My apologies, my statement this morning was not quite accurate. SMC is only implemented as part of the security extensions feature. As such it is not part of the base-line ARMv7-A architecture. To enable this feature you need to specify -march=armv7-a+sec (provided your toolchain supports that). You should also be able to enable it if you build with -march=armv7ve (which includes SEC by default), or if you take the -march= statement out of the list of options below and rely on picking up the architecture from the -mcpu statement (your current command line options are slightly in conflict, since Cortex-A15 implements the ARMv7VE version of the architecture). Note that SMC will be treated as undefined if executed from user mode; user code cannot call directly into the monitor. But that's a different issue. Once again, apologies for misleading you earlier. R. On 31/07/15 14:10, Shahin Ansari wrote: > Thanks. The following are the flags I am using; I do not see what I am doing > wrong. Would you have a look? > LOCAL_CFLAGS := -march=armv7-a -mtune=cortex-a15 -D__ASSEMBLY__ > -mabi=aapcs-linux -gdwarf-2 -Wall -Wundef -Wstrict-proto > types -Wno-trigraphs -fno-strict-aliasing -fno-common > -Werror-implicit-function-declaration -Wno-format-security -fno-de > lete-null-pointer-checks -Os -Wno-maybe-uninitialized -marm > -fno-dwarf2-cfi-asm -fstack-protector -mabi=aapcs-linux -mno > -thumb-interwork -funwind-tables -D__LINUX_ARM_ARCH__=7 -mcpu=cortex-a15 > -msoft-float -Uarm -Wframe-larger-than=1024 -Wn > o-unused-but-set-variable -fomit-frame-pointer -g > -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow - > fconserve-stack -DCC_HAVE_ASM_GOTO > > -----Original Message----- > From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On > Behalf Of Richard Earnshaw > Sent: Friday, July 31, 2015 5:46 AM > To: Shahin Ansari <shansari@xxxxxxxxxxx>; gcc-help@xxxxxxxxxxx > Subject: Re: what options to pass to gcc for support of arm security > extensions > > On 30/07/15 20:29, Shahin Ansari wrote: >> Greetings- >> According to the ARM documentation the SMC call should be supported at >> ARMv6 and above. However, I get the error message below when I try to use > it: >> > > Almost, it's ARMv6Z that introduced the SMC instruction. It will certainly > be recognized for ARMv7-a and above. > > GCC uses the -mcpu= (or if that's not specified the -march=) options from > the command line to tell the assembler what instructions should be > permitted. > > R. >
