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| author | Mohd Noor Aman <nooraman5718@gmail.com> | 2022-10-08 22:49:40 +0530 |
|---|---|---|
| committer | Joel Sherrill <joel@rtems.org> | 2022-10-08 09:31:53 -0500 |
| commit | f13489efb43ddafc96ee63e240e68e0253d8ef02 (patch) | |
| tree | fbe1f797ed08add365c0af52766710db83dc0172 /user/bsps | |
| parent | raspberrypi4.rst: Documentation for the new AArch64 Raspberry pi 4B BSP (diff) | |
| download | rtems-docs-f13489efb43ddafc96ee63e240e68e0253d8ef02.tar.bz2 | |
user/aarch64/raspberrypi4: Boot mechanism explained and updated config.txt
Diffstat (limited to 'user/bsps')
| -rw-r--r-- | user/bsps/aarch64/raspberrypi4.rst | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/user/bsps/aarch64/raspberrypi4.rst b/user/bsps/aarch64/raspberrypi4.rst index 729d71b..efb09b6 100644 --- a/user/bsps/aarch64/raspberrypi4.rst +++ b/user/bsps/aarch64/raspberrypi4.rst @@ -34,10 +34,14 @@ raspberrypi hardware. Mini-uart is not supported. Preparing to boot ------------------ -Raspberry Pi uses a different mechanism to boot. First the GPU initializes, -loads the bootloader and then looks for the kernel img. By default the arm64 -mode looks for the ``kernel8.img``. Any other kernel can be loaded by adding -``kernel=<img_name>`` to the ``config.txt`` file. +Raspberry Pi uses a different mechanism to boot when compared with any ARM SoC. +First the GPU initializes, loads the bootloader (Raspberry pi firmware) and then +looks for the kernel img. This whole process is done by the GPU (VideoCore IV) +till the kernel is loaded. More information can be found on the `Raspberry pi +documentation page +<https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#boot-sequence>`_. +By default the arm64 mode looks for the ``kernel8.img``. Any other kernel can be +loaded by adding ``kernel=<img_name>`` to the ``config.txt`` file. The Firmware files are required in order to boot RTEMS. The latest firmware can be downloaded from the `Raspberry Pi Firmware Repository @@ -56,6 +60,9 @@ default Mini-uart. .. code-block:: none + # if user wants to enable GIC, uncomment the next line + # enable_gic=1 + arm_64bit=1 dtoverlay = disable-bt enable_uart=1 |