title: Uboot hangs after "Starting kernel" message
body: <p>I compiled a linux kernel for my Toshiba AC100 and want to boot it via uboot.
  Problem: After displaying the message "Starting Kernel" nothing happens.
  The flag <code>CONFIG_DEBUG_LL</code> was set but there is still no output after this message.</p>
  
  <p>I have another precompiled kernel (but too old to use) which comes with its own dtb file and this one boots (same bootargs as the non-booting kernel).
  Observation: If I change the dbt file for this kernel it shows the same behavior as the non-booting kernel, just displaying the "Starting kernel" line.</p>
  
  <p>So I guess my problem is related to the dbt file I use for my kernel.
  Are there any methods to check if the dbt file is right for my board?
  What else could I do to get some information what the problem is?</p>
  
  <p>The entry in the <em>boot.scr</em>:</p>
  
  <pre><code>    setenv bootargs 'root=/dev/mmcblk0p7 rootfstype=ext4 earlyprintk=vga console=tty0 mem=448M@0'
      setenv bootmenu_4 "Boot Arch Linux =ext2load mmc 0:7 0x1000000 /boot/zImage; ext2load mmc 0:7 0x2000000 /boot/tegra20-paz00.dtb; bootz 0x1000000 - 0x2000000"
  </code></pre>
  
  <p>And here's the output form <em>u-boot:</em></p>
  
  <pre><code>    2255488 bytes read in 116 ms (18.5 MiB/s)
      14153 bytes read in 82 ms (168 KiB/s)
      Kernel image @ 0x1000000 [ 0x000000 - 0x226a80 ]
      ## Flattened Device Tree blob at 02000000
         Booting using the fdt blob at 0x2000000
         Loading Device Tree to 0fff9000, end 0ffff748 ... OK
  
      Starting kernel ...
  </code></pre>
  
  <p>I tried also to extract the config from the working kernel and built a new kernel with this config, but this one does not work, too (does not matter which dtb file I use).</p>
  
  <p><strong>EDIT</strong>:
  Finally I solved it by changing the kernel config from
  <code>CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA</code></p>
  
  <p>to</p>
  
  <p><code>CONFIG_TEGRA_DEBUG_UARTA</code></p>
  
  <p>After this, the kernel boots fine.</p>