[U-Boot] UBoot porting to cortex-m3 based SoC

[Wolfgang Denk]

Dear Shawn Jin,

In message <c3d0340b0912202130s808265fr21afc4f6be866e at mail.gmail.com> you wrote:
>
> Before starting the project I'd like to have some advices from the community
> about the feasibility of porting U-Boot/ucLinux to a cortex-m3 based SoC
> with limited resources (up to 512K flash, up to 64K SRAM). I limit my
> questions to U-Boot only and will post similar ones to ucLinux mailing-list.
> But it will be certainly appreciated if you can also share your experience
> and thoughts on ucLinux.
> 
> 1. How much is supported in terms of Cortex-M3 in U-Boot?

You could probably re-use a lot of the existing ARM infrastructre -
except for the CPU specific code, and any SoC specific drivers you
need.

> 2. Is it possible to port u-boot (including ucLinux) to a SoC with such
> limited resources? What's the minimum footprint of U-Boot across all the
> processors/architectures it supports?

You have enough flash. Small configurations of U-Boot for ARM fit in
128 kB of flash, and most of them fit in 256 kB. But you will need
more RAM. Normally U-Boot relocates itself nto RAM, and even in small
configurations you will need 512 kB or more RAM, depending on
features.

So unless you can add more RAM, much more RAM, I don't see how you
could run U-Boot on this system.

Hm... and if you had U-Boot - what would you want to use it for?
U-Boot is a boot loader, primarily intended to load and start Linux.
But your system is way too weak for Linux.

> 3. What's the best toolchain to compile U-Boot for Cortex-M3?

ELDK, of course :-) [But hey, I'm obviously biased.]

Actually any decent ARM tool chain should do.

Best regards,

Wolfgang Denk

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