From d7076627ee03a2945dc6c6a217a24cc943f2abe2 Mon Sep 17 00:00:00 2001
From: Pierre-Alexandre Meyer <pierre@mouraf.org>
Date: Wed, 26 Aug 2009 21:21:38 -0700
Subject: [PATCH] gpllib: add bootloader detection
MIME-Version: 1.0
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Given an (active) partition, look for a bootloader ID.

Syslinux prints a string (SYSLINUX or EXTLINUX) between bytes
3 and 10.

After some random tests, it seems that Windows™98/98SE and Windows™ME
put MSWIN4.1 at the same place. Internet seems to confirm it:

   http://www.geocities.com/thestarman3/asm/mbr/MSWin41BRinHexEd.htm

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
---
 com32/gplinclude/disk/bootloaders.h | 18 +++++++++++++++
 com32/gpllib/disk/bootloaders.c     | 46 +++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+)
 create mode 100644 com32/gplinclude/disk/bootloaders.h
 create mode 100644 com32/gpllib/disk/bootloaders.c

diff --git a/com32/gplinclude/disk/bootloaders.h b/com32/gplinclude/disk/bootloaders.h
new file mode 100644
index 0000000..6aec9b3
--- /dev/null
+++ b/com32/gplinclude/disk/bootloaders.h
@@ -0,0 +1,18 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2009 Pierre-Alexandre Meyer
+ *
+ *   This file is part of Syslinux, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+#ifndef __BOOTLOADERS_H_
+#define __BOOTLOADERS_H_
+
+#include <stdint.h>
+#include <disk/geom.h>
+#include <disk/partition.h>
+
+int get_bootloader_string(const struct driveinfo *, const struct part_entry *, char*, const int);
+#endif /* __BOOTLOADERS_H_ */
diff --git a/com32/gpllib/disk/bootloaders.c b/com32/gpllib/disk/bootloaders.c
new file mode 100644
index 0000000..4b3962a
--- /dev/null
+++ b/com32/gpllib/disk/bootloaders.c
@@ -0,0 +1,46 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2009 Pierre-Alexandre Meyer
+ *
+ *   This file is part of Syslinux, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <disk/bootloaders.h>
+#include <disk/common.h>
+#include <disk/geom.h>
+#include <disk/read.h>
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * get_bootloader_string - return a string describing the boot code in a
+ *			   bootsector
+ * @d:			driveinfo struct describing the drive
+ * @p:	partition to scan (usually the active one)
+ * @buffer:		pre-allocated buffer
+ * @buffer_size:	@buffer size
+ **/
+int get_bootloader_string(const struct driveinfo *d, const struct part_entry *p,
+			  char* buffer, const int buffer_size)
+{
+	char boot_sector[SECTOR * sizeof(char)];
+
+	if (read_sectors(d, &boot_sector, p->start_lba, 1) == -1)
+		return -1;
+	else {
+		if (!strncmp(boot_sector + 3, "SYSLINUX", 8))
+			strncpy(buffer, "SYSLINUX", buffer_size - 1);
+		else if (!strncmp(boot_sector + 3, "EXTLINUX", 8))
+			strncpy(buffer, "EXTLINUX", buffer_size - 1);
+		else if (!strncmp(boot_sector + 3, "MSWIN4.1", 8))
+			strncpy(buffer, "MSWIN4.1", buffer_size - 1);
+		else
+			return -1;
+		/* Add more... */
+
+		buffer[buffer_size - 1] = '\0';
+		return 0;
+	}
+}
-- 
2.7.4