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authorH. Peter Anvin <hpa@linux.intel.com>2010-06-21 17:29:51 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2010-06-21 17:29:51 -0700
commit1d0c49827da98d852d42fadd56b073ad3d3f1faa (patch)
treef2509cf058e9d7bc3fed323283b16349cc29a162 /utils
parent7556a891b2f28617f6c95aa271aeaf29883d0981 (diff)
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memdiskfind: utility to find an mBFT and output phram parameters
A trivial Linux utility to search for mBFT and output its parameters in a form which can be used as input to the phram Linux kernel module. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'utils')
-rw-r--r--utils/Makefile5
-rw-r--r--utils/memdiskfind.c119
2 files changed, 123 insertions, 1 deletions
diff --git a/utils/Makefile b/utils/Makefile
index 43552d88..455eb828 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -20,7 +20,7 @@ include $(topdir)/MCONFIG
CFLAGS = $(GCCWARN) -Os -fomit-frame-pointer -D_FILE_OFFSET_BITS=64
LDFLAGS = -O2 -s
-TARGETS = mkdiskimage isohybrid gethostip
+TARGETS = mkdiskimage isohybrid gethostip memdiskfind
TARGETS += isohybrid.pl # about to be obsoleted
ASIS = keytab-lilo lss16toppm md5pass ppmtolss16 sha1pass syslinux2ansi \
pxelinux-options
@@ -52,6 +52,9 @@ isohybrid: isohybrid.o isohdpfx.o
gethostip: gethostip.o
$(CC) $(LDFLAGS) -o $@ $^
+memdiskfind: memdiskfind.o
+ $(CC) $(LDFLAGS) -o $@ $^
+
tidy dist:
rm -f *.o .*.d isohdpfx.c
diff --git a/utils/memdiskfind.c b/utils/memdiskfind.c
new file mode 100644
index 00000000..331bfb35
--- /dev/null
+++ b/utils/memdiskfind.c
@@ -0,0 +1,119 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2010 Intel Corporation; author: H. Peter Anvin
+ *
+ * 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, Inc., 51 Franklin St, Fifth Floor,
+ * Boston MA 02110-1301, USA; either version 2 of the License, or
+ * (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * memdiskfind.c
+ *
+ * Simple utility to search for a MEMDISK instance and output the parameters
+ * needed to use the "phram" driver in Linux to map it.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include "../memdisk/mstructs.h"
+
+#define MBFT_MIN_LENGTH (36+4+26)
+
+static bool valid_mbft(const struct mBFT *mbft, size_t space)
+{
+ uint8_t csum;
+ size_t i;
+
+ if (memcmp(mbft->acpi.signature, "mBFT", 4))
+ return false;
+
+ if (mbft->acpi.length < MBFT_MIN_LENGTH)
+ return false;
+
+ if (mbft->acpi.length > space)
+ return false;
+
+ if ((size_t)mbft->acpi.length != (size_t)mbft->mdi.bytes + 36+4)
+ return false;
+
+ csum = 0;
+ for (i = 0; i < mbft->acpi.length; i++)
+ csum += ((const uint8_t *)mbft)[i];
+
+ if (csum)
+ return false;
+
+ return true;
+}
+
+static void output_params(const struct mBFT *mbft)
+{
+ printf("%u,%u\n", mbft->mdi.diskbuf, mbft->mdi.disksize);
+}
+
+int main(int argc, char *argv[])
+{
+ const char *map;
+ int memfd;
+ uint16_t fbm;
+ const char *ptr, *end;
+ size_t page = sysconf(_SC_PAGESIZE);
+ size_t mapbase, maplen;
+ int err = 1;
+
+ (void)argc;
+
+ memfd = open("/dev/mem", O_RDONLY);
+ if (memfd < 0) {
+ fprintf(stderr, "%s: cannot open /dev/mem: %s\n",
+ argv[0], strerror(errno));
+ return 2;
+ }
+
+ map = mmap(NULL, page, PROT_READ, MAP_SHARED, memfd, 0);
+ if (map == MAP_FAILED) {
+ fprintf(stderr, "%s: cannot map page 0: %s\n",
+ argv[0], strerror(errno));
+ return 2;
+ }
+
+ fbm = *(uint16_t *)(map + 0x413);
+
+ munmap((void *)map, 4096);
+
+ mapbase = (fbm << 10) & ~(page - 1);
+ maplen = 0xa0000 - mapbase;
+ map = mmap(NULL, maplen, PROT_READ, MAP_SHARED, memfd, mapbase);
+ if (map == MAP_FAILED) {
+ fprintf(stderr, "%s: cannot map base memory: %s\n",
+ argv[0], strerror(errno));
+ exit(1);
+ }
+
+ ptr = map + ((fbm << 10) & (page - 1));
+ end = map + (0xa0000 - mapbase);
+ while (ptr < end) {
+ if (valid_mbft((const struct mBFT *)ptr, end-ptr)) {
+ output_params((const struct mBFT *)ptr);
+ err = 0;
+ break;
+ }
+ ptr += 16;
+ }
+
+ munmap((void *)map, maplen);
+
+ return err;
+}