On Sunday 22 November 2015 19:47:05 Russell King - ARM Linux wrote: > On Sun, Nov 22, 2015 at 08:25:27PM +0100, Arnd Bergmann wrote: > > The question is really about Marvell Dove, MMP and Armada 370, > > which are all based on PJ4 or PJ4B (CPU part : 0x581), so ARMv7-A > > and report idivt support but idiva. > > Well, it's pretty hard to test when binutils blocks your ability to > write assembly using the instructions. > > root@cubox:~# gcc -O2 -o idiv idiv.c -Wa,-mcpu='cortex-a9+idiv' -marm > /tmp/cc8WPQiB.s: Assembler messages: > /tmp/cc8WPQiB.s:32: Error: selected processor does not support ARM mode `udiv ip,r5,r4' > root@cubox:~# gcc -O2 -o idiv idiv.c -Wa,-mcpu='cortex-a9+idiv' -mthumb > /tmp/ccRzgAlM.s: Assembler messages: > /tmp/ccRzgAlM.s:36: Error: selected processor does not support Thumb mode `udiv r6,r5,r4' > root@cubox:~# gcc -O2 -o idiv idiv.c -Wa,-mcpu='marvell-pj4+idiv' -mthumb > /tmp/cc1JYyFD.s: Assembler messages: > /tmp/cc1JYyFD.s:36: Error: selected processor does not support Thumb mode `udiv r6,r5,r4' > root@cubox:~# gcc -O2 -o idiv idiv.c -Wa,-mcpu='marvell-pj4+idiv' -marm > /tmp/ccEQbQpp.s: Assembler messages: > /tmp/ccEQbQpp.s:32: Error: selected processor does not support ARM mode `udiv ip,r5,r4' > > That's binutils 2.24 and gcc 4.8.4 as found on Ubuntu 14.04. I'm > sorry, but I don't have spare time to work out what the opcodes > would be. > does it work with -mcpu=cortex-a15? I've tried crosstool as versions 2.23.52.20130913, 2.24.0.20141017 and 2.25.51.20150518, and they all seem to behave as expected, failing with -mcpu=cortex-a9 and marvell-pj4 but succeeding with -mcpu=cortex-a15 or marvell-pj4+idiv. I've also found some /proc/cpuinfo output to cross-reference SoCs to their core names. variant part revision name features mmp2: 0 0x581 5 PJ4 idivt dove: 0 0x581 5 PJ4 idivt Armada 370 1 0x581 1 PJ4B idivt mmp3: 2 0x584 2 PJ4-MP idiva idivt lpae Armada XP 2 0x584 2 PJ4-MP idiva idivt lpae Berlin 2 0x584 2 PJ4-MP idiva idivt lpae Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
