Build Instructions Out-of-Date

[Brandon-Hurst]

The current build instructions point here at the time of writing:
https://analogdevicesinc.github.io/linux/getting_started.html#how-to-build

This links to our DocuWiki page here:
https://wiki.analog.com/resources/tools-software/linux-build/generic/raspberrypi

These instructions are currently out-of-date and have a few major problems. In order, here are some things I noticed:

• Instructions clone raspberrypi/tools which uses a deprecated GCC toolchain. The recommendation here is to instead install the latest apt package e.g. sudo apt-get install gcc-arm-linux-gnueabihf.
• CROSS_COMPILE build variable is called out as "path to cross-compile toolchain" which is not correct. This variable is the prefix to the toolchain to use. For example, if using arm-linux-gnueabihf-gcc, then one would write CROSS_COMPILE=arm-linux-gnueabihf- when building.
• A couple dependencies are missing (may have been added since). For building, flex and bison are required and may be installed with apt e.g. sudo apt-get install flex bison. For menuconfig libncurses5-dev is also needed e.g. sudo apt-get install libncurses5-dev. The current page doesn't mention dependency installs.
• The defconfigs shown do not include adi modifications. For example, under arch/arm/config, there exist adi_bcm2711_defconfig files as opposed to bcm2711_defconfig. I'm assuming these may make patches required for some ADI drivers?
• More of a suggestion, but possibly cloning a single branch or using lower fetch depth could speed up the process significantly due to the sheer amount of branches and history.

As a reference, I used these steps to build a kernel with the rpi-6.12.y branch:

# Install dependencies and up-to-date gcc toolchain 
sudo apt-get install gcc-arm-linux-gnueabihf flex bison libncurses5-dev

# Clone the repository (single branch, low depth for speed)
git clone --branch rpi-6.12.y --single-branch --depth 1 https://github.com/analogdevicesinc/linux.git linux-adi
cd linux-adi

# Config for e.g. RPi Compute Module 4
ARCH=arm make adi_bcm2711_defconfig

# Build kernel
ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make

[gastmaier]

yep that page should not exist as is, will update it and make it more interesting.

[gastmaier]

https://analogdevicesinc.github.io/linux/pull/3309/getting_started.html