Hi,
I have a very basic query regarding kernel porting on different
boards. I understand that even if two boards have the very same
processor core (say MIPS 4KE), we need to port linux for them
seperately. I have heard things like it is because of certain "board
level differences", I need to provide some "board specific hooks"
because the boards may contain "different devices" and so on ....
1) Can any one please shed some light on precisely and exactly what
are differences in different boards for which we need to port linux?
2) Also, I would appreciate if you could point out code portions /
source files that need to be changed in the process of porting Linux?
TIA,
Rick
<snip>
1) Can any one please shed some light on precisely and exactly what are
differences in different boards for which we need to port linux?
The differences depends on the boards ... Mostly if they belong to the
same family the differences could be mainly in the peripherials ...
Interrupt mappings... Serial interface ... Memory sizes (if differnet
boards have different memory sizes) ... Sometimes some devices may be
moved to some other locations in the memory map (Look at memory map of
your SoC on your board).
2) Also, I would appreciate if you could point out code portions /
source files that need to be changed in the process of porting Linux?
Look in linux-2.6.20\arch\mips\mips-boards for help on porting to your
board. You can add directory specific to your board here.
I think you can start from xxx_setup.c file in the above directory.
Good luck.
Ajay.
TIA,
Rick
On Fri, 2007-02-16 at 07:46 +0530, Rick Brown wrote:
Your quoting style sucks. I fixed it by hand.
[...]
> > 1) Can any one please shed some light on precisely and exactly what are
> > differences in different boards for which we need to port linux?
> On Fri, 2007-02-16 at 09:48 +0530, Ajay Singh (ajaysi) wrote:
> The differences depends on the boards ... Mostly if they belong to the
> same family the differences could be mainly in the peripherials ...
> Interrupt mappings... Serial interface ... Memory sizes (if differnet
> boards have different memory sizes) ... Sometimes some devices may be
> moved to some other locations in the memory map (Look at memory map of
> your SoC on your board).
You may have different boot loaders (or none at all).
You also may have different storage media like FlashRAM, IDE,
network, .... for boot loader/kernel/root filesystem. They may have
different sizes and it makes a "little" difference for your requirements
in the toolchain if you have 4MB or 1GB to boot your system from.
All that kind of information can be found in a BSP (board support
package).
Bernd
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