Re: [PATCH] ntldr support

[Christian Franke <Christian.Franke@t-online.de>]

Robert Millan wrote:
>> It probably would make sense that the 'ntldr' command does simple  
>> signature checks and fail on unknown files unless '--force' is specified.
>>     
>
> You mean checking for the PE signature?  Yes, this would be nice too.
>
>   

A check of the first byte (jmp, 0xe9) and some file size range check 
(e.g. 0x30000...0x40000) may be enough for a first ntldr command. May 
also work for bootmgr.exe.

EXE ("MZ") and PE headers appear at larger offsets:

ntldr from XP SP2: size 251184, EXE header at 0x4d30, PE at 0x4e00
ntldr from XP SP3: size 251712, EXE header at 0x4d40, PE at 0x4e10
bootmgr.exe from Vista: ???


grub4dos checks for ntldr as follows:
- file starts with 0xe9, 0x??, 0x01,
- first sector does not end with bootsector signature 0x55,0xaa,
- file size exceeds 0x30000.

-- 
Regards
Christian Franke