The attached tcl script (stub.tcl) creates a stub for the second CPU core. The second CPU core executes a wfe (wait for event) instruction and waits for the first CPU core to wake up.
If the first processor wants to wake up the second core, it just needs to write the desired pc value at location 0xFFFFFFF0 and send a sev (send event) instruction.
Without this, Linux might not boot, since the boot rom has a bug in jtag mode for rev1 of the silicon. Therefore, this step is needed when Linux is being loaded directly into RAM without booting from flash.
Following is the assembly code that the second CPU core executes:
0xFFFFFF00: mvn r0, #15
0xFFFFFF04: mov r1
0xFFFFFF08: str r1, [r0]
0xFFFFFF10: ldr r2, [r0]
0xFFFFFF14: cmp r2, r1
0xFFFFFF18: beq 0xc
0xFFFFFF1C: mov pc