[U-Boot-Users] boot kernel from flash

[Wolfgang Denk]

In message <1115544065.6600.7.camel at localhost> you wrote:
>
> 1.	erase 0x100000 0x3fffff		(0x100000--0x3fffff is flash room for kernel)
> 2.	loadb 0x100000

You cannot load directly to flash. Youmust always write to RAM first,
and then use the "cp" command (or cp.b etc.) to write to flash.

> 3.	using kermit to transfer uImage from ttyS0
> 4.	using "iminfo 0x100000", and i found "Bad Magic Number"

This means that your image was not written to flash (which is  not  a
surprise,  as "loadb" is NOT listed as a flash programming command in
the manual -- ummm.... You did read the manual,  didn't  you?  Before
posting???

> 5.	setenv bootcmd bootm 0x100000
> 6.	boot, but i found 
> 	"## Booting image at 00100000 ...
> 	Bad Magic Number"

This is to be expeted,  too.  If  there  was  no  valid  image  after
download, it would take a certain amount of magic to be there now.

> i used this uImage file to boot kernel from memory, so kernel image is
> right! and i tried to use "tftp 0x100000" to download image to flash,and
> the result is identical.

Of course. Because "tftp" is NOT listed as a flash programming command in
the manual .. etc.

I REALLY recommend you to READ the manual. 

> and i did more testing:
> 1.	tftp 0x10000000		(0x10000000 is ram address)
> 2.	erase 0x100000 0x3fffff
> 3.	cp.b 0x10000000 0x100000 $(filesize)
> 4.	bootm 0x100000
> 
> the kernel boot successed! ...

Of course this works. That's the documented way to do things.


> ... but if i rebooted, and "bootm 0x100000", the kernel stoped when mounted nfsroot fs.
> the boot information was:
> ..............................
> <6>Freeing initrd memory: 4096K
> Freeing initrd memory: 4096K
> <5>Looking up port of RPC 100003/2 on 172.16.6.79
> Looking up port of RPC 100003/2 on 172.16.6.79
> 
> (172.16.6.79 is nfsroot server)

Probably a configuration problem with your NFS server?

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
I have been over into the future, and it works.
                - Lincoln Steffens in _Letters_ (1938) vol. 1, p. 463