"Paugam Luc" luc.paugam@thomson.net schreibt:
My U-Boot dev. Env: eldk-arm-linux-x86 v3.1.1, ARCH=arm, CPU=AT91RM9200, BOARD="custom"
I would like to know if D-Cache has to be set OFF or ON in order to boot Linux?
OFF (see http://www.arm.linux.org/developer/booting.php)
Because at first I enable the D-Cache into start.S, but the Linux kernel source codes (arch/arm/kernel/head-armv.S) require that D-Cache must be OFF by the boot loader.
Then you already knew the answer to your question.
What do U-Boot developers while booting Linux-arm from U-Boot?
Follow the guidelines from rmk, of course.
Here is my cp15 initialization, coded into start.S
Err, why don't you use the already present cpu/arm920t/start.S and cpu/arm920t/at91rm9200/lowlevel_init.S ?
/* set bits 31:30 (iA, nF) Asynchronous Clocking mode */ orr r0, r0, #0xC0000000
Don't touch the clocking mode until /after/ you have set up the PLLs and given them time to stabilize!
Cheers Anders