banan-os/kernel/arch/i386/CPUID.cpp

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#include <kernel/CPUID.h>
namespace CPUID
{
void get_cpuid(uint32_t code, uint32_t* out)
{
asm volatile("cpuid" : "=a"(out[0]), "=b"(out[1]), "=c"(out[2]), "=d"(out[3]) : "a"(code));
}
void get_cpuid_string(uint32_t code, uint32_t* out)
{
asm volatile ("cpuid": "=a"(out[0]), "=b"(out[0]), "=d"(out[1]), "=c"(out[2]) : "a"(code));
}
bool IsAvailable()
{
uint32_t res;
asm volatile(
"pushfl;"
"pushfl;"
"popl %0;"
"xorl %1, %0;"
"pushl %0;"
"popfl;"
"pushfl;"
"popl %0;"
"popfl;"
: "=r"(res)
: "i" (0x00200000));
return res != 0;
}
const char* GetVendor()
{
static char vendor[13] {};
get_cpuid_string(0x00, (uint32_t*)vendor);
vendor[12] = '\0';
return vendor;
}
void GetFeatures(uint32_t& ecx, uint32_t& edx)
{
uint32_t buffer[4] {};
get_cpuid(0x01, buffer);
ecx = buffer[2];
edx = buffer[3];
}
bool Is64Bit()
{
if (!IsAvailable())
return false;
uint32_t buffer[4] {};
get_cpuid(0x80000000, buffer);
if (buffer[0] < 0x80000001)
return false;
get_cpuid(0x80000001, buffer);
return buffer[3] & (1 << 29);
}
}