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fix(vmm): make MMU bring-up and kernel mappings reliable

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This commit is contained in:
karina
2026-04-26 23:41:57 +04:00
parent b56b55e4b3
commit 5d010f7fb2
8 changed files with 167 additions and 13 deletions
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Kernel/Source/VM/VMM.c
+30 -8
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@@ -4,6 +4,7 @@
#include <Arch/CPU.h>
#include <OS/Panic.h>
#include "../Common/bootinfo.h"
#include "OS/Log.h"
static const UInt64 kPTEAddressMask = 0x0000FFFFFFFFF000ULL;
static inline Address GetPTEAddress(UInt64 entry) { return entry & kPTEAddressMask; }
@@ -18,6 +19,9 @@ static Boolean isInitialized = false;
Address* gVMKernelL0Table = nullptr;
Address gVMKernelL0Physical = 0;
extern char _kernelStart[];
extern char _kernelEnd[];
static Address* GetVirtualTable(Address phys) {
if (isInitialized) return (Address*)VMPhysToHHDM(phys);
return (Address*)phys;
@@ -92,7 +96,7 @@ Address* VMMMapPage(Address* l0Table, Address phys, Address virt, UInt64 flags)
if (!l3Virt) return nullptr;
l3Virt[l3Index] = phys | flags | kPTEPage | kPTEAccessFlag | kPTEValid;
CPUInvalidateTLB(virt);
if (isInitialized) CPUInvalidateTLB(virt);
return l3Virt;
}
@@ -138,7 +142,9 @@ void VMMInitialize(VMBootMemoryMap* bootMap, Bootinfo* info) {
gVMKernelL0Physical = (Address)PMMAllocatePage();
gVMKernelL0Table = (Address*)gVMKernelL0Physical;
if (!gVMKernelL0Physical) OSPanic("Failed to allocate kernel L0 table");
MemorySet(gVMKernelL0Table, 0, kVMPageSize);
OSLog("Mapping RAM.. Can take a while\n");
Size totalRAM = bootMap->totalRAM.size;
Size ramEnd = bootMap->totalRAM.base + totalRAM;
for (Address phys = bootMap->totalRAM.base; phys < ramEnd; phys += kVMPageSize) {
@@ -148,14 +154,25 @@ void VMMInitialize(VMBootMemoryMap* bootMap, Bootinfo* info) {
kPTENormalMem | kPTEAccessRW | kPTEPrivNX | kPTEUserNX
);
}
OSLog("RAM mapped\n");
Size pmmBitmapSize = (bootMap->totalRAM.size / kVMPageSize) / 8;
Size kernelSize = ((Address)_kernelEnd - (Address)_kernelStart) + pmmBitmapSize;
kernelSize = (kernelSize + kVMPageSize - 1) & ~(kVMPageSize - 1);
Address kernelPhysStart = 0x40100000; // TODO: hardcode is awful
Address kernelPhysStart = (Address)info->kernelInfo.kernelAddress;
Size kernelSize = info->kernelInfo.kernelSize;
for (Address offset = 0; offset < kernelSize; offset += kVMPageSize) {
Address phys = kernelPhysStart + offset;
Address virt = kVMKernelVMA + offset;
Address virt = (Address)_kernelStart + offset;
VMMMapPage(gVMKernelL0Table, phys, virt, kPTENormalMem | kPTEAccessRW);
}
OSLog("Kernel mapped to HHDM\n");
for (Address offset = 0; offset < kernelSize; offset += kVMPageSize) {
VMMMapPage(gVMKernelL0Table, kernelPhysStart + offset, kernelPhysStart + offset, kPTENormalMem | kPTEAccessRW);
}
OSLog("Kernel Identity mapped\n");
Address fbPhys = (Address)info->framebuffer.base;
Size fbSize = info->framebuffer.baseSize;
@@ -166,18 +183,23 @@ void VMMInitialize(VMBootMemoryMap* bootMap, Bootinfo* info) {
kPTEDeviceMem | kPTEAccessRW | kPTEUserNX | kPTEPrivNX
);
}
OSLog("Framebuffer mapped\n");
Address UARTPhys = bootMap->UART.base;
if (!UARTPhys) UARTPhys = 0x09000000;
VMMMapPage(
gVMKernelL0Table, UARTPhys, VMPhysToHHDM(UARTPhys),
kPTEDeviceMem | kPTEAccessRW | kPTEUserNX | kPTEPrivNX
);
VMMMapPage(
gVMKernelL0Table, UARTPhys, UARTPhys,
kPTEDeviceMem | kPTEAccessRW | kPTEUserNX | kPTEPrivNX
);
OSLog("UART mapped\n");
for (Address offset = 0; offset < kernelSize; offset += kVMPageSize) {
VMMMapPage(gVMKernelL0Table, kernelPhysStart + offset, kernelPhysStart + offset, kPTENormalMem | kPTEAccessRW);
}
info->framebuffer.base = (BIUInt32*)kVMFbVirtBase;;
OSLog("Enabling MMU...\n");
CPUEnableMMU(gVMKernelL0Physical);
isInitialized = true;
}