Good point, will try to implement that, but don't have access to UART in the current setup.put uart on the cm4
I figured out something else.
After loading mass-storage-gadget64 it sometimes takes 15s until it shows as MSD, sometimes it takes like 40s but it is also possible that it takes like 160s. Is there any reason for that? Maybe some kind of internal eMMC cleanup?
(I flashed this CM4 many times without running it for long..)
Sample dmesg from Pi4 with 160s between rpiboot and MSD
Code:
[66131.614988] usb 1-1.4: new high-speed USB device number 9 using xhci_hcd[66131.703470] usb 1-1.4: New USB device found, idVendor=0a5c, idProduct=2711, bcdDevice= 0.00[66131.703497] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=4[66131.703509] usb 1-1.4: Product: BCM2711 Boot[66131.703520] usb 1-1.4: Manufacturer: Broadcom[66131.703529] usb 1-1.4: SerialNumber: c7b78f60[66136.153403] usb 1-1.4: USB disconnect, device number 9[66296.448769] usb 1-1.4: new high-speed USB device number 10 using xhci_hcd[66297.149380] usb 1-1.4: device descriptor read/64, error -71[66297.345502] usb 1-1.4: New USB device found, idVendor=0a5c, idProduct=0104, bcdDevice= 1.00[66297.345535] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3[66297.345550] usb 1-1.4: Product: Raspberry Pi multi-function USB device[66297.345563] usb 1-1.4: Manufacturer: Raspberry Pi[66297.345573] usb 1-1.4: SerialNumber: 10000000c7b78f60[66297.351203] usb-storage 1-1.4:1.0: USB Mass Storage device detected[66297.351899] scsi host1: usb-storage 1-1.4:1.0[66297.359199] cdc_acm 1-1.4:1.1: ttyACM0: USB ACM device[66298.361132] scsi 1:0:0:0: Direct-Access mmcblk0 PQ: 0 ANSI: 2[66298.361543] sd 1:0:0:0: Attached scsi generic sg1 type 0[66298.361641] sd 1:0:0:0: Power-on or device reset occurred[66298.366021] sd 1:0:0:0: [sdb] 30535680 512-byte logical blocks: (15.6 GB/14.6 GiB)[66298.496744] sd 1:0:0:0: [sdb] Write Protect is off[66298.496762] sd 1:0:0:0: [sdb] Mode Sense: 0f 00 00 00[66298.628688] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUAStatistics: Posted by batwing — Thu Nov 27, 2025 9:04 am