I don't think iOS has any similarity to booting an x86 CPU by faking an SPI Flash chip, compiling the IBB, ME and BUP code on-the-fly as needed and validating i

I don't think iOS has any similarity to booting an x86 CPU by faking an SPI Flash chip, compiling the IBB, ME and BUP code on-the-fly as needed and validating it externally before feeding it to the ROM inside the CPU for loading and microcode installation. But the T1, T2 itself is similar to iOS, as is the initial M1 boot stage.