[U-Boot] [PATCH 1/2 v2] cramfs: make cramfs usable on non NOR flash

Heiko Schocher hs at denx.de
Thu Jan 28 08:30:44 CET 2010


Hello Wolfgang,

Wolfgang Denk wrote:
> In message <4B5FEB9E.3040908 at denx.de> you wrote:
>> [PATCH 1/2] cramfs: make cramfs usable without a NOR flash
> 
> I'm afraid I still don't understand how this is supposed to work.
> 
> Where would you store the cramfs on a system "without a NOR flash"?
> Are we talking about - say - a NAND storage device then?

The cramfs image is located in RAM (where it first was copied from
whenever), and then files are read from it with the "cramfsload"
command ...

>> @@ -119,7 +121,11 @@ int do_cramfs_load(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
>>  	dev.id = &id;
>>  	part.dev = &dev;
>>  	/* fake the address offset */
>> +#if !defined(CONFIG_SYS_NO_FLASH)
>>  	part.offset = addr - flash_info[id.num].start[0];
>> +#else
>> +	part.offset = addr;
>> +#endif
> 
> I understand that we now can have the cramfs image either in NOR flash
> _or_ in NAND.

No, we can have it in ROM or in RAM.

> What about systems that have both NOR _and_ NAND?

Are there such systems, with cramfs support? Actual cramfs support
in mainline is only for NOR devices ...

But, I think, it should work to extract a file from a cramfs stored
on a NAND on such systems with the "cramfsload" command ... if not,
the cramfs image could be copied from NAND to RAM, and then it
works ...

bye
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany


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