RE: [uCsimm] LCD Framebuffer

From: OEM industrialisation (industrialisation@oem-terminals.fr)
Date: Tue Apr 18 2000 - 12:03:03 EDT


Hi Carl,

I think you should have a look at the ucsimm-head.s,
where the LCD controller is initialized at the beginning of Linux.
This file is read before starting the kernel and its job is to initialize
the material.

It is situated in the directory
/linux/arch/m68knommu/platform/68EZ328/

To fill right the registers, you can have a look at Motorola's.
The 68EZ328 user's manual is quite complete.

In your applications, you can initialize an unsigned char pointer
on LSSA and you will directly write in the LCD frame buffer.

Note that the pixels are not in the order of the unsigned char
I use a graphic screen with binary pixels(on/off (no grey levels) )
with a four bits interface, when my pixels are disposed like that

[ 0 1 2 3 4 5 6 7 ]

the values in the unsigned char, attached to the different pixels, are

[ 16 32 64 128 1 2 4 8 ]

For example, in 320*240 mode you've got 40 colummns by 240 lines,
so it's easily programmable with the pointer.

If you want to go to the LCD at the boot of Linux
(i think it's impossible with the bootloader), you must build your own console
and register it in config.c (directory similar to ucsimm-head.s).
At the end of this file you will find a call to register_console(console_print_68328).
It's where printk register its console on the serial port.
Replace console_print_68328(const char *b) by your console (witch display a char at your LCD)
and i think it will run well (i'have already tried it).

Trying to help you,

Freddy

> -----Message d'origine-----
> De: Carl W. Price [SMTP:carl_price@agilent.com]
> Date: lundi 17 avril 2000 23:10
> : ucsimm
> Objet: [uCsimm] LCD Framebuffer
>
> Hi all,
>
> Well, I am starting to get things going, and want to
> attach an LCD panel to the board. How do I get info
> to go to the LCD on boot? Are there any example
> programs, or HOWTO on the frame buffer.
>
> Finally, is there an archive of this list that
> I can search before asking.
>
> --Carl
> carl_price@agilent.com
> This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/

This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/



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