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Kernel: Unallocate RSDT after we are done with it

This commit is contained in:
Bananymous 2023-01-12 13:45:01 +02:00
parent 087d14fbb7
commit 301ad89783
3 changed files with 34 additions and 3 deletions
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5
kernel/arch/i386/APIC.cpp
View File

@ -210,8 +210,8 @@ namespace APIC
static void ParseMADT(RSDPDescriptor* rsdp)
{
RSDT* root = (RSDT*)(rsdp->revision == 2 ? ((RSDPDescriptor20*)rsdp)->xsdt_address : rsdp->rsdt_address);
MMU::Get().AllocatePage((uint32_t)root);
RSDT* const root = (RSDT*)(rsdp->revision == 2 ? ((RSDPDescriptor20*)rsdp)->xsdt_address : rsdp->rsdt_address);
MMU::Get().AllocatePage((uintptr_t)root);
uint32_t sdt_entry_count = (root->header.length - sizeof(root->header)) / (rsdp->revision == 2 ? 8 : 4);
for (uint32_t i = 0; i < sdt_entry_count; i++)
@ -305,6 +305,7 @@ namespace APIC
}
}
}
MMU::Get().UnAllocatePage((uintptr_t)root);
}
static uint32_t ReadLocalAPIC(uint32_t offset)

27
kernel/arch/i386/MMU.cpp
View File

@ -96,3 +96,30 @@ void MMU::AllocateRange(uintptr_t address, ptrdiff_t size)
for (uintptr_t page = s_page; page <= e_page; page += PAGE_SIZE)
AllocatePage(page);
}
void MMU::UnAllocatePage(uintptr_t address)
{
uint32_t pdpte = (address & 0xC0000000) >> 30;
uint32_t pde = (address & 0x3FE00000) >> 21;
uint32_t pte = (address & 0x001FF000) >> 12;
uint64_t* page_directory = (uint64_t*)(m_page_descriptor_pointer_table[pdpte] & PAGE_MASK);
ASSERT(page_directory[pde] & PRESENT);
uint64_t* page_table = (uint64_t*)(page_directory[pde] & PAGE_MASK);
ASSERT(page_table[pte] & PRESENT);
page_table[pte] = 0;
// TODO: Unallocate the page table if this was the only allocated page
asm volatile("invlpg (%0)" :: "r"(address & PAGE_MASK) : "memory");
}
void MMU::UnAllocateRange(uintptr_t address, ptrdiff_t size)
{
uintptr_t s_page = address & PAGE_MASK;
uintptr_t e_page = (address + size - 1) & PAGE_MASK;
for (uintptr_t page = s_page; page <= e_page; page += PAGE_SIZE)
UnAllocatePage(page);
}

3
kernel/include/kernel/MMU.h
View File

@ -12,6 +12,9 @@ public:
void AllocatePage(uintptr_t);
void AllocateRange(uintptr_t, ptrdiff_t);
void UnAllocatePage(uintptr_t);
void UnAllocateRange(uintptr_t, ptrdiff_t);
private:
MMU();