... exist, I created it with the following: cat /proc/cmdline > /boot/cmdline.txt My modified /boot/cmdline.txt console=ttyS1,115200 console=tty0 root=PARTUUID=d2175aeb-02 rw rootwait smsc95xx.macaddr=b8:27:eb:ff:e0:73 usb-storage.quirks=0x0bc2:0xa013:u My /proc/cmdline after booting with the above ...

... fi; if run loadimage; then if env exists root; then echo root has been defined by user; els e part uuid ${devtype} ${bootpart} uuid; setenv root PARTUUID=${uuid}; fi; run mainargs; if run loadfdt; then if run loadrd; then bootz ${loadaddr} ${rdaddr} :${filesize} ${fdtaddr}; else bootz ${loadaddr} ...

... mobility grouping on. Total pages: 129920 [ 0.000000] Kernel command line: console=ttyS0,115200 mtdparts=orion_nand:1M(u-boot),-(rootfs) root=PARTUUID=00f2f78e-a137-4081-b90d-8d8453c03e4b rw rootwait [ 0.000000] PID hash table entries: 2048 (order: 1, 8192 bytes) [ 0.000000] Dentry cache hash ...

... are ignored. I boot now from the SD. So now: [root@alarm boot]# dmesg | grep root [ 0.000000] Kernel command line: console=ttyS0,115200 root=PARTUUID=76e8d7a4-01 rw rootwait [ 3.286944] Waiting for root device PARTUUID=76e8d7a4-01... [ 5.040598] VFS: Mounted root (ext4 filesystem) on device ...

The original boot.txt is: part uuid ${devtype} ${devnum}:${bootpart} uuid setenv bootargs console=${console} root=PARTUUID=${uuid} rw rootwait if load ${devtype} ${devnum}:${bootpart} ${kernel_addr_r} /boot/zImage; then if load ${devtype} ${devnum}:${bootpart} ${fdt_addr_r} /boot/dtbs/${fdtfile}; ...

how can I achieve it?
how can I put here:
$this->bbcode_second_pass_code('', '
part uuid ${devtype} ${devnum}:${bootpart} uuid
setenv bootargs console=${console} root=PARTUUID=${uuid} rw rootwait
')
that ${uuid} is the UUID of /dev/sda1. Please, write specific code.

PartUUID vs UUID? NOT THE SAME THING. I Am Not Your Manual I do not pretend to. There is no documentation about that. The developers change the uboot and then some user asks because it broke the previous functionality. In ...

... order, mobility grouping on. Total pages: 522560 Jun 07 10:29:37 alarm kernel: Kernel command line: cros_secure console=tty0 init=/sbin/init root=PARTUUID=5c500120-17cb-6145-bd8c-dc975a4f5fd8/PARTNROFF=1 rootwait rw noinitrd Jun 07 10:29:37 alarm kernel: PID hash table entries: 4096 (order: 2, ...

... fi; if run loadimage; then if env exists root; then echo root has been defined by user; else part uuid ${devtype} ${bootpart} uuid; setenv root PARTUUID=${uuid}; fi; run mainargs; if run loadfdt; then if run loadrd; then bootz ${loadaddr} ${rdaddr}:${filesize} ${fdtaddr}; else bootz ${loadaddr} ...

... else setenv bootpart 1; fi part uuid ${devtype} ${devnum}:${bootpart} uuid setenv bootargs "console=tty0 console=${console} root=PARTUUID=${uuid} rw rootwait" if load ${devtype} ${devnum}:${bootpart} ${kernel_addr_r} /boot/zImage; then gpio set 54 echo fdt: ${fdtfile} if ...