| Message ID | 20191128143421.13815-1-drjones@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [kvm-unit-tests] arm: Enable the VFP | expand |
Doh, now I need another change to deal with older compilers diff --git a/arm/Makefile.arm b/arm/Makefile.arm index 43b4be1e05eeb..d379a28007493 100644 --- a/arm/Makefile.arm +++ b/arm/Makefile.arm @@ -5,7 +5,7 @@ # bits = 32 ldarch = elf32-littlearm -machine = -marm +machine = -marm -mfpu=vfp # stack.o relies on frame pointers. KEEP_FRAME_POINTER := y I'll send a v2 now. On Thu, Nov 28, 2019 at 03:34:21PM +0100, Andrew Jones wrote: > Variable argument macros frequently depend on floating point > registers. Indeed we needed to enable the VFP for arm64 since its > introduction in order to use printf and the like. Somehow we > didn't need to do that for arm32 until recently when compiling > with GCC 9. > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > > CC'ing Thomas because I think he had to workaround travis tests > failing due to this issue once. Maybe travis can now be > un-worked-around? > > > arm/cstart.S | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/arm/cstart.S b/arm/cstart.S > index 114726feab82..bc6219d8a3ee 100644 > --- a/arm/cstart.S > +++ b/arm/cstart.S > @@ -50,10 +50,11 @@ start: > mov r0, r2 > push {r0-r1} > > - /* set up vector table and mode stacks */ > + /* set up vector table, mode stacks, and enable the VFP */ > mov r0, lr @ lr is stack top (see above), > @ which is the exception stacks base > bl exceptions_init > + bl enable_vfp > > /* complete setup */ > pop {r0-r1} > @@ -100,6 +101,16 @@ exceptions_init: > isb > mov pc, lr > > +enable_vfp: > + /* Enable full access to CP10 and CP11: */ > + mov r0, #(3 << 22 | 3 << 20) > + mcr p15, 0, r0, c1, c0, 2 > + isb > + /* Set the FPEXC.EN bit to enable Advanced SIMD and VFP: */ > + mov r0, #(1 << 30) > + vmsr fpexc, r0 > + mov pc, lr > + > .text > > .global get_mmu_off > @@ -130,6 +141,7 @@ secondary_entry: > ldr r0, [r1] > mov sp, r0 > bl exceptions_init > + bl enable_vfp > > /* finish init in C code */ > bl secondary_cinit > -- > 2.21.0 >
On 28/11/2019 15.34, Andrew Jones wrote: > Variable argument macros frequently depend on floating point > registers. Indeed we needed to enable the VFP for arm64 since its > introduction in order to use printf and the like. Somehow we > didn't need to do that for arm32 until recently when compiling > with GCC 9. > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > > CC'ing Thomas because I think he had to workaround travis tests > failing due to this issue once. Maybe travis can now be > un-worked-around? Yes, this patch fixes the problem with GCC9 for me: https://gitlab.com/huth/kvm-unit-tests/-/jobs/364079089 Feel free to add my Tested-by: Thomas Huth <thuth@redhat.com> and if you like, please also include this hunk: diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml --- a/.gitlab-ci.yml +++ b/.gitlab-ci.yml @@ -17,7 +17,7 @@ build-aarch64: build-arm: script: - - dnf install -y qemu-system-arm gcc-arm-linux-gnu-8.2.1-1.fc30.2 + - dnf install -y qemu-system-arm gcc-arm-linux-gnu - ./configure --arch=arm --cross-prefix=arm-linux-gnu- - make -j2 - ACCEL=tcg ./run_tests.sh Thomas
diff --git a/arm/cstart.S b/arm/cstart.S index 114726feab82..bc6219d8a3ee 100644 --- a/arm/cstart.S +++ b/arm/cstart.S @@ -50,10 +50,11 @@ start: mov r0, r2 push {r0-r1} - /* set up vector table and mode stacks */ + /* set up vector table, mode stacks, and enable the VFP */ mov r0, lr @ lr is stack top (see above), @ which is the exception stacks base bl exceptions_init + bl enable_vfp /* complete setup */ pop {r0-r1} @@ -100,6 +101,16 @@ exceptions_init: isb mov pc, lr +enable_vfp: + /* Enable full access to CP10 and CP11: */ + mov r0, #(3 << 22 | 3 << 20) + mcr p15, 0, r0, c1, c0, 2 + isb + /* Set the FPEXC.EN bit to enable Advanced SIMD and VFP: */ + mov r0, #(1 << 30) + vmsr fpexc, r0 + mov pc, lr + .text .global get_mmu_off @@ -130,6 +141,7 @@ secondary_entry: ldr r0, [r1] mov sp, r0 bl exceptions_init + bl enable_vfp /* finish init in C code */ bl secondary_cinit
Variable argument macros frequently depend on floating point registers. Indeed we needed to enable the VFP for arm64 since its introduction in order to use printf and the like. Somehow we didn't need to do that for arm32 until recently when compiling with GCC 9. Signed-off-by: Andrew Jones <drjones@redhat.com> --- CC'ing Thomas because I think he had to workaround travis tests failing due to this issue once. Maybe travis can now be un-worked-around? arm/cstart.S | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)