ahh okay. The code I don't think writes to CPACR_EL1 register, but it runs on the hardware anywary.
I`ll double check. Thanks for the tip. Best regards, Karthik On Tue, May 24, 2016 at 7:07 PM, Peter Maydell <peter.mayd...@linaro.org> wrote: > On 24 May 2016 at 14:07, Karthik <karthikshanmu...@gmail.com> wrote: > > I am working on adding support for a Spansion microcontroller which has > an > > Cortex R5 core + VFP3 co processor. > > > > I have added the below line > > set_feature(&cpu->env, ARM_FEATURE_VFP3) > > to cortex_r5_initfn at /target-arm/cpu.c > > > > But, still I got undefined exception when the processor encountered any > VFP > > instructions. > > Has your guest code actually enabled the floating point? > It needs to write to CPACR_EL1 itself to set the FPEXC bit. Otherwise > we will correctly generate an exception, just as the real hardware > will. The code you mention is in CONFIG_USER_ONLY because if we > are only emulating a user process then we simulate the behaviour that > a Linux kernel has of setting the CPACR correctly. For system > emulation setting the bit is the guest code's responsibility. > > thanks > -- PMM >
