Le 08/07/2022 à 22:04, Arnd Bergmann a écrit : > On Fri, Jul 8, 2022 at 7:12 PM Pali Rohár <p...@kernel.org> wrote: >> >> On Monday 04 July 2022 14:07:10 Arnd Bergmann wrote: >>> Another problem I see is that a kernel that is built for both E500 and >>> E500MC >>> uses -mcpu=e500mc and may not actually work on the older ones either >>> (even with your patch). >> >> Such configuration is not supported, see >> arch/powerpc/platforms/Kconfig.cputype: >> >> config PPC_E500MC >> bool "e500mc Support" >> select PPC_FPU >> select COMMON_CLK >> depends on E500 >> help >> This must be enabled for running on e500mc (and derivatives >> such as e5500/e6500), and must be disabled for running on >> e500v1 or e500v2. >> >> Based on this option you can enable either support for e500v1/e500v2 or >> for e500mc. But not both. > > This looks like a bad decision in Kconfig though, as there is nothing > enforcing the rule: If you want support for E500MC, you have to select > PPC_85xx, which implies E500 and allows selecting any combination > of E500v1, E500v2 and E500MC based machines, but enabling > any E500MC based one breaks all the others. > > If this is a hard dependency, I think it should be enforced by making > E500MC a separate top-level option in the "Processor Type" choice > statement. However, if they can actually coexist, the help text and > the Makefile need to be fixed. >
While looking at this discussion, I discovered that with GCC 12 from https://mirrors.edge.kernel.org/pub/tools/crosstool/ I'm unable to build a corenet64_smp_defconfig: If I select the GENERIC_CPU or e5500 (with altivec) I get: CC arch/powerpc/kernel/irq.o {standard input}: Assembler messages: {standard input}:3535: Error: unrecognized opcode: `wrteei' {standard input}:5608: Error: unrecognized opcode: `wrteei' CC arch/powerpc/kernel/pmc.o {standard input}: Assembler messages: {standard input}:42: Error: unrecognized opcode: `mfpmr' {standard input}:53: Error: unrecognized opcode: `mtpmr' If I select the e5500 (without altivec) or e6500 I get: CC arch/powerpc/kernel/io.o {standard input}: Assembler messages: {standard input}:381: Error: unrecognized opcode: `eieio' {standard input}:444: Error: unrecognized opcode: `eieio' {standard input}:480: Error: unrecognized opcode: `eieio' {standard input}:506: Error: unrecognized opcode: `eieio' {standard input}:552: Error: unrecognized opcode: `eieio' {standard input}:817: Error: unrecognized opcode: `eieio' {standard input}:839: Error: unrecognized opcode: `eieio' {standard input}:885: Error: unrecognized opcode: `eieio' {standard input}:1106: Error: unrecognized opcode: `eieio' {standard input}:1130: Error: unrecognized opcode: `eieio' {standard input}:1174: Error: unrecognized opcode: `eieio' {standard input}:1393: Error: unrecognized opcode: `eieio' {standard input}:1417: Error: unrecognized opcode: `eieio' {standard input}:1461: Error: unrecognized opcode: `eieio' Christophe