2383354_en-US

[#1]

i.MX93 Nitrogen93 SMARC: UUU script hangs at FB to FBK transition after launching Initramfs

Context & Environment:
Hardware: Nitrogen93 SMARC Development Board (i.MX93)
UUU Version: 1.2.39
OS/Images: Loading the Linux kernel, .dtb and an initramfs via Fastboot to handle eMMC provisioning.
USB Configuration: FunctionFS / ConfigFS USB gadget support is explicitly enabled in our kernel and initramfs configuration.

The problem is:
The UUU script hangs indefinitely right during the transition from the Fastboot (FB) stage to the Fastboot Kernel (FBK) stage.
On the host PC terminal, UUU successfully executes the boot command and stalls:
1:9-0019B8127987>Start Cmd:FB: acmd booti ${loadaddr} ${initrd_addr} ${fdt_addr}
1:9-0019B8127987>Okay (0.001s)

On the target serial console, the kernel boots and launches the initramfs environment, but it blocks and opens an interactive shell rather than handing control over to the UUU daemon:
[ 3.087193] Run /init as init process
/bin/sh: can't access tty; job control turned off
~ # [ 3.141909] mmc2: new ultra high speed SDR104 SDIO card at address 0001

Because the console drops straight into a standard shell (~ #), the script never acts on the subsequent FBK: flashing commands.

Key Snippets of our  custom UUU Configuration
We are defining the boot arguments and initiating the boot sequence as follows:
FB: ucmd setenv bootargs "console=ttyLP0,115200 root=/dev/ram0 rw rdinit=/init mfg_mmcdev=${emmc_dev}"
FB: acmd booti ${loadaddr} ${initrd_addr} ${fdt_addr}
# Script hangs here; FBK commands below are never processed
FBK: ucmd cmdline=`cat /proc/cmdline`; ...

We are stuck at the transition between the Fastboot (FB) and Fastboot Kernel (FBK) stages in our custom UUU script.
The target drops into an interactive shell, and the script hangs. How do we proceed from this point to get the UUU daemon talking to the host?

Thanks

Re: i.MX93 Nitrogen93 SMARC: UUU script hangs at FB to FBK transition after launching Initramfs

Hello,

Please try to run from you current shell: 

\linuxrc&

If that makes FBK appear your issue is initramfs content / entrypoint

Example · nxp-imx/mfgtools Wiki · GitHub