[U-Boot-Users] SED13806 and MPC866
Hi,
First i have to say "i am new in embedded Linux". I am very interested in the new 866 of Motorola. For a graphical output the EPSON SED13806 is planned. I've found in the archive that this chip is supported from U-Boot ;-) !! My question is, how to setup and to tell the kernel that the EPSON is its graphical output.
The start address in SED13806 is defined by my board with its CSx base address, i think. Is there more to tell as its start address ?
How i setup my kernel that a SED13806 exists or has my device driver to do this ??
If you know more useful things about the SED-chip, please let me know.
Thanks a lot
Marco
Marco Schramel Tel. +49(0)9929/ 301-332 R&D Fax +49(0)9929/ 301-112 BARTEC Schulstraße 30, 94239 Gotteszell,GERMANY Marco.Schramel@go.bartec.de
In message MFEGIPJEFHIKHGDLDACIIEOHCAAA.marco.schramel@go.bartec.de you wrote:
First i have to say "i am new in embedded Linux". I am very interested in the new 866 of Motorola. For a graphical output the EPSON SED13806 is planned. I've found in the archive that this chip is supported from U-Boot ;-) !!
:-)
My question is, how to setup and to tell the kernel that the EPSON is its graphical output.
The start address in SED13806 is defined by my board with its CSx base address, i think. Is there more to tell as its start address ?
How i setup my kernel that a SED13806 exists or has my device driver to do this ??
You always write "kernel". Do you mean U-Boot, or are you talking about Linux?
If you know more useful things about the SED-chip, please let me know.
You can find out a lot by grepping and reading the sources :-)
See for example "include/configs/RPXClassic.h" etc. ...
Best regards,
Wolfgang Denk
Hi,
Thanks for your reply.
Does the Linux kernel not use the u-boot functions like a bios ? Sorry for that dummy newbie question.
I tell you my level of awarness. - First i have to fit the u-boot for my board - then i arrange my Linux kernel for my board - i load my Linux down - my Linux works with functions of u-boot and therefore my Linux kernel have to know which interfaces exists
Is my thinking correct?
Thanks in advance
Marco Schramel
----------------------------------------------- Marco Schramel Tel. +49(0)9929/ 301-332 R&D Fax +49(0)9929/ 301-112 BARTEC Schulstraße 30, 94239 Gotteszell,GERMANY Marco.Schramel@go.bartec.de
In message MFEGIPJEFHIKHGDLDACIKEOICAAA.marco.schramel@go.bartec.de you wrote:
Thanks for your reply.
Does the Linux kernel not use the u-boot functions like a bios ? Sorry for that dummy newbie question.
Yes, it does. Exactly the same way. The coincidence is in NOT using any such stuff.
Linux does not use any BIOS functions, and Linux does NOT use any U-Boot code. Once Linux starts, the U-Boot image is gone (as Linux will claim all RAM thus deleting any U-Boot code that's there).
I tell you my level of awarness.
- First i have to fit the u-boot for my board
- then i arrange my Linux kernel for my board
- i load my Linux down
Rigth so far.
- my Linux works with functions of u-boot and therefore my Linux kernel
have to know which interfaces exists
Wrong. U-Boot performs certail initialization of the hardware (like setting up the memory controller), and when U-Boot passes control to Linux, it gives it a few parameters (like memory size, clock frequencies, etc.). The U-Boot is gone forever, and Linux is running. Linux cannot use any U-Boot code, and does not need to.
Best regards,
Wolfgang Denk
Thanks,
this is clear now. Such devices like my EPSON controller are a not kernel specificly. Will it be used like a normal device with a device driver ??? My kernel config has no option for a EPSON graphic controller, i think. Where do the embedded Linux store the parameters which was given by u-boot?
Thanks a lot
Marco
Dear Marco,
in message MFEGIPJEFHIKHGDLDACIGEOJCAAA.marco.schramel@go.bartec.de you wrote:
Such devices like my EPSON controller are a not kernel specificly. Will it be used like a normal device with a device driver ???
This depends on the implementation. Often you will find some device driver provided by the chip manufacturer (or some other third parties). And often this driver will provide a standard framebuffer interface.
My kernel config has no option for a EPSON graphic controller, i think.
It might have one after adding the driver to your kernel source tree :-)
Where do the embedded Linux store the parameters which was given by u-boot?
Parameters are passed in registers plus some data structure in RAM. How and where Linux stores this information depends on a couple of things, like processor architecture and kernel version.
Why do you ask?
[Maybe we should move this discussion into a Linux group?]
Best regards,
Wolfgang Denk
participants (2)
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Marco Schramel -
Wolfgang Denk