Boundary Devices Nitrogen series Podręcznik użytkownika - Strona 10

Przeglądaj online lub pobierz pdf Podręcznik użytkownika dla Jednostka sterująca Boundary Devices Nitrogen series. Boundary Devices Nitrogen series 15 stron.

Drukuj stronę

5.2 Das U-Boot

To boot without a RAM disk, we'll just skip loading it and only supply a single argument to the

bootm command. In this case, the ﬁlesystem root should be speciﬁed on the kernel command-line

(bootargs U-Boot variable.

U-Boot> set bootcmd 'mmcinit &&

fatload mmc 0 92000000 uImage &&

bootm 92000000'

U-Boot> saveenv

Whenever you're booting Linux, these are some key kernel command-line variables you may want

to set:

video= - Speciﬁes the video resolution and output form. See section 5.8 for details.

console=ttymxc0,115200 - Sets /dev/console to the ﬁrst UART, the same as U-Boot uses

If you're booting over NFS, you'll need to add these clauses:

ip=dhcp

rootwait

root=/dev/nfs

nfsroot=10.0.0.1:/path/to/rootfs

5.2.2

Using U-Boot with Windows CE

Using U-Boot to load Windows CE is simpler, since it uses neither bootargs nor a RAM disk and

currently has compiled-in display settings.

Consequently, the command line is typically this to load CE from SD card:

U-Boot> setenv bootcmd 'mmcinit &&

fatload mmc 0 90200000 NK6-nitrogen e.nb0

&& go 90200000'

U-Boot> saveenv

If you want to load CE over TFTP, a suitable command-line might be this:

U-Boot> set bootcmd 'dhcp 90200000 192.168.0.251:NK6-nitrogen e.nb0

&& go 90200000'

U-Boot> saveenv

Note that each of these is using the go command and not bootm.

March 10, 2011

This tells the kernel to perform a DHCP to get an IP

address. You'll also need kernel support for DHCP

to use this. Check with the Linux command zcat

/proc/config.gz | grep DHCP.

This clause tells the kernel not to expect that a RAM

disk is immediately available.

This clause tells the kernel that the root device is

NFS.

This clause tells the NFS device driver what server

and path to use as the root ﬁlesystem.

Revision 1.5