[U-Boot-Users] New version of AT91-Bootstrap forAT91SAM92xU-Boot/Buildroot/Linux users

Ulf Samuelsson ulf at atmel.com
Mon Mar 26 09:17:27 CEST 2007

> In message <4606F5D2.4060005 at atmel.com> you wrote:
>> Since I am using buildroot, I want everything to compile using uclibc,
>> NWFPE and a dynamic C library.
> Please correct me if I'm wrong, but we are talking about a < 4kB
> standalone NAND / dataflash bootstrap loader here, right?
> I don't think you use *any* of NWFPE or uclibc specific code in it,
> nor any "dynamic C library".
> Requiring to use "uclibc, NWFPE and a dynamic C library" for  such  a
> piece of code seems fundamentally broken to me.

The requirement is not that at91-bootstrap must use this.
The requirement is that it is *able* to be built by this.

I am using buildroot with extensions, and my requirement is that
I want to have one single package, which can as output generate

* Single Cross Compiler able to build all things below
* Standalone NAND/Dataflash bootloader
* U-Boot
* Linux Kernel
* Root File System

The Linux kernel is built using NWFPE, uclibc and dynamic C library.
Thus I need to be able to use the same toolchain for the rest to fulfil the 

Not including the C library routines memset, memcpy and div
*forces* you to use the C library, and you cant have a dynamic loaded
library in 4 kB, so it has to be static and thus it fails .

The new at91-bootstrap, with those routines can be built
* using NWFPE or softfloat - did not matter in the old version either
* static or dynamic c  library - old version HAD to have a static library
* cross-compiler compiled for uclibc, glibc or newlib

The NWFPE issue is with U-Boot.
U-Boot cannot compile, since it has -msoftfloat hard-wired
and this is really not neccessary. By removing the -msoftfloat
you can compile using a NWFPE enabled compiler.

Due to dataflash sector boundaries, the natural size for U-Boot + Loader is
256 kB or less. I did not check the effect on U-Boot code size
due to NWFPE enabled, but there should be little or none FPU code
in U-Boot.

It is more important to me to have a single toolchain, and it will be
Linux needs which determines the toolchain.

> Best regards,
> Wolfgang Denk
> -- 

Best Regards
Ulf Samuelsson                ulf at atmel.com
Atmel Nordic AB
Mail:  Box 2033, 174 02 Sundbyberg, Sweden
Visit:  Kavallerivägen 24, 174 58 Sundbyberg, Sweden
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