On 9/20/18 3:57 PM, Michael Mrozek wrote:
Am Donnerstag, den 20.09.2018, 15:45 +0200 schrieb H. Nikolaus Schaller:
Hi,
Or: Can we change some EMIF values to raise stability (maybe at the cost of tiny bit performance?
As far as I remember, Tony did send some EMIF setup patch that is in notaz and letux uboot now, but noted that it might be reasonable to change some more parameters. Unfortunately I do not really understand more about them than you... So I have never played with them.
I thought EMIF is in the MLO, not in U-boot...? Or is the MLO combined with U-Boot on the Pyra?
I'm confused :)
Well, I'm perfectly fine doing trial and error with the values.
The datasheet usually has minimum and maximum listed, so I should be able to safely change them.
I'd change one value at a time between max and min to see if it improves things (or worsens them).
Also, simply comparing the values to the datasheet might help as well.
https://dev.pyra-handheld.com/notaz/pyra-u-boot/commit/4063458c6290b4e15df9d...
That has some explanation about the timings.
To compile I use make -j6 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- distclean make -j6 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- pandora_pyra_lc15_defconfig make -j6 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-
for the 4gb version use pandora_pyra_lc15_4gb_defconfig
To install to sd (for pyraos at least, letux uses a different method, and im not sure if copying a new MLO file on top of the old one will actually work there. for letux you need to use the letux uboot anyway)
dd if="MLO" of=${DISK} count=1 seek=1 bs=128k dd if="u-boot.img" of=${DISK} count=2 seek=1 bs=384k
where ${DISK} is the sd card device (just /dev/sdh , or /dev/mmcblk0 , not the partitions)