Petalinux is brand name used by Xilinx, it is based on Yocto and pretty decent mainstream kernel, what Petalinux adds is the HSI (Hardware Software Interface from Vivado) and special tools for boot image creation.
Please check Petalinux Installation Guide
Note: it is recommended to test the installation by creating a dummy template project and building it.
Most settings can be changed with menu-config. There are 3 more files that user can edit, they are
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