*              general use.
  *****************************************************************************/
 setup_auxcr:
+       mrc     p15, 0, r0, c0, c0, 0           @ read main ID register
+       and     r2, r0, #0x00f00000             @ variant
+       and     r3, r0, #0x0000000f             @ revision
+       orr     r1, r3, r2, lsr #20-4           @ combine variant and revision
        mov     r12, #0x3
        mrc     p15, 0, r0, c1, c0, 1
        orr     r0, r0, #0x10                   @ Enable ASA
-       orr     r0, r0, #1 << 5                 @ Enable L1NEON
+       @ Enable L1NEON on pre-r2p1 (erratum 621766 workaround)
+       cmp     r1, #0x21
+       orrlt   r0, r0, #1 << 5
        .word 0xE1600070                        @ SMC
        mov     r12, #0x2
        mrc     p15, 1, r0, c9, c0, 2
-       @ Set PLD_FWD bit in L2AUXCR (Cortex-A8 erratum 725233 workaround)
-       orr     r0, r0, #1 << 27
+       @ Set PLD_FWD bit in L2AUXCR on pre-r2p1 (erratum 725233 workaround)
+       cmp     r1, #0x21
+       orrlt   r0, r0, #1 << 27
        .word 0xE1600070                        @ SMC
        bx      lr