Raj,

I found out how to debug the boot process of the PI from:

https://github.com/raspberrypi/documentation/blob/master/hardware/raspberrypi/bootmodes/README.md

by turning on the boot code debug.

sed -i -e "s/BOOT_UART=0/BOOT_UART=1/" bootcode.bin

I found out that the sdio overlay does not exist!

MESS:00:00:07.868162:0: dtdebug: Failed to open overlay file 'overlays/sdio.dtbo'
MESS:00:00:07.874093:0: Failed to load overlay 'sdio'
MESS:00:00:07.878881:0: brfs: File read: /mfs/sd/overlays/sdio.dtbo
MESS:00:00:07.891322:0: brfs: File read: /mfs/sd/cmdline.txt

So what am I missing on how to turn on the sdio on GPIO22-27? Is it not an overlay and instead a driver/other code/linux config that needs to be set?

Chuck

On 11/17/20 4:29 PM, chuck kamas via lists.yoctoproject.org wrote:

Raj,


Thanks for taking the time to respond. I thought of that too. My custom Yocto build has the line to turn on the sdio in it:

dtoverlay=sdio,poll_once=off

I have attached the entire file: config.txt.yocto

However, the Rasbian image does not have any mention of the dtoverlay for the sdio.  Curious. See config.txt attached.


Thanks for the help!

Chuck


On 11/17/20 12:08 AM, Khem Raj wrote:

On Mon, Nov 16, 2020 at 11:43 PM chuck kamas via
lists.yoctoproject.org <chuckkamas=yahoo.com@...>
wrote:

Hi all,


I have been spinning my wheels for two days trying to discover how to
enable MMC1 on a CM3. This is the one on GPIO22-27. I can boot Rasbian
on the CM3 and it inits the MMC1 and its pins just fine. I can
read/write to my SD card from it etc. However, when I build yocto it
leaves the GPIOS22-27 in gpio mode and does not set them to MMC1 mode.
I have tried changing the device tree as described here:

https://stackoverflow.com/questions/44702426/how-to-setup-an-own-device-tree-for-a-raspberrypi-in-yocto

That compiles and add the .dtbo to my build, but still the GPIOS are not
set to MMC1 mode.

cat /sys/kernel/debug/pinctrl/*gpio*/pinmux-pins
Pinmux settings per pin
Format: pin (name): mux_owner gpio_owner hog?
....

pin 22 (gpio22): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 23 (gpio23): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 24 (gpio24): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 25 (gpio25): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 26 (gpio26): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 27 (gpio27): (MUX UNCLAIMED) (GPIO UNCLAIMED)

.....

I have looked at:

https://ralimtek.com/raspberry%20pi/electronics/software/raspberry_pi_secondary_sd_card/


Any ideas of where to look next to turn on the sdio would be appreciated!

what does /boot/config.txt look like on raspbian and yocto built images

Chuck