple_strtoul(argv[1], &endp, 16);
if (*argv[1] == 0 || *endp != 0)
goto usage;
offset = simple_strtoul(argv[2], &endp, 16);
if (*argv[2] == 0 || *endp != 0)
goto usage;
len = simple_strtoul(argv[3], &endp, 16);
if (*argv[3] == 0 || *endp != 0)
goto usage;
buf = map_physmem(addr, len, MAP_WRBACK);
if (!buf) {
puts("Failed to map physical memory\n");
return 1;
}
if (strcmp(argv[0], "read") == 0)
ret = spi_flash_read(flash, offset, len, buf);
else
ret = spi_flash_write(flash, offset, len, buf);
unmap_physmem(buf, len);
if (ret) {
printf("SPI flash %s failed\n", argv[0]);
return 1;
}
return 0;
usage:
printf("Usage: sf %s addr offset len\n", argv[0]);
return 1;
}
static int do_spi_flash_erase(int argc, char * const argv[])
{
unsigned long offset;
unsigned long len;
char *endp;
int ret;
if (argc < 3)
goto usage;
offset = simple_strtoul(argv[1], &endp, 16);
if (*argv[1] == 0 || *endp != 0)
goto usage;
len = simple_strtoul(argv[2], &endp, 16);
if (*argv[2] == 0 || *endp != 0)
goto usage;
ret = spi_flash_erase(flash, offset, len);
if (ret) {
printf("SPI flash %s failed\n", argv[0]);
return 1;
}
return 0;
usage:
puts("Usage: sf erase offset len\n");
return 1;
}
static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
const char *cmd;
/* need at least two arguments */
if (argc < 2)
goto usage;
cmd = argv[1];
if (strcmp(cmd, "probe") == 0)
return do_spi_flash_probe(argc - 1, argv + 1);
/* The remaining commands require a selected device */
if (!flash) {
puts("No SPI flash selected. Please run `sf probe'\n");
return 1;
}
if (strcmp(cmd, "read") == 0 || strcmp(cmd, "write") == 0)
return do_spi_flash_read_write(argc - 1, argv + 1);
if (strcmp(cmd, "erase") == 0)
return do_spi_flash_erase(argc - 1, argv + 1);
usage:
cmd_usage(cmdtp);
return 1;
}
U_BOOT_CMD(
sf, 5, 1, do_spi_flash,
"SPI flash sub-system",
"probe [bus:]cs [hz] [mode] - init flash device on given SPI bus\n"
" and chip select\n"
"sf read addr offset len - read `len' bytes starting at\n"
" `offset' to memory at `addr'\n"
"sf write addr offset len - write `len' bytes from memory\n"
" at `addr' to flash at `offset'\n"
"sf erase offset len - erase `len' bytes from `offset'"
);