I have a new question that maybe somebody can answer, please.
I am changing the Linux kernel:
I change board-overo.c and omap2_mcspi.c (in order to send a string through
SPI between a Gumstix Overo Palo 43
-with OMAP 3530 in it, acting as a master- to a TI 1278 slave).
I put the new Linux kernel (i.e.: uImage) on a SD card on the PALO43.
The PALO 43 boots from a NAND then starts from the SD card my Linux
(modified for SPI).
The modified Linux crashes, per console display of a log file of boot shown
By disabling all my changes and enabling them one by one, my Linux compiles
well but crashes when SD runs it,
outb(0, (int *) 0x480021C8); that declares OMAP3530 pins at address 4800
21C8 as SPI pins mcspi1_clk and mcspi1_simo
outb(0, int*)0x480021CC); that declares mcspi1_somi and mcspi1_cs0
per TI doc.
I declared SPI pins two years ago, in an environment different than Gumstix.
(thanks to Charles Ash for answering my previous related question suspecting
rootfs, but my question now evolved)
how do I replace outb(value, port) in a Gumstix environment so that PALO43
boots from NAND, starts the Linux in the SD card,
and the Linux on the SD card doesn't crash?
Ion A. Beza.
From: Dave Hylands <dhylands@gm...> - 2010-01-28 00:56:14
> outb(0, (int *) 0x480021C8); that declares OMAP3530 pins at address 4800
> 21C8 as SPI pins mcspi1_clk and mcspi1_simo
0x480021C8 is the physical address. Once the MMU is turned on, all
accesses must be done using virtual addresses.
I believe that you can use the IO_ADDRESS macro and pass in the
physical address to get the virtual address, but I haven't actually
done this myself on the omap platform/.
Shuswap, BC, Canada