ps2rom/rom/rom_start.s

// This is the entry point of the ROM.
// It is limited to 32-bit MIPS-I code,
// because it runs on both the EE and the IOP.
//
// The task of this relatively short bit of code
// is to start the approiate part of the ROM
// on the correct processor.
//
// It's a bit creative, but also a bit annoying.
.org 0
.set noat

// externs from each piece of the code
.extern _ee_start
.extern _iop_start

.globl _start
_start:
	mfc0 $at, $15		// load the PRID
	sltiu $at, 0x59		// Check for EE PRID
	bne $15, 0, __iop	// Branch if not EE
	nop
	j _ee_start			// Call EE start routine
	nop
__iop:
	j __iop
	//j _iop_start		// Call IOP start routine
	//nop