| ␉␉//␊ |
| ␉␉UInt8 index = 0;␊ |
| ␉␉EFI_UINT16 PMTimerValue = 0;␊ |
| ␉␉EFI_UINT32 randomValue, tempValue, cpuTick;␊ |
| ␉␉EFI_UINT32 ecx, esi, edi = 0;␊ |
| ␉␉EFI_UINT32 rcx, rdx, rsi, rdi;␊ |
| ␉␉EFI_UINT32 randomValue = 0, cpuTick = 0;␊ |
| ␉␉EFI_UINT32 ecx = 0, edx = 0, esi = 0, edi = 0;␊ |
| ␊ |
| ␉␉randomValue = tempValue = ecx = esi = edi = 0;␉␉␉␉␉// xor␉␉%ecx,␉%ecx␊ |
| ␉␉cpuTick = rcx = rdx = rsi = rdi = 0;␊ |
| ␊ |
| ␉␉// LEAF_1 - Feature Information (Function 01h).␊ |
| ␉␉if (Platform.CPU.CPUID[CPUID_1][2] & 0x40000000)␉␉␉␉// Checking ecx:bit-30␊ |
| ␉␉{␊ |
|
| ␉␉␉//␊ |
| ␉␉␉EFI_UINT32 seedBuffer[16] = {0};␊ |
| ␉␉␉//␊ |
| ␉␉␉// Main loop to get 16 qwords (four bytes each).␊ |
| ␉␉␉// Main loop to get 16 dwords (four bytes each).␊ |
| ␉␉␉//␊ |
| ␉␉␉for (index = 0; index < 16; index++)␉␉␉␉␉// 0x17e12:␊ |
| ␉␉␉{␊ |
| ␉␉␉␉randomValue = computeRand();␉␉␉␉␉// callq␉0x18e20␊ |
| ␉␉␉␉cpuTick = getCPUTick();␉␉␉␉␉␉// callq␉0x121a7␊ |
| ␉␉␉␉cpuTick = (EFI_UINT32) getCPUTick();␉␉// callq␉0x121a7␊ |
| ␉␉␉␉randomValue = (randomValue ^ cpuTick);␉␉␉␉// xor␉␉%rdi,␉%rax␊ |
| ␉␉␉␉seedBuffer[index] = randomValue;␉␉␉␉// mov␉␉%rax,(%r15,%rsi,8)␊ |
| ␉␉␉}␉␉␉␉␉␉␉␉␉// jb␉␉0x17e12␊ |
|
| ␉␉␉//␊ |
| ␉␉␉do␉␉␉␉␉␉␉␉␉// 0x17e55:␊ |
| ␉␉␉{␊ |
| ␉␉␉␉//␊ |
| ␉␉␉␉// FIXME: PM Timer is usually @ 0x408, but its position is relocatable␊ |
| ␉␉␉␉// via PCI-to-ISA bridge. The location is reported in ACPI FADT,␊ |
| ␉␉␉␉// PM Timer Block address - zenith432␊ |
| ␉␉␉␉//␊ |
| ␉␉␉␉PMTimerValue = inw(0x408);␉␉␉␉␉// in␉␉(%dx),␉%ax␊ |
| ␉␉␉␉esi = PMTimerValue;␉␉␉␉␉␉// movzwl␉%ax,␉%esi␊ |
| ␊ |
|
| ␉␉␉␉␉continue;␉␉␉␉␉␉// jb␉␉0x17e55␉␉(retry)␊ |
| ␉␉␉␉}␊ |
| ␊ |
| ␉␉␉␉cpuTick = getCPUTick();␉␉␉␉␉␉// callq␉0x121a7␊ |
| //␉␉␉␉printf("value: 0x%llx\n", getCPUTick());␊ |
| ␉␉␉␉rcx = (cpuTick >> 8);␉␉␉␉␉␉// mov␉␉%rax,␉%rcx␊ |
| ␉␉␉␉cpuTick = (EFI_UINT32) getCPUTick();␉␉// callq␉0x121a7␊ |
| //␉␉␉␉printf("value: 0x%x\n", getCPUTick());␊ |
| ␉␉␉␉ecx = (cpuTick >> 8);␉␉␉␉␉␉// mov␉␉%rax,␉%rcx␊ |
| ␉␉␉␉// shr␉␉$0x8,␉%rcx␊ |
| ␉␉␉␉rdx = (cpuTick >> 10);␉␉␉␉␉␉// mov␉␉%rax,␉%rdx␊ |
| ␉␉␉␉edx = (cpuTick >> 0x10);␉␉␉␉␉// mov␉␉%rax,␉%rdx␊ |
| ␉␉␉␉// shr␉␉$0x10,␉%rdx␊ |
| ␉␉␉␉rdi = rsi;␉␉␉␉␉␉␉// mov␉␉%rsi,␉%rdi␊ |
| ␉␉␉␉rdi = (rdi ^ cpuTick);␉␉␉␉␉␉// xor␉␉%rax,␉%rdi␊ |
| ␉␉␉␉rdi = (rdi ^ rcx);␉␉␉␉␉␉// xor␉␉%rcx,␉%rdi␊ |
| ␉␉␉␉rdi = (rdi ^ rdx);␉␉␉␉␉␉// xor␉␉%rdx,␉%rdi␊ |
| ␉␉␉␉edi = esi;␉␉␉␉␉␉␉// mov␉␉%rsi,␉%rdi␊ |
| ␉␉␉␉edi = (edi ^ cpuTick);␉␉␉␉␉␉// xor␉␉%rax,␉%rdi␊ |
| ␉␉␉␉edi = (edi ^ ecx);␉␉␉␉␉␉// xor␉␉%rcx,␉%rdi␊ |
| ␉␉␉␉edi = (edi ^ edx);␉␉␉␉␉␉// xor␉␉%rdx,␉%rdi␊ |
| ␊ |
| ␉␉␉␉seedBuffer[index] = (rdi & 0xff);␉␉␉␉// mov␉␉%dil,␉(%r15,%r12,1)␊ |
| ␉␉␉␉seedBuffer[index] = (edi & 0xff);␉␉␉␉// mov␉␉%dil,␉(%r15,%r12,1)␊ |
| ␊ |
| ␉␉␉␉edi = (edi & 0x2f);␉␉␉␉␉␉// and␉␉$0x2f,␉%edi␊ |
| ␉␉␉␉edi = (edi + esi);␉␉␉␉␉␉// add␉␉%esi,␉%edi␊ |
