[U-Boot] [RFC] arm926ejs: fix jump to RAM nand_boot

Heiko Schocher hs at denx.de
Tue Nov 2 09:55:46 CET 2010


Hello Wolfgang,

Wolfgang Denk wrote:
> Dear Heiko Schocher,
> 
> In message <4CCFAFE4.3000600 at denx.de> you wrote:
>> - preloader copies first page of nand (nand_spl code) to
>>   0xbb000000 (some cpu internal mem) and jumps to this address
>> - nand_spl does lowlevelinit, relocate itself to TEXT_BASE (nand_spl code)
> 
> Why is this relocation needed? I understand that this 0xbb000000

Thats the question to solve ... don;t know, why nand_spl code
on arm (and other architectures?) do this ... I try to have a look
to find out, if we can run the nand_spl code complete from
this address, and immedietaly copy u-boot from nand to ram ...

> address is determined by the given hardware ans as such always fix?

Yep.

>> But as codesize changes (and with it relocation address) this
>> is not a perfect solution.
> 
> Indeed. CONFIG_SYS_NAND_U_BOOT_SIZE should be dropped, and the avtual
> value should be derived from the actual U-Boot image building
> process.

Yep.

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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