Am 2005-02-12 14:02 -0700 schrieb Grant Likely:
Please make sure that you include the mailing list when you reply to me.
Oh sorry! I messed up List-Reply and simple Reply again in mutt. Normally I only reply to the mailing list itself :/
You think? If possible; I would get some hard numbers on your boot sequence and find out for sure. You could use a serial protocol analyser to attach timestamps to the boot logs. Make sure you're optimizing the right things.
Yes, its time now to measure all steps of the boot process exactly. The serial analyzer idea is quite good. Why isn't it mine :)
arch/arm/boot/compressed/head.S. You will see a branch to cache_on at line 287 before decompress_kernel at line 310. (2.6.10) According to the comment on line 422 the page tables are setup for wherever the compressed image is; including if it is in FLASH.
Yes I see. But I don't understand the assembler code really yet. Do you mean "add r0, r3, r2, lsl #2" by line 422, where addresses above 0x10040000 (there my kernel lives) are added to cacheable area?
To u-boot prompt or to linux prompt?
To linux prompt. I heard from a sony demo where an ARM9 based system starts video encoding one second after power up. I asked in linux-arm-kernel last year and some guy mentioned that. So I thought I could reach the prompt also in one second :/
safe to assume that you've got a 'boot loader' flash device with a small first (~16k)?
What do you mean by that?
I mean that some flash devices have some small sectors at the beginning specifically to hold the boot loader. If you were trying to save space I wondered if you were trying to fit into a small sector. This is often done when FLASH space is at an extreme premium.
No I have intel 28F128K3 sync burst Flash which contains even sized 128kB sectors only.
Linux can spew a lot of log messages; I suspect your time difference would be more bounded by the baud rate of the port rather than the serial device driver itself. U-boot on the other had is quite a bit
T thought also and measured and my result is the same.
Can you bump up your baud rate?
It is at 115200 now, I could bump it but I don't think it will to significant time saving due to the above reasons...
Konsti