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Diffstat (limited to 'Documentation/boards/bcm2835.rst')
| -rw-r--r-- | Documentation/boards/bcm2835.rst | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/Documentation/boards/bcm2835.rst b/Documentation/boards/bcm2835.rst index e9ad1d4d57..f7ab723d63 100644 --- a/Documentation/boards/bcm2835.rst +++ b/Documentation/boards/bcm2835.rst @@ -4,25 +4,50 @@ Broadcom BCM283x Raspberry Pi ------------ +barebox has support for BCM283x-based Raspberry Pi single board computers. +Support is most extensive for BCM283[567], but barebox can also boot Linux +over SD or Ethernet on the Raspberry Pi 4. + 1. Prepare an SD or microSD card with a FAT filesystem of at least 30 MB in size. - 2. Download the `Raspberry Pi firmware`_ (120 MB), unzip it, and copy the + 2. Download the `Raspberry Pi firmware`_ (195 MB), unzip it, and copy the contents of the ``boot/`` folder to your card. - 3. Use ``make rpi_defconfig; make`` to build barebox. This will create the following images: + 3. Use ``make rpi_defconfig; make`` to build barebox for 32-bit boards or + ``make rpi_v8a_defconfig; make`` to build barebox for 64-bit. + + ``rpi_defconfig`` will build at least following images: - - ``images/barebox-raspberry-pi-1.img`` for the BCM2835/ARM1176JZF-S (Raspberry Pi 1) + - ``images/barebox-raspberry-pi-1.img`` for the BCM2835/ARM1176JZF-S (Raspberry Pi 1, Raspberry Pi Zero) - ``images/barebox-raspberry-pi-2.img`` for the BCM2836/CORTEX-A7 (Raspberry Pi 2) - - ``images/barebox-raspberry-pi-3.img`` for the BCM2837/CORTEX-A53 (Raspberry Pi 3, Raspberry Pi Zero) + - ``images/barebox-raspberry-pi-3.img`` for the BCM2837/CORTEX-A53 (Raspberry Pi 3) + - ``images/barebox-raspberry-pi-cm3.img`` for the BCM2837/CORTEX-A53 (Raspberry Pi CM3) + - ``images/barebox-raspberry-pi.img``, which is a super set of all the other images, + including Raspberry Pi 4 32-bit support. Copy the respective image for your model to your SD card and name it ``barebox.img``. + For 64-bit, only ``images/barebox-raspberry-pi.img`` will be created, which is usable + for both Raspberry Pi 3 and Raspberry Pi 4 in 64-bit mode. No support for the Raspberry + Pi 5 has been contributed yet. + + The ``images/barebox-raspberry-pi.img`` is expected to be the sole image for 32-bit + also in the future. It contains the device trees of all supported (and enabled) variants + and determines at runtime what board it runs on and does the right thing. + 4. Create a text file ``config.txt`` on the SD card with the following content:: kernel=barebox.img enable_uart=1 + If you want to use the mini-uart instead of the PL011, you may need to additionally set:: + + uart_2ndstage=1 + + This is required on boards, like the Raspberry Pi Zero W, that use the mini-uart as the + primary UART. It is needed on boards like the CM3 as well if the mini-uart is to be used. + (For more information, refer to the `documentation for config.txt`_.) 5. Connect to board's UART (115200 8N1); @@ -40,5 +65,5 @@ The original command-line from VideoCore device tree is available to the Barebox global linux.bootargs.vc="$global.vc.bootargs" -.. _Raspberry Pi firmware: https://codeload.github.com/raspberrypi/firmware/zip/80e1fbeb78f9df06701d28c0ed3a3060a3f557ef +.. _Raspberry Pi firmware: https://github.com/raspberrypi/firmware/archive/refs/tags/1.20220331.zip .. _documentation for config.txt: https://www.raspberrypi.org/documentation/configuration/config-txt/ |