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Kernel: Move Multiboot memory map parsing to its own function

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This commit is contained in:
Andreas Kling 2020-01-17 21:03:52 +01:00
parent ba8275a48e
commit 7e6f0efe7c
2 changed files with 75 additions and 74 deletions
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148
Kernel/VM/MemoryManager.cpp
View file

@ -68,22 +68,88 @@ void MemoryManager::initialize_paging()
}
#endif
// Basic virtual memory map:
// 0 -> 4 KB Null page (so nullptr dereferences crash!)
// 4 KB -> 8 MB Identity mapped.
// 8 MB -> 3 GB Available to userspace.
// 3GB -> 4 GB Kernel-only virtual address space (>0xc0000000)
m_quickmap_addr = VirtualAddress(0xffe00000);
#ifdef MM_DEBUG
dbgprintf("MM: Quickmap will use %p\n", m_quickmap_addr.get());
#endif
parse_memory_map();
#ifdef MM_DEBUG
dbgprintf("MM: Installing page directory\n");
#endif
// Turn on CR4.PAE
asm volatile(
"mov %cr4, %eax\n"
"orl $0x20, %eax\n"
"mov %eax, %cr4\n");
if (g_cpu_supports_pge) {
// Turn on CR4.PGE so the CPU will respect the G bit in page tables.
asm volatile(
"mov %cr4, %eax\n"
"orl $0x80, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: PGE support enabled\n");
} else {
kprintf("x86: PGE support not detected\n");
}
if (g_cpu_supports_smep) {
// Turn on CR4.SMEP
asm volatile(
"mov %cr4, %eax\n"
"orl $0x100000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMEP support enabled\n");
} else {
kprintf("x86: SMEP support not detected\n");
}
if (g_cpu_supports_smap) {
// Turn on CR4.SMAP
kprintf("x86: Enabling SMAP\n");
asm volatile(
"mov %cr4, %eax\n"
"orl $0x200000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMAP support enabled\n");
} else {
kprintf("x86: SMAP support not detected\n");
}
if (g_cpu_supports_nx) {
// Turn on IA32_EFER.NXE
asm volatile(
"movl $0xc0000080, %ecx\n"
"rdmsr\n"
"orl $0x800, %eax\n"
"wrmsr\n");
kprintf("x86: NX support enabled\n");
} else {
kprintf("x86: NX support not detected\n");
}
asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3()));
asm volatile(
"movl %%cr0, %%eax\n"
"orl $0x80010001, %%eax\n"
"movl %%eax, %%cr0\n" ::
: "%eax", "memory");
#ifdef MM_DEBUG
dbgprintf("MM: Paging initialized.\n");
#endif
}
void MemoryManager::parse_memory_map()
{
RefPtr<PhysicalRegion> region;
bool region_is_super = false;
auto* mmap = (multiboot_memory_map_t*)(0xc0000000 + multiboot_info_ptr->mmap_addr);
for (; (unsigned long)mmap < (0xc0000000 + multiboot_info_ptr->mmap_addr) + (multiboot_info_ptr->mmap_length); mmap = (multiboot_memory_map_t*)((unsigned long)mmap + mmap->size + sizeof(mmap->size))) {
auto* mmap = (multiboot_memory_map_t*)(low_physical_to_virtual(multiboot_info_ptr->mmap_addr));
for (; (unsigned long)mmap < (low_physical_to_virtual(multiboot_info_ptr->mmap_addr)) + (multiboot_info_ptr->mmap_length); mmap = (multiboot_memory_map_t*)((unsigned long)mmap + mmap->size + sizeof(mmap->size))) {
kprintf("MM: Multiboot mmap: base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
(u32)(mmap->addr >> 32),
(u32)(mmap->addr & 0xffffffff),
@ -153,72 +219,6 @@ void MemoryManager::initialize_paging()
for (auto& region : m_user_physical_regions)
m_user_physical_pages += region.finalize_capacity();
#ifdef MM_DEBUG
dbgprintf("MM: Installing page directory\n");
#endif
// Turn on CR4.PAE
asm volatile(
"mov %cr4, %eax\n"
"orl $0x20, %eax\n"
"mov %eax, %cr4\n");
if (g_cpu_supports_pge) {
// Turn on CR4.PGE so the CPU will respect the G bit in page tables.
asm volatile(
"mov %cr4, %eax\n"
"orl $0x80, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: PGE support enabled\n");
} else {
kprintf("x86: PGE support not detected\n");
}
if (g_cpu_supports_smep) {
// Turn on CR4.SMEP
asm volatile(
"mov %cr4, %eax\n"
"orl $0x100000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMEP support enabled\n");
} else {
kprintf("x86: SMEP support not detected\n");
}
if (g_cpu_supports_smap) {
// Turn on CR4.SMAP
kprintf("x86: Enabling SMAP\n");
asm volatile(
"mov %cr4, %eax\n"
"orl $0x200000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMAP support enabled\n");
} else {
kprintf("x86: SMAP support not detected\n");
}
if (g_cpu_supports_nx) {
// Turn on IA32_EFER.NXE
asm volatile(
"movl $0xc0000080, %ecx\n"
"rdmsr\n"
"orl $0x800, %eax\n"
"wrmsr\n");
kprintf("x86: NX support enabled\n");
} else {
kprintf("x86: NX support not detected\n");
}
asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3()));
asm volatile(
"movl %%cr0, %%eax\n"
"orl $0x80010001, %%eax\n"
"movl %%eax, %%cr0\n" ::
: "%eax", "memory");
#ifdef MM_DEBUG
dbgprintf("MM: Paging initialized.\n");
#endif
}
PageTableEntry& MemoryManager::ensure_pte(PageDirectory& page_directory, VirtualAddress vaddr)

1
Kernel/VM/MemoryManager.h
View file

@ -122,6 +122,7 @@ private:
void detect_cpu_features();
void initialize_paging();
void parse_memory_map();
void flush_entire_tlb();
void flush_tlb(VirtualAddress);