[meta-xilinx] Kernel Command Line problem

[Martin Townsend]

Hi,

I now have the 3.10 Kernel booting.  I had an issue where my Kernel 
bootargs that I had setup in the U-Boot environment weren't being used 
by the Kernel.  After some debugging I found that they were being 
overwritten by the ones in the 'chosen' section of the device tree.  My 
understanding (which may be wrong) is that the bootargs passed by the 
bootloader have a higher precedence than the one in the device tree so I 
hacked the prom.c file in arch/microblaze/kernel/prom.c so it doesn't 
process 'chosen' to get things working.  The reason I want to use U-Boot 
bootargs is that we are mounting the Root Filesystem using NFS and each 
board will have a different rootpath variable in the U-Boot env, we are 
also storing the unique MAC address here too.  It's easier to program a 
unique environment rather than regenerate the device tree.

First am I right in assuming the bootloader should have higher 
precedence and if so I would appreciate if someone could look at this 
patch that I'm using as a hack and advise on the right way to do it :)

Best Regards,
Martin.

diff --git a/arch/microblaze/kernel/prom.c b/arch/microblaze/kernel/prom.c
index 0a2c68f..bff2c75 100644
--- a/arch/microblaze/kernel/prom.c
+++ b/arch/microblaze/kernel/prom.c
@@ -118,7 +118,8 @@ void __init early_init_devtree(void *params)
       * device-tree, including the platform type, initrd location and
       * size, TCE reserve, and more ...
       */
-    of_scan_flat_dt(early_init_dt_scan_chosen, cmd_line);
+    if(cmd_line[0] == '\0')
+        of_scan_flat_dt(early_init_dt_scan_chosen, cmd_line);

      /* Scan memory nodes and rebuild MEMBLOCKs */
      of_scan_flat_dt(early_init_dt_scan_root, NULL);
-- 
1.8.3.2