static unsigned long get_hwcap_cpuinfo(const STRING_PIECE *cpuinfo) {
if (cpuinfo_field_equals(cpuinfo, "CPU architecture", "8")) {
/* This is a 32-bit ARM binary running on a 64-bit kernel. NEON is always
* available on ARMv8. Linux omits required features, so reading the
* "Features" line does not work. (For simplicity, use strict equality. We
* assume everything running on future ARM architectures will have a
* working |getauxval|.) */
return HWCAP_NEON;
}
STRING_PIECE features;
if (extract_cpuinfo_field(&features, cpuinfo, "Features") &&
has_list_item(&features, "neon")) {
return HWCAP_NEON;
}
return 0;
}
static unsigned long get_hwcap2_cpuinfo(const STRING_PIECE *cpuinfo) {
STRING_PIECE features;
if (!extract_cpuinfo_field(&features, cpuinfo, "Features")) {
return 0;
}
unsigned long ret = 0;
if (has_list_item(&features, "aes")) {
ret |= HWCAP2_AES;
}
if (has_list_item(&features, "pmull")) {
ret |= HWCAP2_PMULL;
}
if (has_list_item(&features, "sha1")) {
ret |= HWCAP2_SHA1;
}
if (has_list_item(&features, "sha2")) {
ret |= HWCAP2_SHA2;
}
return ret;
}
static int cpuinfo_field_equals(const STRING_PIECE *cpuinfo, const char *field,
const char *value) {
STRING_PIECE extracted;
return extract_cpuinfo_field(&extracted, cpuinfo, field) &&
STRING_PIECE_equals(&extracted, value);
}
static void
android_cpuInit(void)
{
char cpuinfo[4096];
int cpuinfo_len;
g_cpuFamily = DEFAULT_CPU_FAMILY;
g_cpuFeatures = 0;
g_cpuCount = 1;
cpuinfo_len = read_file("/proc/cpuinfo", cpuinfo, sizeof cpuinfo);
D("cpuinfo_len is (%d):\n%.*s\n", cpuinfo_len,
cpuinfo_len >= 0 ? cpuinfo_len : 0, cpuinfo);
if (cpuinfo_len < 0) /* should not happen */ {
return;
}
/* Count the CPU cores, the value may be 0 for single-core CPUs */
g_cpuCount = count_cpuinfo_field(cpuinfo, cpuinfo_len, "processor");
if (g_cpuCount == 0) {
g_cpuCount = count_cpuinfo_field(cpuinfo, cpuinfo_len, "Processor");
if (g_cpuCount == 0) {
g_cpuCount = 1;
}
}
D("found cpuCount = %d\n", g_cpuCount);
#ifdef __arm__
{
char* features = NULL;
char* architecture = NULL;
/* Extract architecture from the "CPU Architecture" field.
* The list is well-known, unlike the the output of
* the 'Processor' field which can vary greatly.
*
* See the definition of the 'proc_arch' array in
* $KERNEL/arch/arm/kernel/setup.c and the 'c_show' function in
* same file.
*/
char* cpuArch = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "CPU architecture");
if (cpuArch != NULL) {
char* end;
long archNumber;
int hasARMv7 = 0;
int hasARMv6 = 0;
D("found cpuArch = '%s'\n", cpuArch);
/* read the initial decimal number, ignore the rest */
archNumber = strtol(cpuArch, &end, 10);
D("found archNumber = '%d'\n", archNumber);
/* Here we assume that ARMv8 will be upwards compatible with v7
* in the future. Unfortunately, there is no 'Features' field to
* indicate that Thumb-2 is supported.
*/
if (end > cpuArch ){
if (archNumber >= 7) {
hasARMv7 = 1;
}
else if (archNumber == 6) {
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv6;
}
else
{
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv5TE;
}
}
else{
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv5TE;
}
/* Unfortunately, it seems that certain ARMv6-based CPUs
* report an incorrect architecture number of 7!
*
* See http://code.google.com/p/android/issues/detail?id=10812
*
* We try to correct this by looking at the 'elf_format'
* field reported by the 'Processor' field, which is of the
* form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for
* an ARMv6-one.
*/
if (hasARMv7) {
char* cpuProc = extract_cpuinfo_field(cpuinfo, cpuinfo_len,
"Processor");
if (cpuProc != NULL) {
D("found cpuProc = '%s'\n", cpuProc);
if (has_list_item(cpuProc, "(v6l)")) {
D("CPU processor and architecture mismatch!!\n");
hasARMv7 = 0;
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv6;
}
free(cpuProc);
}
}
if (hasARMv7) {
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv7;
}
/* The LDREX / STREX instructions are available from ARMv6 */
if (archNumber >= 6) {
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_LDREX_STREX;
}
free(cpuArch);
}
/* Extract the list of CPU features from 'Features' field */
char* cpuFeatures = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "Features");
if (cpuFeatures != NULL) {
D("found cpuFeatures = '%s'\n", cpuFeatures);
if (has_list_item(cpuFeatures, "vfpv3"))
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
else if (has_list_item(cpuFeatures, "vfpv3d16"))
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
if (has_list_item(cpuFeatures, "neon")) {
/* Note: Certain kernels only report neon but not vfpv3
* in their features list. However, ARM mandates
* that if Neon is implemented, so must be VFPv3
* so always set the flag.
*/
g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON |
ANDROID_CPU_ARM_FEATURE_VFPv3;
}
if (has_list_item(cpuFeatures, "vfp")){
g_cpuFeatures |=ANDROID_CPU_ARM_FEATURE_VFP;
}
free(cpuFeatures);
}
}
#endif /* __arm__ */
#ifdef __i386__
g_cpuFamily = ANDROID_CPU_FAMILY_X86;
#endif
}