[U-Boot] About mtest on boot

[Anatolij Gustschin]

Hi,

On Fri, 20 Jan 2012 08:07:41 -0200
Érico Porto <ericoporto2008 at gmail.com> wrote:

> Hello,
> 
> I want to stop autoboot and use mtest to check if my ram is alright, but
> 0x07FD2C00 forward freezes, and 0x00000902 also freezes, mtest, when using
> it. My ramsize is 0x08000000.
> 
> Does u-boot uses any parts of ram by itself, I mean, is there any known
> spots where I can't test because it would crash my system?

U-Boot relocates itself into RAM. You can check the address using
'bdinfo' command (look at 'relocaddr' in the output). There are
also some data structures in RAM (global data, board info, stack,
malloc area) and also exception vectors. Where it is located in
RAM depends on your architecture and board configuration options.
You can try to define DEBUG in the arch board.c file to get more
info. Board config file should define CONFIG_SYS_MEMTEST_START and
CONFIG_SYS_MEMTEST_END to prevent crashing when mtest is invoked.

HTH,
Anatolij