diff options
| -rw-r--r-- | toys/other/devmem.c | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/toys/other/devmem.c b/toys/other/devmem.c index ced6c518..920d8563 100644 --- a/toys/other/devmem.c +++ b/toys/other/devmem.c @@ -10,9 +10,8 @@ config DEVMEM help usage: devmem ADDR [WIDTH [DATA]] - Read/write physical address via /dev/mem. - - WIDTH is 1, 2, 4, or 8 bytes (default 4). + Read/write physical address. WIDTH is 1, 2, 4, or 8 bytes (default 4). + Prefix ADDR with 0x for hexadecimal, output is in same base as address. */ #define FOR_devmem @@ -21,14 +20,15 @@ config DEVMEM void devmem_main(void) { int writing = toys.optc == 3, page_size = sysconf(_SC_PAGESIZE), bytes = 4,fd; - unsigned long long addr = atolx(toys.optargs[0]), data = 0, map_off, map_len; + unsigned long long data = 0, map_off, map_len; + unsigned long addr = atolx(*toys.optargs); void *map, *p; // WIDTH? if (toys.optc>1) { int i; - if (strlen(toys.optargs[1])!=1 || (i=stridx("1248", *toys.optargs[1]))==-1) + if ((i=stridx("1248", *toys.optargs[1]))==-1 || toys.optargs[1][1]) error_exit("bad width: %s", toys.optargs[1]); bytes = 1<<i; } @@ -37,13 +37,16 @@ void devmem_main(void) if (writing) data = atolx_range(toys.optargs[2], 0, (1ULL<<(8*bytes))-1); // Map in just enough. - fd = xopen("/dev/mem", (writing ? O_RDWR : O_RDONLY) | O_SYNC); - map_off = addr & ~(page_size - 1); - map_len = (addr+bytes-map_off); - map = xmmap(NULL, map_len, writing ? PROT_WRITE : PROT_READ, MAP_SHARED, fd, - map_off); - p = map + (addr & (page_size - 1)); - close(fd); + if (CFG_TOYBOX_FORK) { + fd = xopen("/dev/mem", (writing ? O_RDWR : O_RDONLY) | O_SYNC); + + map_off = addr & ~(page_size - 1); + map_len = (addr+bytes-map_off); + map = xmmap(0, map_len, writing ? PROT_WRITE : PROT_READ, MAP_SHARED, fd, + map_off); + p = map + (addr & (page_size - 1)); + close(fd); + } else p = (void *)addr; // Not using peek()/poke() because registers care about size of read/write if (writing) { @@ -56,8 +59,9 @@ void devmem_main(void) else if (bytes == 2) data = *(unsigned short *)p; else if (bytes == 4) data = *(unsigned int *)p; else if (bytes == 8) data = *(unsigned long long *)p; - printf("%#0*llx\n", bytes*2, data); + printf((!strchr(*toys.optargs, 'x')) ? "%0*lld\n" : "0x%0*llx\n", + bytes*2, data); } - munmap(map, map_len); + if (CFG_TOYBOX_FORK) munmap(map, map_len); } |