/*
 * mono-hwcap-arm.c: ARM hardware feature detection
 *
 * Authors:
 *    Alex Rønne Petersen (alexrp@xamarin.com)
 *    Elijah Taylor (elijahtaylor@google.com)
 *    Miguel de Icaza (miguel@xamarin.com)
 *    Neale Ferguson (Neale.Ferguson@SoftwareAG-usa.com)
 *    Paolo Molaro (lupus@xamarin.com)
 *    Rodrigo Kumpera (kumpera@gmail.com)
 *    Sebastien Pouliot (sebastien@xamarin.com)
 *    Zoltan Varga (vargaz@xamarin.com)
 *
 * Copyright 2003 Ximian, Inc.
 * Copyright 2003-2011 Novell, Inc
 * Copyright 2006 Broadcom
 * Copyright 2007-2008 Andreas Faerber
 * Copyright 2011-2013 Xamarin Inc
 */

#include "mono/utils/mono-hwcap-arm.h"

#if defined(PLATFORM_ANDROID)
#include <stdio.h>
#elif defined(__linux__)
#include <sys/auxv.h>
#endif

gboolean mono_hwcap_arm_is_v5 = FALSE;
gboolean mono_hwcap_arm_is_v6 = FALSE;
gboolean mono_hwcap_arm_is_v7 = FALSE;
gboolean mono_hwcap_arm_is_v7s = FALSE;
gboolean mono_hwcap_arm_has_vfp = FALSE;
gboolean mono_hwcap_arm_has_thumb = FALSE;
gboolean mono_hwcap_arm_has_thumb2 = FALSE;

void
mono_hwcap_init (void)
{
#if defined(PLATFORM_ANDROID)
	/* We can't use the auxiliary vector on Android due to
	 * permissions, so fall back to /proc/cpuinfo.
	 */

	char buf [512];
	char *line;

	FILE *file = fopen ("/proc/cpuinfo", "r");

	if (file) {
		while ((line = fgets (buf, 512, file))) {
			if (!strncmp (line, "Processor", 9)) {
				char *ver = strstr (line, "(v");

				if (ver) {
					if (ver [2] >= '5')
						mono_hwcap_arm_is_v5 = TRUE;

					if (ver [2] >= '6')
						mono_hwcap_arm_is_v6 = TRUE;

					if (ver [2] >= '7')
						mono_hwcap_arm_is_v7 = TRUE;

					/* TODO: Find a way to detect v7s. */
				}

				continue;
			}

			if (!strncmp (line, "Features", 8)) {
				char *thumb = strstr (line, "thumb");

				if (thumb)
					mono_hwcap_arm_has_thumb = TRUE;

				/* TODO: Find a way to detect Thumb 2. */

				char *vfp = strstr (line, "vfp")

				if (vfp)
					mono_hwcap_arm_has_vfp = TRUE;

				continue;
			}
		}

		fclose (file);
	}
#elif defined(__linux__)
	unsigned long hwcap;
	unsigned long platform;

	if ((hwcap = getauxval(AT_HWCAP))) {
		/* HWCAP_ARM_THUMB */
		if (hwcap & 0x00000004)
			mono_hwcap_arm_has_thumb = TRUE;

		/* HWCAP_ARM_VFP */
		if (hwcap & 0x00000064)
			mono_hwcap_arm_has_vfp = TRUE;

		/* TODO: Find a way to detect Thumb 2. */
	}

	if ((platform = getauxval(AT_PLATFORM))) {
		const char *str = (const char *) platform;

		if (str [1] >= '5')
			mono_hwcap_arm_is_v5 = TRUE;

		if (str [1] >= '6')
			mono_hwcap_arm_is_v6 = TRUE;

		if (str [1] >= '7')
			mono_hwcap_arm_is_v7 = TRUE;

		/* TODO: Find a way to detect v7s. */
	}
#endif
}