replace the ugly rb532 cmdline hack with a cleaner one that does not depend on magic offsets

SVN-Revision: 5699

1 files changed, 80 insertions, 0 deletions

diff --git a/target/linux/rb532-2.6/src/patch-cmdline.c b/target/linux/rb532-2.6/src/patch-cmdline.c
new file mode 100644
index 0000000..d4636f7
--- /dev/null
+++ b/target/linux/rb532-2.6/src/patch-cmdline.c
@@ -0,0 +1,80 @@
+/*
+ * patch-cmdline.c - patch the kernel command line on rb532
+ *
+ * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
+ *
+ * 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.
+ *
+ * $Id:$
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <string.h>
+
+#define SEARCH_SPACE	(16 * 1024)
+#define CMDLINE_MAX		512
+
+int main(int argc, char **argv)
+{
+	int fd, found = 0, len, ret = -1;
+	char *ptr, *p;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s <file> <cmdline>\n", argv[0]);
+		goto err1;
+	}
+	len = strlen(argv[2]);
+	if (len + 9 > CMDLINE_MAX) {
+		fprintf(stderr, "Command line string too long\n");
+		goto err1;
+	}
+	
+	if (((fd = open(argv[1], O_RDWR)) < 0) ||
+		(ptr = (char *) mmap(0, SEARCH_SPACE + CMDLINE_MAX, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == (void *) (-1)) {
+		fprintf(stderr, "Could not open kernel image");
+		goto err2;
+	}
+	
+	for (p = ptr; p < (ptr + SEARCH_SPACE); p += 4) {
+		if (memcmp(p, "CMDLINE:", 8) == 0) {
+			found = 1;
+			p += 8;
+			break;
+		}
+	}
+	if (!found) {
+		fprintf(stderr, "Command line marker not found!\n");
+		goto err3;
+	}
+
+	memset(p, 0, CMDLINE_MAX - 8);
+	strcpy(p, argv[2]);
+	msync(p, CMDLINE_MAX, MS_SYNC|MS_INVALIDATE);
+	ret = 0;
+
+err3:
+	munmap((void *) ptr, len);
+err2:
+	if (fd > 0)
+		close(fd);
+err1:
+	return ret;
+}