ERC32 BSP (a bit further this time)

Teng Chee Wan Philip tcheewan at ntu.edu.sg
Tue May 6 09:49:14 UTC 2008


By right, it is better to put the "specific HW setup" code in the
bootloader, rather than the start.S.  The start.S is shared among ERC32
and LEON.

Do you happen to clear the memory before loading the image into the RAM?
I am not sure if that is a problem.  
Please also check the linkcmds file. You might need to change the RAM
size.  If I understand correctly, the default memory size for the ERC32
BSP is 4 Meg and you only have 2 Meg.  So, the compiler may have set the
workspace to beyond 2 Meg.

Hope that helps.  Otherwise, we can try looking elsewhere for the
problem.

Regards,
Philip

-----Original Message-----
From: Neil Mayes [mailto:N.Mayes at sstl.co.uk] 
Sent: Tuesday, May 06, 2008 5:23 PM
To: Teng Chee Wan Philip
Cc: rtems-users at rtems.org
Subject: RE: ERC32 BSP (a bit further this time)

Hi Philip,

> A.  How do you know you are not returning from 
> rtems_initialize_executive_early()?
I have a GPIO driving an LED and on return from boot_card I am setting
the LED high. I added early returns from boot_card and can see I never
return from rtems_initialize_executive_early. Now I can see I never
return from _CPU_Initialize. If the LED does not light I have not
returned.

> B.  You mentioned that you have modified start.S (presumably 
> from 
> "\rtems-4.8\rtems-4.8.0\c\src\lib\libbsp\sparc\shared\start.S"
>  ).  What are the "specific HW setup" that you did in start.S?
OK, I am setting my HW memory config (2Mbyte SRAM (1Mbyte per memcs), 2
memory chip selects used, parity disabled), wait states set to 0 ws read
and 0 ws write, for 10 Mhz sysclk, disabling the watchdog timer and
setting UARTs to use the WDCLK @ 38K4 8 2 N. I am copying the same CPU
init code as the mkprom so clearing FPU regs, all windows etc.

Regards,
Neil




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