r4543 - in developers/werner: . poke

[werner at docs.openmoko.org]

Author: werner
Date: 2008-07-20 22:07:34 +0200 (Sun, 20 Jul 2008)
New Revision: 4543

Added:
   developers/werner/poke/
   developers/werner/poke/Makefile
   developers/werner/poke/poke.c
Log:
Quick and dirty utility to peek into registers and to tweak them.



Added: developers/werner/poke/Makefile
===================================================================
--- developers/werner/poke/Makefile	                        (rev 0)
+++ developers/werner/poke/Makefile	2008-07-20 20:07:34 UTC (rev 4543)
@@ -0,0 +1,5 @@
+CC=arm-angstrom-linux-gnueabi-gcc
+
+CFLAGS=-Wall -g
+
+all:	poke

Added: developers/werner/poke/poke.c
===================================================================
--- developers/werner/poke/poke.c	                        (rev 0)
+++ developers/werner/poke/poke.c	2008-07-20 20:07:34 UTC (rev 4543)
@@ -0,0 +1,75 @@
+/*
+ * poke.c - Read or write any CPU register
+ *
+ * Copyright (C) 2008 by OpenMoko, Inc.
+ * Written by Werner Almesberger <werner at openmoko.org>
+ * All Rights Reserved
+ *  
+ * 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.
+ */
+
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+
+#define PAGE_SIZE 4096
+#define MEM(addr) (*(uint32_t *) (mem+((addr) & (PAGE_SIZE-1))))
+
+static volatile void *mem;
+
+
+/* ----- Command-line parsing ---------------------------------------------- */
+
+
+static void __attribute__((noreturn)) usage(const char *name)
+{
+	fprintf(stderr, "usage: %s hex_address [value]\n", name);
+	exit(1);
+}
+
+
+int main(int argc, char **argv)
+{
+	int fd;
+	char *end;
+	unsigned long addr;
+	uint32_t val;
+
+	fd = open("/dev/mem", O_RDWR);
+        if (fd < 0) {
+		perror("/dev/mem");
+		exit(1);
+	}
+	switch (argc) {
+	case 3:
+		val = strtoul(argv[2], &end, 0);
+		if (*end)
+			usage(*argv);
+		/* fall through */
+	case 2:
+		addr = strtoul(argv[1], &end, 16);
+		if (*end)
+			usage(*argv);
+		break;
+	default:
+		usage(*argv);
+	}
+	mem = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
+	    addr & ~(PAGE_SIZE-1));
+	if (mem == MAP_FAILED) {
+		perror("mmap");
+		exit(1);
+	}
+	if (argc == 2)
+		printf("0x%08lx\n", (unsigned long) MEM(addr));
+	else
+		MEM(addr) = val;
+	return 0;
+}