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Kernel: Remove map_for_kernel() in MemoryManager

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We don't need to have this method anymore. It was a hack that was used
in many components in the system but currently we use better methods to
create virtual memory mappings. To prevent any further use of this
method it's best to just remove it completely.

Also, the APIC code is disabled for now since it doesn't help booting
the system, and is broken since it relies on identity mapping to exist
in the first 1MB. Any call to the APIC code will result in assertion
failed.

In addition to that, the name of the method which is responsible to
create an identity mapping between 1MB to 2MB was changed, to be more
precise about its purpose.
This commit is contained in:
Liav A 2020-01-21 04:41:02 +02:00 • committed by Andreas Kling
parent 60c32f44dd
commit 200a5b0649
4 changed files with 7 additions and 22 deletions
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17
Kernel/VM/MemoryManager.cpp
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@ -55,7 +55,7 @@ MemoryManager::MemoryManager()
asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3()));
setup_low_1mb();
setup_low_identity_mapping();
protect_kernel_image();
}
@ -83,7 +83,7 @@ void MemoryManager::protect_kernel_image()
}
}
void MemoryManager::setup_low_1mb()
void MemoryManager::setup_low_identity_mapping()
{
m_low_page_table = allocate_user_physical_page(ShouldZeroFill::Yes);
@ -101,7 +101,7 @@ void MemoryManager::setup_low_1mb()
if (g_cpu_supports_nx)
pde_zero.set_execute_disabled(true);
for (uintptr_t offset = 0; offset < (2 * MB); offset += PAGE_SIZE) {
for (uintptr_t offset = (1 * MB); offset < (2 * MB); offset += PAGE_SIZE) {
auto& page_table_page = m_low_page_table;
auto& pte = quickmap_pt(page_table_page->paddr())[offset / PAGE_SIZE];
pte.set_physical_page_base(offset);
@ -532,17 +532,6 @@ PageTableEntry* MemoryManager::quickmap_pt(PhysicalAddress pt_paddr)
return (PageTableEntry*)0xffe08000;
}
void MemoryManager::map_for_kernel(VirtualAddress vaddr, PhysicalAddress paddr, bool cache_disabled)
{
auto& pte = ensure_pte(kernel_page_directory(), vaddr);
pte.set_physical_page_base(paddr.get());
pte.set_present(true);
pte.set_writable(true);
pte.set_user_allowed(false);
pte.set_cache_disabled(cache_disabled);
flush_tlb(vaddr);
}
u8* MemoryManager::quickmap_page(PhysicalPage& physical_page)
{
ASSERT_INTERRUPTS_DISABLED();