Hi,
I have U-Boot and a BeagleBoard. I have an MMC with three partitions,-VFAT (with the ift and MLO files), SquashFS and Ext3 inserted into the board.
If I write in U-Boot console (from minicom terminal):
setenv bootargs
bootargs gets set to nothing. When I write:
printenv bootargs
U-Boot replies
## Error: "bootargs" not defined
as it should be. When I write:
printenv
U-Boot shows on screen a bunch of variable and among them is bootargs defined like this:
bootargs console=ttyS2,115200n8 noinitrd root=/dev/mmcblk0p1 rootfstype=ext3 rw rootdely=3 nohz=off
Apparently even if bootargs is not set there is something in it by default. Now if I boot the kernel it shows a message:
Kernel command line: root=/dev/mmcblk0p2 rootwait console=ttyS2,115200
It seems if bootargs is empty (or whatever value it is after setenv bootargs) the U-Boot loader searches all partitions of the MMC, locates one it can mount a file system from (p2 in this case where SquashFS resides) and proceeds to pass it to kernel (and the kernel uses it further in the boot process).
If, on the other hand, there is some value in bootargs, this value is passed onto the kernel which in turn uses further in the boot process. I've tried to trace this in code but could not make any of it.
Is this how it works?
Thanks
