Rockchip Board Hangs After "Starting kernel ...": No Kernel Output

Symptoms

Last serial line is "Starting kernel ..."
Board may or may not actually be running (check network / LEDs)

Common causes

Wrong console= (UART number or baud rate, typically ttyS2 at 1500000 on newer SoCs)
DTB not matching the kernel (vendor DTB with mainline kernel or vice versa)
Kernel Image corrupted or loaded over the DTB/initrd in memory
Missing BL31 (TF-A) causing early SMC/PSCI failures

How to fix it

Turn on early console

append ... console=ttyS2,1500000 earlycon=uart8250,mmio32,0xfeb50000 ignore_loglevel

Use the DTB from the same kernel tree
Rebuild dtbs together with the Image and point extlinux.conf at that DTB.
Check load addresses
Make sure kernel_addr_r, fdt_addr_r and ramdisk_addr_r in U-Boot do not overlap for your Image size.
```
printenv kernel_addr_r fdt_addr_r ramdisk_addr_r
```

Go deeper

FAQ

What does "Starting kernel ..." mean?

U-Boot handed over to Linux and the serial console went silent. Either the kernel is printing to a different console, or it crashed very early because of a DTB or memory mismatch.

What causes "Starting kernel ..."?

Wrong console= (UART number or baud rate, typically ttyS2 at 1500000 on newer SoCs); DTB not matching the kernel (vendor DTB with mainline kernel or vice versa); Kernel Image corrupted or loaded over the DTB/initrd in memory; Missing BL31 (TF-A) causing early SMC/PSCI failures.

How do I fix "Starting kernel ..."?

1. Turn on early console 2. Use the DTB from the same kernel tree: Rebuild dtbs together with the Image and point extlinux.conf at that DTB. 3. Check load addresses: Make sure kernel_addr_r, fdt_addr_r and ramdisk_addr_r in U-Boot do not overlap for your Image size.