Hi,
I followed the instructions in this forum thread - viewtopic.php?t=302634 to add a sd card to the CM4 using the GPIO pins 22-27 with a custom DTS overlay.
The dts file looks likeI compile the custom DTS overlay from Lauszus after writing the sd0-overlay.dts file by running
This sets the GPIO pin 22-27 to SD0 alt and set the pull-ups. I have appended the following line to the bottom of /boot/config.txt or /firmware/boot/config.txt
I am using a CM4 module with eMMC and WiFi.
On bullseye (OS lite, 64 bit, flashed 14th May 2024) the overlay works, I can mount and write files to the SD card.
On bookworm (OS lite, 64 bit, flashed Feb 2025) I take the same steps, the SD card can be seen by the cm4 but the partitions cannot. I get these dmesg errors whenever I try to mount and it doesn't matter how I format the card (on other computers) the result is the sameIt sounds like other users are getting a similar overlay to work - viewtopic.php?t=381108
I followed the instructions in this forum thread - viewtopic.php?t=302634 to add a sd card to the CM4 using the GPIO pins 22-27 with a custom DTS overlay.
The dts file looks like
Code:
/* * Device tree overlay for enabling SD0 using the sdhost interface on GPIO 22-27 by Kristian Sloth Lauszus. *//dts-v1/;/plugin/;/{ compatible = "brcm,bcm2711"; fragment@0 { target = <&sdhost>; frag0: __overlay__ { pinctrl-names = "default"; pinctrl-0 = <&sdhost_pins>; bus-width = <4>; brcm,overclock-50 = <0>; brcm,pio-limit = <1>; status = "okay"; }; }; fragment@1 { target = <&gpio>; __overlay__ { sdhost_pins: sdhost_pins { brcm,pins = <22 23 24 25 26 27>; brcm,function = <4 4 4 4 4 4>; /* ALT0: SD0 */ brcm,pull = <0 2 2 2 2 2>; /* pull up all except clk */ }; }; }; __overrides__ { overclock_50 = <&frag0>,"brcm,overclock-50:0"; force_pio = <&frag0>,"brcm,force-pio?"; pio_limit = <&frag0>,"brcm,pio-limit:0"; debug = <&frag0>,"brcm,debug?"; };};Code:
sudo dtc -@ -I dts -O dtb -o /boot/overlays/sd0.dtbo sd0-overlay.dtsCode:
dtoverlay=sd0On bullseye (OS lite, 64 bit, flashed 14th May 2024) the overlay works, I can mount and write files to the SD card.
On bookworm (OS lite, 64 bit, flashed Feb 2025) I take the same steps, the SD card can be seen by the cm4 but the partitions cannot. I get these dmesg errors whenever I try to mount and it doesn't matter how I format the card (on other computers) the result is the same
Code:
pi@REFLEX0004:~ $ dmesg | grep mmc[ 1.869740] mmc-bcm2835 fe300000.mmcnr: mmc_debug:0 mmc_debug2:0[ 1.869755] mmc-bcm2835 fe300000.mmcnr: DMA channel allocated[ 1.948033] mmc2: sdhost-bcm2835 loaded - DMA enabled (>1)[ 2.291730] mmc1: new high speed SDIO card at address 0001[ 2.318069] mmc0: SDHCI controller on fe340000.mmc [fe340000.mmc] using ADMA[ 2.428781] mmc2: host does not support reading read-only switch, assuming write-enable[ 2.443958] mmc2: Host Software Queue enabled[ 2.452015] mmc2: new high speed SDHC card at address aaaa[ 2.510486] mmc0: new DDR MMC card at address 0001[ 2.513981] mmcblk2: mmc2:aaaa SC16G 14.8 GiB[ 2.523707] mmcblk0: mmc0:0001 8GTF4R 7.28 GiB[ 2.534829] mmcblk2: p1[ 2.536821] mmcblk0: p1 p2[ 2.539380] mmcblk2: mmc2:aaaa SC16G 14.8 GiB (quirks 0x00004000)[ 2.545289] mmcblk0: mmc0:0001 8GTF4R 7.28 GiB[ 3.526138] mmcblk0boot0: mmc0:0001 8GTF4R 4.00 MiB[ 3.533154] mmcblk0boot1: mmc0:0001 8GTF4R 4.00 MiB[ 3.539314] mmcblk0rpmb: mmc0:0001 8GTF4R 512 KiB, chardev (243:0)[ 7.864347] systemd[1]: Unnecessary job was removed for dev-mmcblk0p1.device - /dev/mmcblk0p1.[ 49.583980] /dev/mmcblk2p1/: Can't lookup blockdev[ 56.040936] F2FS-fs (mmcblk2p1): Magic Mismatch, valid(0xf2f52010) - read(0xa9890)[ 56.040962] F2FS-fs (mmcblk2p1): Can't find valid F2FS filesystem in 1th superblock[ 56.041548] F2FS-fs (mmcblk2p1): Magic Mismatch, valid(0xf2f52010) - read(0x80000)[ 56.041560] F2FS-fs (mmcblk2p1): Can't find valid F2FS filesystem in 2th superblockStatistics: Posted by tennisparty — Fri Feb 21, 2025 8:53 pm — Replies 0 — Views 1