[LinuxBIOS] patch: extending LAR, and removing elf from linuxbios (it is not needed)

[Stefan Reinauer]

* ron minnich <rminnich at gmail.com> [070828 06:16]:
> ===================================================================
> --- lib/lar.c	(revision 480)
> +++ lib/lar.c	(working copy)
> @@ -42,9 +49,31 @@
>  
>  	for (walk = archive->start;
>  	     (walk - 1) < (char *)(archive->start + archive->len - 1 ); walk += 16) {
> -		if (strcmp(walk, MAGIC) != 0)
> +		/* I am leaving this code in here because it is so dangerous. MAGIC is
> + 		 * #define'd to a string. That string lives in data space. All of the 1M linuxbios 
> + 		 * image is a LAR file. Therefore, this search can walk ALL of linuxbios. 
> + 		 * IF the MAGIC string (in code space) just happens to be 16-byte aligned, 
> + 		 * Then the strcmp will succeed, and you will match a non-LAR entry, 
> + 		 * and you are screwed. can this happen? YES!
> + 		 * LAR: Attempting to open 'fallback/initram'.
> + 		 * LAR: Start 0xfff00000 len 0x100000
> + 		 * LAR: current filename is normal/payload
> + 		 * LAR: current filename is normal/option_table
> + 		 * LAR: current filename is normal/stage2
> + 		 * LAR: current filename is normal/initram
> + 		 * LAR: current filename is R: it matches %s @ %p
> + 		 * That garbage is there because the pointer is in the middle of a bunch 
> + 		 * of non-null-terminated junk. The fix is easy, as you can see. 

I think the fix could be even simpler. Instead, if the first header is found,
the second header should be searched _after_ the end of the first file
in the LAR archive. Going through all of the ROM including the data
itself is plain stupid. I remember we did not do this in the beginning,
but we broke it since then.


> +		if (walk[0] != 'L')
>  			continue;
>  
> +		if (strcmp(&walk[1], MAGIC) != 0)
> +			continue;


> +	printf("  -e pre-parse the payload ELF into LAR segments. Recommended\n\n");

> +		{"parseelf", 1, 0, 'p'},

> -	while ((opt = getopt_long(argc, argv, "acC:xls:b:vVh?",

--parseelf will not work like that. 

> +/* NOTE -- This and the linuxbios lar.h are NOT IN SYNC. Be careful. */

What do you mean, by "not in sync"?

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