The init.rc file will pass through the import/init.${ro.hardware}.rc file, and this ro.hardware should be a detailed attribute. This ro.hardware assignment should be assigned in the INIT process.
This Ro.hardware value setting is implemented in/SYSTEM/CORE/INIT.C and is assigned by hardware. Hardware is first assigned to/proc/cpuinfo. The comandline will then be detected.
Assuming that there are androidboot.hardware in the Comandline, the parameter will be used in the parsing of the Init process and will be assigned to hardware.
That is to say that there are androidboot.hardware in CmdLine. Then the value of Ro.hardware is this value, assuming no ro.hardware value is/proc/cpuinfo
For example, I am participating in this project comandline Androidboot.hardware = QILIANP1, then import in init.rc the detailed file corresponding to, init.qilianp1.rc
Parsing problems with init.rc files in Android