[U-Boot-Users] U-Boot-NG ?

[Wolfgang Denk]

In message <20070703000910.GA15081 at pengutronix.de> you wrote:
>
> > You don't? How do you uncompress an image then?
> 
> On Arm by default zImages are used to generate the uImage, so the kernel
> decompresses itself.

For the Linux kernel, maybe. But there are many more things than just
Linux. Think for example about FPGA images, etc.

> > Do you mean you don't relocate the code any more?
> 
> It still gets copied from the address U-Boot starts (Flash) to RAM, but
> pointer offsets are not recalculated. This means that you must not use
> statically initialized pointers during startup since the code is not
> running at its link address.

Are you doing this for all architectures now? 

> The Arm part has done this for years. On PowerPC we have the luxury of

Yes, and this is my major critique to the  ARM  (and  the  MIPS,  and
maybe  other)  ports.  We  should  fix  this. Like on PowerPC, U-Boot
should always be copied  to  the  upper  end  of  RAM  instead  of  a
precalculated address, as this cannot cope with different RAM sizes.

> having SRAM, so we can setup a stack and do SDRAM initialization in C
> before jumping to RAM.

Not all PowerPC processors have on-chip or other static RAM; in  some
cases  we  use  (for  example)  the  data  cache  as  memory. Similar
techniqes should be possible on all architectures.

Best regards,

Wolfgang Denk

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