Detect VBR bootloader

Detect if a partition has a bootloader installed on its Volume Boot
Record.

image_creator/bootloader.py

@@ -152,4 +152,126 @@ def mbr_bootinfo(mbr):
 
     return MBR_LDR[ret]
 
+
+# Volume Boot Record Bootloaders
+VBR_LDR = [
+    # GRUB Legacy
+    "grub1",        # 0
+    # GRUB 2
+    "grub2",
+    # LILO (LInux LOader)
+    "lilo"
+    # SYSLINUX
+    "syslinux",
+    # Windows
+    "windows",
+    # FreeBSD's boot1 (First sector of FreeBSD slice)
+    "freebsd",      # 5
+    # NetBSD's PBR
+    "netbsd",
+    # OpenBSD
+    "openbsd",
+    # ReactOS
+    "reactos",
+    # FreeDOS
+    "freedos",
+    # MS-DOS
+    "msdos",        # 10
+    # HP Recovery
+    "hp",
+    # Dell Utility/Recovery
+    "dell",
+    # ISOhybrid
+    "isohybrid",
+    # Grub4Dos
+    "grub4dos",
+    # BootIt Boot Manager
+    "bootit",       # 15
+    # Acronis Secure Zone
+    "acronis_sz",
+]
+
+# 2-byte VBR "no bootloader" signature
+VBR_SIG2_NONE = (
+    "\x00\x00",
+    "\x55\xcd",
+    "\x69\x6e",
+    "\x6f\x6e",
+)
+
+# 2-byte VBR signature
+VBR_SIG2 = {
+    "\x00\x20": 1,
+    "\x00\x69": 13,
+    "\x01\x0f": 11,
+    "\x02\x11": 12,
+    "\x04\x88": 1,
+    "\x06\x89": 3,
+    "\x07\x34": 10,
+    "\x07\x45": 4,
+    "\x08\x9e": 10,
+    "\x08\xcd": 4,
+    "\x08\xc7": 7,
+    "\x0b\x60": 12,
+    "\x0b\xd0": 4,
+    "\x0e\x00": 12,
+    "\x0f\xb6": 13,
+    "\x2a\x00": 8,
+    "\x2d\x5e": 10,
+    "\x31\xc0": 3,
+    "\x3c\x9a": 6,
+    "\x40\x7c": 3,
+    "\x42\x16": 14,
+    "\x44\x45": 12,
+    "\x48\xb4": 1,
+    "\x52\x72": 0,
+    "\x56\x26": 14,
+    "\x63\x8b": 9,
+    "\x66\x16": 4,
+    "\x69\x74": 15,
+    "\x6a\x02": 5,
+    "\x6f\x65": 15,
+    "\x74\x05": 4,
+    "\x7c\x3c": 1,
+    "\x7c\xc6": 4,
+    "\x7e\x1e": 14,
+    "\x80\x53": 2,
+    "\x8a\x56": 16,
+    "\x83\xe1": 13,
+    "\x8e\xc0": 4,
+    "\x8e\xd0": 12,
+    "\xaa\x75": 0,
+    "\xb1\x06": 3,
+    "\xb6\x00": 12,
+    "\xb6\xc6": 13,
+    "\xb6\xd1": 4,
+    "\xe8\x79": 13,
+    "\xe9\xd8": 4,
+    "\xf6\xc1": 4,
+    "\xfa\x33": 4,
+}
+
+# 4-byte VBR signature
+VBR_SIG4 = {
+    "\x55\xaa\x75\x0a": 14,
+    "\x55\xaa\x75\x06": 4,
+    "\x78\x15\xb1\x06": 3,
+}
+
+
+def vbr_bootinfo(vbr):
+    """Inspect a Volume Boot Record and return the installed bootloader"""
+    if vbr[0x80:0x82] in VBR_SIG2_NONE:
+        return "none"
+
+    try:
+        ret = VBR_SIG2[vbr[0x80:0x82]]
+    except KeyError:
+        try:
+            ret = VBR_SIG4[vbr[0x80:0x84]]
+        except KeyError:
+            return "unknown"
+
+    return MBR_LDR[ret]
+
 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :