Kernel/core/random.cpp
2024-05-01 05:14:44 +03:00

117 lines
2.6 KiB
C++

/*
This file is part of Fennix Kernel.
Fennix Kernel is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of
the License, or (at your option) any later version.
Fennix Kernel is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
#include <rand.hpp>
#include <cpu.hpp>
namespace Random
{
uint64_t Seed = 0xdeadbeef;
bool RDRANDFlag, RDSEEDFlag;
__constructor void InitRandomSeed()
{
if (strcmp(CPU::Hypervisor(), x86_CPUID_VENDOR_TCG) != 0)
{
if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_AMD) == 0)
{
CPU::x86::AMD::CPUID0x00000007_ECX_0 cpuid;
RDSEEDFlag = cpuid.EBX.RDSEED;
}
else if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_INTEL) == 0)
{
CPU::x86::Intel::CPUID0x00000007_0 cpuid;
RDSEEDFlag = cpuid.EBX.RDSEED;
}
}
else
RDSEEDFlag = false;
if (strcmp(CPU::Hypervisor(), x86_CPUID_VENDOR_TCG) != 0)
{
if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_AMD) == 0)
{
CPU::x86::AMD::CPUID0x00000001 cpuid;
RDRANDFlag = cpuid.ECX.RDRAND;
}
else if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_INTEL) == 0)
{
CPU::x86::Intel::CPUID0x00000001 cpuid;
RDRANDFlag = cpuid.ECX.RDRAND;
}
}
else
RDRANDFlag = false;
if (RDSEEDFlag)
fixme("RDSEED is not implemented yet!");
}
uint16_t rand16()
{
#if defined(a86)
if (RDRANDFlag)
{
uint16_t RDRANDValue = 0;
asmv("1: rdrand %0; jnc 1b"
: "=r"(RDRANDValue));
return RDRANDValue;
}
Seed = Seed * 1103515245 + 12345;
return (uint16_t)(Seed / 65536) % __UINT16_MAX__;
#endif
return 0;
}
uint32_t rand32()
{
#if defined(a86)
if (RDRANDFlag)
{
uint32_t RDRANDValue = 0;
asmv("1: rdrand %0; jnc 1b"
: "=r"(RDRANDValue));
return RDRANDValue;
}
Seed = Seed * 1103515245 + 12345;
return (uint32_t)(Seed / 65536) % __UINT32_MAX__;
#endif
return 0;
}
uint64_t rand64()
{
#if defined(a86)
if (RDRANDFlag)
{
uintptr_t RDRANDValue = 0;
asmv("1: rdrand %0; jnc 1b"
: "=r"(RDRANDValue));
return RDRANDValue;
}
Seed = Seed * 1103515245 + 12345;
return (uint64_t)(Seed / 65536) % __UINT64_MAX__;
#endif
return 0;
}
void ChangeSeed(uint64_t CustomSeed) { Seed = CustomSeed; }
}