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diff -Nrup include/applets.h include/applets.h
--- include/applets.h 2008-04-26 18:22:37.000000000 +0000
+++ include/applets.h 2008-04-26 18:19:53.000000000 +0000
@@ -121,6 +121,7 @@ USE_DEALLOCVT(APPLET(deallocvt, _BB_DIR_
USE_DELGROUP(APPLET_ODDNAME(delgroup, deluser, _BB_DIR_BIN, _BB_SUID_NEVER, delgroup))
USE_DELUSER(APPLET(deluser, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_DEVFSD(APPLET(devfsd, _BB_DIR_SBIN, _BB_SUID_NEVER))
+USE_DEVMEM(APPLET(devmem, _BB_DIR_SBIN, _BB_SUID_NEVER))
USE_DF(APPLET(df, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_APP_DHCPRELAY(APPLET(dhcprelay, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
USE_DIFF(APPLET(diff, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
diff -Nrup include/usage.h include/usage.h
--- include/usage.h 2007-12-21 22:00:31.000000000 +0000
+++ include/usage.h 2008-04-26 18:21:59.000000000 +0000
@@ -630,6 +630,16 @@
"\n and processing synthetic REGISTER events," \
"\n do not poll for events")
+#define devmem_trivial_usage \
+ "{ address } [ type [ data ] ]"
+
+#define devmem_full_usage \
+ "Read/Write from physical addresses" \
+ "\n\nUsage: devmem { address } [ type [ data ] ]" \
+ "\n address : memory address to act upon" \
+ "\n type : access operation type : [b]yte, [h]alfword, [w]ord" \
+ "\n data : data to be written"
+
/* -k is accepted but ignored for !HUMAN_READABLE,
* but we won't mention this (unimportant) */
#if ENABLE_FEATURE_HUMAN_READABLE || ENABLE_FEATURE_DF_INODE
diff -Nrup miscutils/Config.in miscutils/Config.in
--- miscutils/Config.in 2007-12-21 22:00:31.000000000 +0000
+++ miscutils/Config.in 2008-04-26 17:54:51.000000000 +0000
@@ -120,6 +120,13 @@ config FEATURE_DEVFS
/dev/loop0. If your /dev directory has normal names instead of
devfs names, you don't want this.
+config DEVMEM
+ bool "devmem"
+ default y
+ help
+ devmem is a small program that reads and writes from physical
+ memory using /dev/mem.
+
config EJECT
bool "eject"
default n
diff -Nrup miscutils/Kbuild miscutils/Kbuild
--- miscutils/Kbuild 2007-12-21 22:00:31.000000000 +0000
+++ miscutils/Kbuild 2008-04-26 17:56:36.000000000 +0000
@@ -12,6 +12,7 @@ lib-$(CONFIG_CROND) += crond.o
lib-$(CONFIG_CRONTAB) += crontab.o
lib-$(CONFIG_DC) += dc.o
lib-$(CONFIG_DEVFSD) += devfsd.o
+lib-$(CONFIG_DEVMEM) += devmem.o
lib-$(CONFIG_EJECT) += eject.o
lib-$(CONFIG_HDPARM) += hdparm.o
lib-$(CONFIG_LAST) += last.o
diff -Nrup miscutils/devmem.c miscutils/devmem.c
--- miscutils/devmem.c 1970-01-01 00:00:00.000000000 +0000
+++ miscutils/devmem.c 2008-04-26 18:18:30.000000000 +0000
@@ -0,0 +1,65 @@
+/*
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Copyright (C) 2000, Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
+ * Copyright (C) 2008, BusyBox Team. -solar 4/26/08
+ */
+
+#include "libbb.h"
+
+#define DEVMEM_MAP_SIZE 4096UL
+#define DEVMEM_MAP_MASK (DEVMEM_MAP_SIZE - 1)
+
+int devmem_main(int argc, char **argv) {
+ void *map_base, *virt_addr;
+ unsigned long read_result, writeval;
+ off_t target;
+ int fd, access_type = 'w';
+
+ if (argc < 2)
+ bb_show_usage();
+
+ target = bb_strtoul(argv[1], 0, 0);
+
+ if (argc > 2)
+ access_type = tolower(argv[2][0]);
+
+ fd = xopen("/dev/mem", O_RDWR | O_SYNC);
+
+ if ((map_base = mmap(0, DEVMEM_MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, target & ~DEVMEM_MAP_MASK)) == MAP_FAILED)
+ bb_perror_msg_and_die("mmap");
+
+ printf("Memory mapped at address %p.\n", map_base);
+
+ virt_addr = map_base + (target & DEVMEM_MAP_MASK);
+ if (access_type == 'b')
+ read_result = *((unsigned char *) virt_addr);
+ else if (access_type == 'h')
+ read_result = *((unsigned short *) virt_addr);
+ else if (access_type == 'w')
+ read_result = *((unsigned long *) virt_addr);
+ else {
+ fprintf(stderr, "Illegal data type '%c'\n", access_type);
+ exit(EXIT_FAILURE);
+ }
+ printf("Value at address 0x%X (%p): 0x%X\n", target, virt_addr, read_result);
+
+ if (argc > 3) {
+ writeval = bb_strtoul(argv[3], 0, 0);
+ if (access_type == 'b') {
+ *((unsigned char *) virt_addr) = writeval;
+ read_result = *((unsigned char *) virt_addr);
+ } else if (access_type == 'h') {
+ *((unsigned short *) virt_addr) = writeval;
+ read_result = *((unsigned short *) virt_addr);
+ } else if (access_type == 'w') {
+ *((unsigned long *) virt_addr) = writeval;
+ read_result = *((unsigned long *) virt_addr);
+ }
+ printf("Written 0x%X; readback 0x%X\n", writeval, read_result);
+ }
+
+ if (munmap(map_base, DEVMEM_MAP_SIZE) == -1)
+ bb_perror_msg_and_die("munmap");
+ close(fd);
+ fflush_stdout_and_exit(EXIT_SUCCESS);
+}
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