From 1011e3a3d31a20aa44dcd8b5c257659e7e336b7e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ga=C3=ABl=20PORTAY?= Date: Tue, 15 Apr 2025 17:31:23 +0200 Subject: [PATCH] board/raspberrypi/readme.txt: reword overlays note MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Any Raspberry Pi may use device-tree overlays; it is not restricted to Raspberry Pi 3 and 4. The defconfigs for the Raspberry Pi 3, 4, 400, Zero W, Zero 2 W, Compute Module 4 and 4s use the miniuart-bt dtoverlay to switch the Bluetooth to the mini-UART (ttyS0) and restore UART0 (ttyAMA0) over GPIOs 14 and 15 to enable the serial console (like the Raspberry Pi 1 and 2 that have no Bluetooth)[1][2]. As a consequence, the Raspberry Pi Zero W, Zero 2 W, 400, Compute Module 4 and 4s install the device-tree overlays as well. This rewords the note by adding the three missing hardwares installing the images/rpi-firmware/overlays directory. It rewords the miniuart note at the same time. [1]: https://www.raspberrypi.com/documentation/computers/configuration.html#uarts-and-device-tree [2]: https://github.com/raspberrypi/linux/blob/rpi-6.6.y/arch/arm/boot/dts/overlays/miniuart-bt-overlay.dts#L4-L6 Signed-off-by: Gaël PORTAY Signed-off-by: Julien Olivain (cherry picked from commit a642bed09afdfce42a7063e38c2e10beddbed5ef) Signed-off-by: Thomas Perale --- board/raspberrypi/readme.txt | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/board/raspberrypi/readme.txt b/board/raspberrypi/readme.txt index 5f6b1c3e7d..0f3ec9d8bb 100644 --- a/board/raspberrypi/readme.txt +++ b/board/raspberrypi/readme.txt @@ -131,10 +131,11 @@ After building, you should obtain this tree: Pi 4, 400, 5 and the Compute Module 4, 4s and 5 load the second stage bootloader from a SPI flash EEPROM. -[3] Only for the Raspberry Pi 3/4 Models (overlay miniuart-bt is needed - to enable the RPi3 serial console otherwise occupied by the bluetooth - chip). Alternative would be to disable the serial console in cmdline.txt - and /etc/inittab. +[3] Only for the Raspberry Pi installing device-tree overlays. The Raspberry Pi + with Bluetooth connectivity (Zero W, Zero 2 W, 3, 4, 400, Compute Module 4 + and 4s) use the miniuart-bt overlay to enable UART0 for the serial console; + the Bluetooth uses the mini-UART instead. Alternative would be to disable + the serial console in cmdline.txt and /etc/inittab. How to write the SD card ========================