UM0844 datasheet(33/43 Pages) STMICROELECTRONICS

33 / 43 page

UM0844

Working with customized kernels

Doc ID 16544 Rev 3

33/43

$ make spear300_defconfig

To modify the default configuration, run from the terminal the "make menuconfig" tool in the

kernel source tree root directory. Now you can change all the configuration options.

To navigate in the menu structure and change the options you need, use the arrows keys.

When all changes are done, you can save the configuration and exit. The new configuration

is saved in a hidden ".config" file. If you like, you can choose another name.

5.2

Rebuilding the kernel

After the configuration step is finished, kernel can be rebuilt with a "make" command:

$ make uImage

If you configured some components as modules, you also need a "make modules"

command afterwards.

Time required for the build process is highly variable, depending on the number of features

you choose during the configuration step and your PC speed (usually it takes some

minutes).

When the build process is completed, you can find the kernel images in the arch/arm/boot

subdirectory of the kernel tree, both as uncompressed (Image) and compressed (zImage,

uImage) kernel image.

5.3

Workflow models

The kernel binary image is always generated on the development PC. However, there are

many approaches (workflows) to make the kernel operating on the target evaluation board.

The main ones are described in following subsections.

5.3.1

Booting the kernel on-demand

If the board can be connected to the development PC through an Ethernet LAN, one

solution is to load the kernel binary image file just after reset by configuring U-Boot for

automatic file transfer by TFTP protocol.

This approach is especially useful when frequently modifying the kernel, for instance during

adaptations to a device drivers that are statically linked with kernel code.

To enable TFTP support on the development PC, you must make sure that the TFTP

daemon program /usr/sbin/in.tftpd is installed. On Fedora Core systems you can verify this

by running:

$ rpm -q tftp-server

If necessary, install the TFTP daemon program from your distribution media.

Most Linux distributions disable the TFTP service by default. To enable it, for example on

Fedora systems, edit the file /etc/xinetd.d/tftp and remove the line

disable = yes

or change it into a comment line by putting a hash character in front of it. An example of

TFTP file configuration is shown below:

UM0844 bảng dữ liệu(PDF) 33 Page - STMicroelectronics

UM0844 bảng dữ liệu(HTML) 33 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

bảng dữ liệu tải về

Link URL