[U-Boot-Users] [ANNOUNCE] u-boot-ptx-20030213-1

Geir Thomassen chaos at in.fer.no
Thu Feb 13 21:42:51 CET 2003

Robert Schwebel wrote:
> Comments are welcome...  

in cpu/xscale/start.S you do:

/* test if we run from flash or RAM - RAM/BDI: don't set cpuspeed   */
/* FIXME: is the criterium used here only valid for PXA25X?         */
    mov     r0, pc
    and     r0, r0, #0xF0000000 /* RAM is at 0xa0000000-0xafffffff */
    subs    r0, r0, #0xa0000000
    beq     setspeed_done

    mov     r0, #2
    mcr     p14, 0, r0, c6, c0, 0

Why? I can trace trough the CPU speed setting code without any trouble 
with a BDI, and I don't understand why there should be any problems 
doing so. Disabeling the CPU speed setting code without skipping the 
SDRAM init code at the same time might actually get you into other 
problems since the refresh periode of the SDRAM might be too long. 
Jumping over the SDRAM init is a very good idea, since the code is 
running from the SDRAM that the code is initializing. One important step 
of the init sequence is to disable the SDRAM.


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