[U-Boot-Users] Using U-BOOT in CSB272 board

[Tolunay Orkun]

Lonsn,

I am the maintainer of CSB272 port of U-Boot. I've done the port 
based on technical info of the board which is not very reliable. 
Unfortunately, Cogent generally is not very responsive to emails 
regarding the ambiguous/outdated technical information about their 
boards.

Some information is extracted by using BDI2000 after uMon 
intitialized the hardware. Some information is based on datasheet of 
the parts.

This is actually a discontinued board. In our application here, we do 
not use the Epson controller.  We have switched to using CSB472 
now which is smaller and does not have the parts we do not use.

On 8 Sep 2004 at 22:23, Lonsn wrote:

> then bootm, kernel panic at init EPSON1356 Display Controller, so I 
> reset U-BOOT, I download kernel again

To me it sounds like your Epson1356 driver issue in Linux kernel. 
You should debug the driver to find out what exactly within the driver 
is causing the panic.

Check the assumptions made by the driver. The particular driver 
may be assuming that bootloader is doing a particular initialization 
however a well written driver should not assume these and re-
inititialize the hardware suitably. It could also be a race condition or 
an uninitialized variable.

> When I disabled framebuffer support in kernel, then every time booting 
> linux is ok.
> I used another bootloader uMon and enabled framebuffer support in 
> kernel,every time booting linux is ok.
> I have changed bd_t struct in kernel, then it is the same as in U-BOOT, 
> undefined CFG_CLK_Mhz,
> I compiled U-BOOT with csb272_config.

Obviously bd_t structure should match between kernel and U-Boot. 
You can comment bd_t definition and include "ppcboot.h" instead 
for U-Boot compatible version.

> Should I pay attention to SDRAM init sequence in U-BOOT as Wolfgang has 
> said many times?

As far as I know SDRAM initialization for CSB272 is correct. The 
information supplied by Cogent in the tech. documentation is for 
32MB SDRAM (older) version of the board but your and my board 
are 64MB.

> *** Warning - bad CRC, using default environment

Why didn't you do a "saveenv" so default environment would be 
written. You've should set ethaddr variable in environment for 
networking to work correctly.

Best regards,
Tolunay