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add rdrand support

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If available, HermitCore supports rdrand to generate random number.
LwIP uses this instruction to support DNSSec.
This commit is contained in:
Stefan Lankes 2016-11-20 00:48:22 +01:00
parent d287184bbe
commit da4486d93a
3 changed files with 24 additions and 2 deletions
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21
hermit/arch/x86/include/asm/processor.h
View file

@ -76,6 +76,7 @@ extern "C" {
#define CPU_FEATURE_XSAVE (1 << 26)
#define CPU_FEATURE_OSXSAVE (1 << 27)
#define CPU_FEATURE_AVX (1 << 28)
#define CPU_FEATURE_RDRAND (1 << 30)
#define CPU_FEATURE_HYPERVISOR (1 << 31)
// CPUID.80000001H:EDX feature list
@ -389,6 +390,10 @@ inline static uint32_t has_avx(void) {
return (cpu_info.feature2 & CPU_FEATURE_AVX);
}
inline static uint32_t has_rdrand(void) {
return (cpu_info.feature2 & CPU_FEATURE_RDRAND);
}
inline static uint32_t on_hypervisor(void) {
return (cpu_info.feature2 & CPU_FEATURE_HYPERVISOR);
}
@ -452,6 +457,22 @@ static inline void clts(void)
asm volatile("clts");
}
/** @brief Read a random number
*
* Returns a hardware generated random value.
*/
inline static uint32_t rdrand(void)
{
uint32_t val;
uint8_t rc;
do {
asm volatile("rdrand %0 ; setc %1" : "=r" (val), "=qm" (rc));
} while(rc == 0); // rc == 0: underflow
return val;
}
/** @brief Read out time stamp counter
*
* The rdtsc instruction puts a 64 bit time stamp value

3
hermit/arch/x86/kernel/processor.c
View file

@ -554,7 +554,7 @@ int cpu_detection(void) {
a = b = c = d = 0;
cpuid(1, &a, &b, &cpu_info.feature2, &cpu_info.feature1);
LOG_INFO("CPU features: %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
LOG_INFO("CPU features: %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
has_sse() ? "SSE " : "",
has_sse2() ? "SSE2 " : "",
has_sse3() ? "SSE3 " : "",
@ -562,6 +562,7 @@ int cpu_detection(void) {
has_sse4_2() ? "SSE4.2 " : "",
has_avx() ? "AVX " : "",
has_avx2() ? "AVX2 " : "",
has_rdrand() ? "RDRAND " : "",
has_fma() ? "FMA " : "",
has_movbe() ? "MOVBE " : "",
has_x2apic() ? "X2APIC " : "",

2
hermit/lwip

@ -1 +1 @@
Subproject commit 594aea71498c7c11850186f9b7d85e95ee34ac68
Subproject commit 3dbc272333882dd02029ef9c45bbcb4c59ee7a6d