IMX8MQ EVK board - SD card is not mounted

[chaitanyaarur]

Hi, 

While working on i.MX 8M QUAD EVK board bring up, eMMC mode boot up is successfully. SD card mode boot up is also successful. But, our application required to access SD card as a media storage device.

In eMMC boot up mode, SD card is not detected as storage device.

From the analysis of dmesg logs, it is understood that SD card is detected. But, SD card is not mounted in /data/media or /mnt or /storage or /sdcard folders. please find log snippet below.

Line 628: [ 12.275079] sdcardfs version 2.0
Line 629: [ 12.278619] sdcardfs: dev_name -> /data/media
Line 630: [ 12.284936] sdcardfs: options -> fsuid=1023,fsgid=1023,multiuser,derive_gid,default_normal,mask=6,userid=0,gid=1015
Line 631: [ 12.300862] sdcardfs: mnt -> ffff800052ee4aa0
Line 632: [ 12.306297] sdcardfs: mounted on top of /data/media type ext4
Line 634: [ 12.330585] sdcardfs : options - debug:1
Line 635: [ 12.334936] sdcardfs : options - gid:9997
Line 636: [ 12.339348] sdcardfs : options - mask:23
Line 638: [ 12.353528] sdcardfs : options - debug:1
Line 639: [ 12.357999] sdcardfs : options - gid:9997
Line 640: [ 12.362183] sdcardfs : options - mask:7

Also, few errors are observed in logcat when SD card is mounted and unmounted. please find the log snippet below.

04-06 19:48:26.848 3006 3006 E /vendor/bin/hw/android.hardware.health@2.0-service.imx: /sys/block/mmcblk0/stat: ReadFileToString failed.
04-06 19:48:26.846 3006 3006 W health@2.0-serv: type=1400 audit(0.0:7594): avc: denied { read } for name="stat" dev="sysfs" ino=21584 scontext=u:r:hal_health_default:s0 tcontext=u:object_r:sysfs:s0 tclass=file permissive=0
04-06 19:48:31.050 3006 3006 W health@2.0-serv: type=1400 audit(0.0:7595): avc: denied { read } for name="stat" dev="sysfs" ino=21584 scontext=u:r:hal_health_default:s0 tcontext=u:object_r:sysfs:s0 tclass=file permissive=0
04-06 19:48:31.054 3006 3006 E /vendor/bin/hw/android.hardware.health@2.0-service.imx: /sys/block/mmcblk0/stat: ReadFileToString failed.
04-06 19:48:31.054 3029 3066 E storaged: getDiskStats failed with result NOT_SUPPORTED and size 0

Why SD card is not mounted properly in file system(even though it is identified)?.

Please check and provide your feedback. Complete logs are attached for reference.

[chaitanyaarur]

Hi, 

Thank you very much for the reply

sect.4.7.6 Running Linux OS from MMC/SD is about SD card boot up, it is already successful for us.

In eMMC boot up mode, SD card is connected with media files. SD card is not detected as a external storage device.

Please suggest.

Regards,

Chaitanya.A 

[chaitanyaarur · Accepted solution]

SD card is detected after editing fstab.nxp file inside /vendor/etc

mount path needs to be added in fstab.nxp for mounting secondary storage device.

/dev/block/platform/soc@0/*.soc/*.mmc /mnt ext4 defaults voldmanaged=sdcard1:auto

SD card is found in /mnt/media_rw/

[divyeshmarne0]

hi @chaitanyaarur and @igorpadykov ,

If we are adding /mnt as a mounting path, then sdcard is detecting under /mnt/media_rw/ path ?

Please suggest asap ?

Thanks

Divyesh.

[igorpadykov]

Hi Chaitanya

reason may be in sd card numbering as described in sect.4.7.6 Running Linux OS from MMC/SD

Table 54. Linux uSDHC relationships  i.MX Linux User’s Guide​

Best regards
igor