On Fri, Jan 09, 2015 at 10:16:32AM +0800, Wang, Yalin wrote: > > -----Original Message----- > > From: Russell King - ARM Linux [mailto:[email protected]] > > Sent: Friday, January 09, 2015 2:41 AM > > To: Wang, Yalin > > Cc: 'Will Deacon'; 'Ard Biesheuvel'; '[email protected]'; > > '[email protected]'; '[email protected]'; 'Joe Perches'; 'linux-arm- > > [email protected]' > > Subject: Re: [RFC V6 2/3] arm:add bitrev.h file to support rbit instruction > > > > The root cause is that the kernel being built is supposed to support both > > ARMv7 and ARMv6K CPUs. However, "rbit" is only available on > > ARMv6T2 (thumb2) and ARMv7, and not plain ARMv6 or ARMv6K CPUs. > > > In the patch that you applied: > 8205/1 add bitrev.h file to support rbit instruction > > I have add : > + select HAVE_ARCH_BITREVERSE if ((CPU_V7M || CPU_V7) && !CPU_V6) > > If you build kernel support ARMv6K, should CONFIG_CPU_V6=y, isn't it ? > Then will not build hardware rbit instruction, isn't it ?
The config has: CONFIG_CPU_PJ4=y # CONFIG_CPU_V6 is not set CONFIG_CPU_V6K=y CONFIG_CPU_V7=y CONFIG_CPU_32v6=y CONFIG_CPU_32v6K=y CONFIG_CPU_32v7=y And no, the CONFIG_CPU_V* flags refer to the CPUs. The CONFIG_CPU_32v* symbols refer to the CPU architectures. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
