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authorJan-Derk Bakker <J.D.Bakker@its.tudelft.nl>2016-09-07 16:26:03 -0500
committerTimothy Pearson <tpearson@raptorengineering.com>2016-09-07 16:26:03 -0500
commitdd3695fad0ea8b6f46afc59e881ace932202104b (patch)
tree146380adb50b43d402b588e492cab3f9102b8651
downloaddevmem-aspeed-dd3695fad0ea8b6f46afc59e881ace932202104b.zip
devmem-aspeed-dd3695fad0ea8b6f46afc59e881ace932202104b.tar.gz
Initial import of stock devmem2 program from
http://free-electrons.com/pub/mirror/devmem2.c
-rw-r--r--devmem-aspeed.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/devmem-aspeed.c b/devmem-aspeed.c
new file mode 100644
index 0000000..7732ecb
--- /dev/null
+++ b/devmem-aspeed.c
@@ -0,0 +1,131 @@
+/*
+ * devmem2.c: Simple program to read/write from/to any location in memory.
+ *
+ * Copyright (C) 2000, Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
+ *
+ *
+ * This software has been developed for the LART computing board
+ * (http://www.lart.tudelft.nl/). The development has been sponsored by
+ * the Mobile MultiMedia Communications (http://www.mmc.tudelft.nl/)
+ * and Ubiquitous Communications (http://www.ubicom.tudelft.nl/)
+ * projects.
+ *
+ * The author can be reached at:
+ *
+ * Jan-Derk Bakker
+ * Information and Communication Theory Group
+ * Faculty of Information Technology and Systems
+ * Delft University of Technology
+ * P.O. Box 5031
+ * 2600 GA Delft
+ * The Netherlands
+ *
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <termios.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#define FATAL do { fprintf(stderr, "Error at line %d, file %s (%d) [%s]\n", \
+ __LINE__, __FILE__, errno, strerror(errno)); exit(1); } while(0)
+
+#define MAP_SIZE 4096UL
+#define MAP_MASK (MAP_SIZE - 1)
+
+int main(int argc, char **argv) {
+ int fd;
+ void *map_base, *virt_addr;
+ unsigned long read_result, writeval;
+ off_t target;
+ int access_type = 'w';
+
+ if(argc < 2) {
+ fprintf(stderr, "\nUsage:\t%s { address } [ type [ data ] ]\n"
+ "\taddress : memory address to act upon\n"
+ "\ttype : access operation type : [b]yte, [h]alfword, [w]ord\n"
+ "\tdata : data to be written\n\n",
+ argv[0]);
+ exit(1);
+ }
+ target = strtoul(argv[1], 0, 0);
+
+ if(argc > 2)
+ access_type = tolower(argv[2][0]);
+
+
+ if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1) FATAL;
+ printf("/dev/mem opened.\n");
+ fflush(stdout);
+
+ /* Map one page */
+ map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, target & ~MAP_MASK);
+ if(map_base == (void *) -1) FATAL;
+ printf("Memory mapped at address %p.\n", map_base);
+ fflush(stdout);
+
+ virt_addr = map_base + (target & MAP_MASK);
+ switch(access_type) {
+ case 'b':
+ read_result = *((unsigned char *) virt_addr);
+ break;
+ case 'h':
+ read_result = *((unsigned short *) virt_addr);
+ break;
+ case 'w':
+ read_result = *((unsigned long *) virt_addr);
+ break;
+ default:
+ fprintf(stderr, "Illegal data type '%c'.\n", access_type);
+ exit(2);
+ }
+ printf("Value at address 0x%X (%p): 0x%X\n", target, virt_addr, read_result);
+ fflush(stdout);
+
+ if(argc > 3) {
+ writeval = strtoul(argv[3], 0, 0);
+ switch(access_type) {
+ case 'b':
+ *((unsigned char *) virt_addr) = writeval;
+ read_result = *((unsigned char *) virt_addr);
+ break;
+ case 'h':
+ *((unsigned short *) virt_addr) = writeval;
+ read_result = *((unsigned short *) virt_addr);
+ break;
+ case 'w':
+ *((unsigned long *) virt_addr) = writeval;
+ read_result = *((unsigned long *) virt_addr);
+ break;
+ }
+ printf("Written 0x%X; readback 0x%X\n", writeval, read_result);
+ fflush(stdout);
+ }
+
+ if(munmap(map_base, MAP_SIZE) == -1) FATAL;
+ close(fd);
+ return 0;
+}
+
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