mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-03 09:59:44 +00:00
9c2d4057e1
Add example command how to compile U-Boot and add new documentation section describing how to enable early debug UART and verbose log output for N900. Signed-off-by: Pali Rohár <pali@kernel.org>
250 lines
9.2 KiB
ReStructuredText
250 lines
9.2 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0+
|
|
|
|
Nokia RX-51 aka N900
|
|
====================
|
|
|
|
The ``nokia_rx51_defconfig`` configuration file results in a ``u-boot.bin``
|
|
which can be chainloaded by the Nokia second stage bootloader (NOLO) in QEMU or
|
|
on a real N900. It does very little hardware configuration because NOLO has
|
|
already configured the board. It is only needed to enable the internal eMMC
|
|
memory via the twl4030 regulator which is not enabled by NOLO.
|
|
|
|
.. code-block:: bash
|
|
|
|
make CROSS_COMPILE=arm-linux-gnueabi- nokia_rx51_defconfig u-boot.bin
|
|
|
|
NOLO is expecting a kernel image and will treat any image it finds in
|
|
OneNAND as such. This u-boot is intended to be flashed to the N900 like
|
|
a kernel. In order to transparently boot the original kernel, it will be
|
|
appended to ``u-boot.bin`` at 0x40000. NOLO will load the entire image into
|
|
(random) memory and execute U-Boot, which saves hardware revision, boot reason
|
|
and boot mode ATAGs set by NOLO. Then the bootscripts will attempt to load
|
|
``uImage``, ``zImage`` or ``boot.scr`` file from a FAT or ext2/3/4 filesystem
|
|
on external SD card or internal eMMC memory. If this fails or keyboard is
|
|
closed then the appended kernel image will be booted using some generated
|
|
and some stored ATAGs (see boot order).
|
|
|
|
For generating combined image of U-Boot and kernel (either in uImage or zImage
|
|
format) there is a simple script called ``u-boot-gen-combined``. It is available
|
|
in following repository: https://github.com/pali/u-boot-maemo.
|
|
|
|
To generate the ``combined.bin`` image from ``u-boot.bin`` and ``kernel.bin``
|
|
(in either uImage or zImage format) use:
|
|
|
|
.. code-block:: bash
|
|
|
|
sh u-boot-gen-combined u-boot.bin kernel.bin combined.bin
|
|
|
|
The original Maemo Fremantle PR1.3 zImage kernel binary is available at:
|
|
http://repository.maemo.org/pool/maemo5.0/free/k/kernel/kernel_2.6.28-20103103+0m5_armel.deb
|
|
|
|
To unpack it (from DEB/AR, TAR and FIASCO) execute the following commands:
|
|
|
|
.. code-block:: bash
|
|
|
|
ar x kernel_2.6.28-20103103+0m5_armel.deb data.tar.gz
|
|
tar -O -xf data.tar.gz ./boot/zImage-2.6.28-20103103+0m5.fiasco > kernel_2.6.28-20103103+0m5.fiasco
|
|
0xFFFF -M kernel_2.6.28-20103103+0m5.fiasco -u
|
|
|
|
The flashed image must start with a 2 KiB ``NOLO!img`` header which contains
|
|
size of the image. The header consists of the bytes
|
|
``NOLO!img\x02\x00\x00\x00\x00\x00\x00\x00`` followed by the 4 byte little
|
|
endian size of the image. The rest of the 2 KiB header just contains zero bytes.
|
|
|
|
The Nokia proprietary flasher and also the open source 0xFFFF flasher
|
|
automatically prepend the required ``NOLO!img`` header and both applications
|
|
expect that the image does not contain a ``NOLO!img`` header. Adding a
|
|
``NOLO!img`` header is required only in case of using the ``nandwrite`` tool for
|
|
flashing.
|
|
|
|
The open source 0xFFFF flasher is available in the following repository:
|
|
https://github.com/pali/0xFFFF
|
|
|
|
It is possible to load ``u-boot.bin`` via USB to the N900 RAM and boot it
|
|
without needing to flash it. This is done via 0xFFFF running on the host PC:
|
|
|
|
.. code-block:: bash
|
|
|
|
0xFFFF -m u-boot.bin -l -b
|
|
|
|
0xFFFF also supports flashing a kernel image either via USB or directly on
|
|
N900 device. Flashing u-boot/kernel/combined image is done as:
|
|
|
|
.. code-block:: bash
|
|
|
|
0xFFFF -m combined.bin -f
|
|
|
|
Via 0xFFFF it is also possible to generate a standard flashable image in
|
|
Nokia FIASCO format which contains metadata information like device
|
|
identification (RX-51) and version string (v2021.04):
|
|
|
|
.. code-block:: bash
|
|
|
|
0xFFFF -m RX-51:v2021.04:kernel:u-boot.bin -g u-boot.fiasco
|
|
|
|
There is support for the hardware watchdog. The hardware watchdog is started by
|
|
NOLO so U-Boot must reset the watchdog to prevent rebooting the device (but not
|
|
very often, max every 2 seconds). There is also support for framebuffer display
|
|
output with ANSI escape codes and the N900 hardware keyboard input.
|
|
|
|
When U-Boot is starting it sets the IBE bit in the Auxiliary Control Register,
|
|
which is needed for Thumb-2 ISA support. This is a workaround for erratum
|
|
430973.
|
|
|
|
Default boot order
|
|
------------------
|
|
|
|
0. if keyboard is closed boot automatically attached kernel image
|
|
1. try boot from external SD card
|
|
2. try boot from internal eMMC memory
|
|
3. try boot from attached kernel image
|
|
|
|
Boot from SD or eMMC in this order:
|
|
|
|
1. boot from FAT partition
|
|
|
|
a. find ``boot.scr`` on first FAT partition
|
|
b. find ``uImage`` on first FAT partition
|
|
c. find ``zImage`` on first FAT partition
|
|
d. same order for 2nd - 4th FAT partition
|
|
|
|
2. same as 1. but for ext2/3/4 partition
|
|
|
|
Available additional commands/variables
|
|
---------------------------------------
|
|
|
|
* run sdboot - Boot from external SD card (see boot order)
|
|
* run emmcboot - Boot from internal eMMC memory (see boot order)
|
|
* run attachboot - Boot attached kernel image (attached to U-Boot binary)
|
|
|
|
\
|
|
|
|
* run scriptload - Load boot script ``${mmcscriptfile}``
|
|
* run scriptboot - Run loaded boot script
|
|
* run kernload - Load kernel image ``${mmckernfile}``
|
|
* run initrdload - Load initrd image ``${mmcinitrdfile}``
|
|
* run kernboot - Boot loaded kernel image
|
|
* run kerninitrdboot - Boot loaded kernel image with loaded initrd image
|
|
|
|
\
|
|
|
|
* run trymmcscriptboot - Try to load and boot script ``${mmcscriptfile}``
|
|
* run trymmckernboot - Try to load and boot kernel image ``${mmckernfile}``
|
|
* run trymmckerninitrdboot - Try to load and boot kernel image ``${mmckernfile}``
|
|
with initrd image ``${mmcinitrdfile}``
|
|
|
|
Additional variables for loading files from mmc
|
|
-----------------------------------------------
|
|
|
|
* mmc ``${mmcnum}`` (0 - external, 1 - internal)
|
|
* partition number ``${mmcpart}`` (1 - 4)
|
|
* partition type ``${mmctype}`` (fat, ext2, ext4; ext2 is just alias for ext4)
|
|
|
|
Additional variables for booting a kernel
|
|
-----------------------------------------
|
|
|
|
* ``setup_omap_atag`` - Add OMAP table into atags structure (needed for maemo kernel)
|
|
* ``setup_console_atag`` - Enable serial console in OMAP table
|
|
* ``setup_boot_reason_atag`` - Change boot reason in OMAP table
|
|
* ``setup_boot_mode_atag`` - Change boot mode in OMAP table
|
|
|
|
Variable ``setup_omap_atag`` is automatically set when booting attached kernel.
|
|
When variable ``setup_omap_atag`` is set, variable ``setup_console_atag`` is unset
|
|
and u-boot standard output is set to serial then ``setup_console_atag`` is
|
|
automatically set to 1. So output from Maemo kernel would go to serial port.
|
|
|
|
UBIFS support
|
|
-------------
|
|
|
|
UBIFS support is disabled, because U-Boot image is too big and cannot be
|
|
flashed with attached kernel image to RX-51 kernel nand area. For enabling
|
|
UBIFS support add following lines into file ``configs/nokia_rx51_defconfig``::
|
|
|
|
CONFIG_CMD_UBI=y
|
|
CONFIG_CMD_UBIFS=y
|
|
CONFIG_MTD_UBI_BEB_LIMIT=10
|
|
|
|
Early output
|
|
------------
|
|
|
|
Early U-Boot output can be enabled on serial console by adding following lines
|
|
into file ``configs/nokia_rx51_defconfig``::
|
|
|
|
CONFIG_DEBUG_UART=y
|
|
CONFIG_DEBUG_UART_OMAP=y
|
|
CONFIG_DEBUG_UART_SHIFT=2
|
|
CONFIG_DEBUG_UART_BASE=0x49020000
|
|
CONFIG_DEBUG_UART_CLOCK=48000000
|
|
|
|
Note that early output is not available on USB tty console.
|
|
|
|
Verbose debug output
|
|
--------------------
|
|
|
|
Verbose debug output with maximal log level can be enabled by adding following
|
|
lines into file ``configs/nokia_rx51_defconfig``::
|
|
|
|
CONFIG_DM_DEBUG=y
|
|
CONFIG_LOG=y
|
|
CONFIG_LOGLEVEL=9
|
|
CONFIG_LOG_MAX_LEVEL=9
|
|
CONFIG_LOG_DEFAULT_LEVEL=9
|
|
|
|
And compiling U-Boot by additional make parameter ``KCPPFLAGS=-DLOG_DEBUG``.
|
|
|
|
Run in QEMU
|
|
-----------
|
|
|
|
Download and compile Linaro version of qemu which contains ``n900`` qemu
|
|
machine. Source code is available in qemu-linaro git repository and the
|
|
last working version is at commit 8f8d8e0796efe1a6f34cdd83fb798f3c41217ec1.
|
|
|
|
Use following commands to compile ``qemu-system-arm`` binary with ``n900``
|
|
qemu machine support:
|
|
|
|
.. code-block:: bash
|
|
|
|
git clone https://git.linaro.org/qemu/qemu-linaro.git
|
|
cd qemu-linaro
|
|
git checkout 8f8d8e0796efe1a6f34cdd83fb798f3c41217ec1
|
|
./configure --enable-system --target-list=arm-softmmu --disable-werror
|
|
make -j4
|
|
cd ..
|
|
ln -s qemu-linaro/arm-softmmu/qemu-system-arm .
|
|
|
|
Using ``n900`` qemu machine requires proprietary Nokia qemu ``qflasher`` tool
|
|
(in reality it is just generator of qemu MTD images) with first stage images
|
|
(``xloader-qemu.bin`` and ``secondary-qemu.bin``), similar what is required
|
|
on the real HW. License of flasher and images allows non-commercial
|
|
redistribution and it is available at maemo.org website:
|
|
|
|
.. code-block:: bash
|
|
|
|
wget -c http://repository.maemo.org/qemu-n900/qemu-n900.tar.gz
|
|
tar -xf qemu-n900.tar.gz
|
|
|
|
To generate qemu bootable MTD image ``mtd.img`` from U-Boot binary
|
|
``u-boot.bin`` and unpacked first stage images, run following command:
|
|
|
|
.. code-block:: bash
|
|
|
|
./qflasher -v -x xloader-qemu.bin -s secondary-qemu.bin -k u-boot.bin -m rx51 -o mtd.img
|
|
|
|
Instead of ``u-boot.bin`` binary it is possible to also used combined
|
|
U-Boot + kernel binary ``combined.bin``.
|
|
|
|
Finally, to boot ``mtd.img`` with graphics display and keyboard with optional
|
|
serial console on current terminal, run:
|
|
|
|
.. code-block:: bash
|
|
|
|
./qemu-system-arm -M n900 -mtdblock mtd.img -serial /dev/tty
|
|
|
|
Additionally it is possible to emulate also eMMC and uSD card by appending
|
|
qemu ``-sd`` arguments:
|
|
|
|
.. code-block:: bash
|
|
|
|
./qemu-system-arm -M n900 -mtdblock mtd.img -sd emmc.img -sd sd.img -serial /dev/tty
|
|
|
|
For more examples, look into the ``test/nokia_rx51_test.sh`` CI testing script.
|