[U-Boot] [RFC PATCH 1/3] add file with a default boot environment based heavily on Stephen Warrens recent tegra work.

[Stephen Warren]

On 02/19/2014 11:44 AM, Dan Murphy wrote:
> On 02/17/2014 11:56 AM, Dennis Gilmore wrote:
>> Signed-off-by: Dennis Gilmore <dennis at ausil.us>

>> diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h

>> +#ifdef CONFIG_CMD_USB
>> +#define BOOTCMD_INIT_USB "run usb_init; "
>> +#define BOOTCMDS_USB \
>> +	"usb_init=" \
>> +		"if ${usb_need_init}; then " \
>> +			"set usb_need_init false; " \
>> +			"usb start 0; " \
>> +		"fi\0" \
>> +	\
>> +	"usb_boot=" \
>> +		"setenv devtype usb; " \
>> +		BOOTCMD_INIT_USB \
>> +		"if usb dev ${devnum}; then " \
> 
> This may have already been highlighted but I don't see where the kernel command line arguments can be set.
> If you have the file system on the USB stick won't you need to direct the root to the stick?

They would be set in boot.scr or extlinux.cfg on the disk that the
system boots from; the kernel cmdline is part of the OS that's installed
there, not part of U-Boot. This is why these boot scripts load a
script/config-file from the disk which in turn defines which
kernel/DTB/cmdline to use, rather than directly loading a kernel and
DTB. This approach should even be suitable for booting a non-Linux-OS,
with suitable commands in boot.scr.