/*
$ gcc arm-fpu.c
$ ./a.out
machdep.fpu_present=1
machdep.fpu_id=0x410120b5
machdep.neon_present=0
FPU model=VFP11

Raspberry Pi 1
*/

#include <sys/types.h>
#include <sys/sysctl.h>
#include <arm/vfpreg.h>
#include <stdio.h>
#include <stdlib.h>

int
main(int argc, char **argv)
{
	int fpu_present;
	uint32_t fpu_id;
	int neon_present;
	const char *model = NULL;
	size_t len;

	len = sizeof(fpu_present);
	if (sysctlbyname("machdep.fpu_present", &fpu_present, &len, NULL, 0) < 0)
		abort();

	printf("machdep.fpu_present=%d\n", fpu_present);
	if (fpu_present == 0)
		return 0;

	len = sizeof(fpu_id);
	if (sysctlbyname("machdep.fpu_id", &fpu_id, &len, NULL, 0) < 0)
		abort();

	printf("machdep.fpu_id=%#x\n", fpu_id);

	len = sizeof(neon_present);
	if (sysctlbyname("machdep.neon_present", &neon_present, &len, NULL, 0) < 0)
		abort();

	printf("machdep.neon_present=%d\n", neon_present);

	switch (fpu_id & ~ VFP_FPSID_REV_MSK) {
	case FPU_VFP10_ARM10E:
		model = "VFP10 R1";
		break;
	case FPU_VFP11_ARM11:
		model = "VFP11";
		break;
	case FPU_VFP_MV88SV58XX:
		model = "VFP3";
		break;
	case FPU_VFP_CORTEXA5:
	case FPU_VFP_CORTEXA7:
	case FPU_VFP_CORTEXA8:
	case FPU_VFP_CORTEXA9:
#ifdef FPU_VFP_CORTEXA12
	case FPU_VFP_CORTEXA12:
#endif
	case FPU_VFP_CORTEXA15:
	case FPU_VFP_CORTEXA15_QEMU:
#ifdef FPU_VFP_CORTEXA17
	case FPU_VFP_CORTEXA17:
#endif
	case FPU_VFP_CORTEXA53:
	case FPU_VFP_CORTEXA57:	
		if (!neon_present) {
			model = "VFP 4.0+";
		} else {
			model = "NEON MPE (VFP 3.0+)";
		}
		break;
	default:
		model = "unrecognized VFP version";
	}

	printf("FPU model=%s\n", model);

	return 0;
}