1 files changed, 158 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/utils/memdiskfind.c b/contrib/syslinux-4.02/utils/memdiskfind.c
new file mode 100644
index 0000000..decc788
--- /dev/null
+++ b/contrib/syslinux-4.02/utils/memdiskfind.c
@@ -0,0 +1,158 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   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)
+{
+    int sector_shift = mbft->mdi.sector_shift;
+
+    if (!sector_shift)
+	sector_shift = 9;
+
+    printf("%#x,%#x\n",
+	   mbft->mdi.diskbuf, mbft->mdi.disksize << sector_shift);
+}
+
+static size_t memlimit(void)
+{
+    char txtline[256], user[256];
+    size_t maxram = 0;
+    unsigned long long start, end;
+    FILE *iomem;
+
+    iomem = fopen("/proc/iomem", "r");
+    if (!iomem)
+	return 0;
+
+    while (fgets(txtline, sizeof txtline, iomem) != NULL) {
+	if (sscanf(txtline, "%llx-%llx : %[^\n]", &start, &end, user) != 3)
+	    continue;
+	if (strcmp(user, "System RAM"))
+	    continue;
+	if (start >= 0xa0000)
+	    continue;
+	maxram = (end >= 0xa0000) ? 0xa0000 : end+1;
+    }
+    fclose(iomem);
+
+    return maxram;
+}
+
+int main(int argc, char *argv[])
+{
+    const char *map;
+    int memfd;
+    size_t fbm;
+    const char *ptr, *end;
+    size_t page = sysconf(_SC_PAGESIZE);
+    size_t mapbase, maplen;
+    int err = 1;
+
+    (void)argc;
+
+    mapbase = memlimit() & ~(page - 1);
+    if (!mapbase)
+	return 2;
+
+    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) << 10;
+    if (fbm < mapbase)
+	fbm = mapbase;
+
+    munmap((void *)map, page);
+
+    if (fbm < 64*1024 || fbm >= 640*1024)
+	return 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));
+	return 2;
+    }
+
+    ptr = map + (fbm - mapbase);
+    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;
+}