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| author | Alex Bennée <alex.bennee@linaro.org> | 2021-02-02 13:39:59 +0000 |
|---|---|---|
| committer | Alex Bennée <alex.bennee@linaro.org> | 2021-02-08 10:55:20 +0000 |
| commit | a5dbb175077c93c8d2e1021757f8b9a593fc2b5e (patch) | |
| tree | 4c89e36e68e202e3cf158b2d70acf7677851d62a /docs | |
| parent | c401c058a1cdb131163751f29df9151290d842b0 (diff) | |
docs/system: document an example vexpress-a15 invocation
The wiki and the web are curiously absent of the right runes to boot a
vexpress model so I had to work from first principles to work it out.
Use the more modern -drive notation so alternative backends can be
used (unlike the hardwired -sd mode).
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Message-Id: <20210202134001.25738-15-alex.bennee@linaro.org>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/system/arm/vexpress.rst | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/docs/system/arm/vexpress.rst b/docs/system/arm/vexpress.rst index 7f1bcbef07..3e3839e923 100644 --- a/docs/system/arm/vexpress.rst +++ b/docs/system/arm/vexpress.rst @@ -58,3 +58,31 @@ Other differences between the hardware and the QEMU model: ``vexpress-a15``, and have IRQs from 40 upwards. If a dtb is provided on the command line then QEMU will edit it to include suitable entries describing these transports for the guest. + +Booting a Linux kernel +---------------------- + +Building a current Linux kernel with ``multi_v7_defconfig`` should be +enough to get something running. Nowadays an out-of-tree build is +recommended (and also useful if you build a lot of different targets). +In the following example $BLD points to the build directory and $SRC +points to the root of the Linux source tree. You can drop $SRC if you +are running from there. + +.. code-block:: bash + + $ make O=$BLD -C $SRC ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- multi_v7_defconfig + $ make O=$BLD -C $SRC ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- + +By default you will want to boot your rootfs off the sdcard interface. +Your rootfs will need to be padded to the right size. With a suitable +DTB you could also add devices to the virtio-mmio bus. + +.. code-block:: bash + + $ qemu-system-arm -cpu cortex-a15 -smp 4 -m 4096 \ + -machine type=vexpress-a15 -serial mon:stdio \ + -drive if=sd,driver=file,filename=armel-rootfs.ext4 \ + -kernel zImage \ + -dtb vexpress-v2p-ca15-tc1.dtb \ + -append "console=ttyAMA0 root=/dev/mmcblk0 ro" |