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mm: Changes

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+ vmm: Rename to "paging"
+ vma: Start implementation
This commit is contained in:
RaphProductions 2025-05-19 07:25:31 +02:00
parent c658f738e4
commit 16246cc167
8 changed files with 125 additions and 51 deletions
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179
kernel/src/mm/vmm.c
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@ -1,179 +0,0 @@
/*
* The Soaplin Kernel
* Copyright (C) 2025 The SILD Project
*
* vmm.c - Virtual memory manager
*/
#include <stdbool.h>
#include <stddef.h>
#include <arch/cpu.h>
#include <boot/limine.h>
#include <exec/elf.h>
#include <lib/log.h>
#include <mm/memop.h>
#include <mm/pmm.h>
#include <mm/vmm.h>
#include <stdint.h>
pagemap_t vmm_kernel_pm = NULL;
pagemap_t vmm_current_pm = NULL;
void vmm_init() {
#if !defined(__x86_64__)
fatal("vmm: not implemented\n");
hcf();
#endif
// Our objective here is to recreate the
// kernel page map that Limine provide us
vmm_kernel_pm = vmm_alloc_pm();
uint64_t kvaddr = limine_get_kernel_vaddr();
uint64_t kpaddr = limine_get_kernel_paddr();
char *elf_addr = (char *)limine_get_kernel_ehdr_addr();
Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elf_addr;
for (uint16_t i = 0; i < ehdr->e_phnum; i++) {
Elf64_Phdr *cur_phdr = (Elf64_Phdr*)(elf_addr + ehdr->e_phoff + (i * ehdr->e_phentsize));
if (cur_phdr->p_type != PT_LOAD)
continue;
uintptr_t phys = (cur_phdr->p_vaddr - kvaddr) + kpaddr;
uint64_t flags = PTE_PRESENT;
if ((cur_phdr->p_flags & PF_X) == 0) {
flags |= PTE_NX;
}
if (cur_phdr->p_flags & PF_W) {
flags |= PTE_WRITE;
}
size_t length = ALIGN_UP(cur_phdr->p_memsz, PMM_PAGE_SIZE);
for (uint64_t i = 0; i < length; i += PMM_PAGE_SIZE) {
vmm_map(vmm_kernel_pm, cur_phdr->p_vaddr + i, phys + i, flags);
}
trace("vmm: Mapped range: %p -> %p (length: %x)\n", phys, cur_phdr->p_vaddr, length);
}
for (uint64_t i = 0; i < 0x100000000; i += PMM_PAGE_SIZE)
vmm_map(vmm_kernel_pm, higher_half(i), i, PTE_PRESENT | PTE_WRITE);
trace("vmm: Mapped range: %p -> %p (length: %x)\n", 0x0, 0xFFFF800000000000, 0x100000000);
vmm_load_pm(vmm_kernel_pm);
trace("vmm: Initialized.\n");
}
void vmm_load_pm(pagemap_t pm) {
if (!pm)
return;
vmm_current_pm = pm;
cpu_load_pm((pagemap_t)physical((uint64_t)pm));
}
pagemap_t vmm_alloc_pm() {
pagemap_t pm = (pagemap_t)higher_half((uint64_t)pmm_alloc_page());
memset((void*)pm, 0, PMM_PAGE_SIZE);
if (vmm_kernel_pm)
{
for (int i = 256; i < 512; i++)
pm[i] = vmm_kernel_pm[i];
}
return pm;
}
void vmm_free_pm(pagemap_t pm) {
if (pm == vmm_kernel_pm)
{
warn("vmm: Who tried to free the kernel's pagemap?!\n");
return;
}
pmm_free_page((void*)pm);
}
static uint64_t *__vmm_get_next_lvl(uint64_t *level, uint64_t entry,
uint64_t flags, bool alloc) {
if (level[entry] & PTE_PRESENT)
return (uint64_t *)higher_half(PTE_GET_ADDR(level[entry]));
if (alloc) {
uint64_t *pml = (uint64_t *)higher_half((uint64_t)pmm_alloc_page());
memset(pml, 0, PMM_PAGE_SIZE);
level[entry] = (uint64_t)physical((uint64_t)pml) | flags;
return pml;
}
return NULL;
}
void vmm_map(pagemap_t pm, uint64_t vaddr, uint64_t paddr, uint64_t flags) {
if (!pm) return;
uint64_t pml4_entry = (vaddr >> 39) & 0x1ff;
uint64_t pml3_entry = (vaddr >> 30) & 0x1ff;
uint64_t pml2_entry = (vaddr >> 21) & 0x1ff;
uint64_t pml1_entry = (vaddr >> 12) & 0x1ff;
uint64_t *pml3 = __vmm_get_next_lvl(pm , pml4_entry, PTE_PRESENT | PTE_WRITE, true);
uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_entry, PTE_PRESENT | PTE_WRITE, true);
uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_entry, PTE_PRESENT | PTE_WRITE, true);
pml1[pml1_entry] = paddr | flags;
}
void vmm_map_user(pagemap_t pm, uint64_t vaddr, uint64_t paddr,
uint64_t flags) {
if (!pm) return;
uint64_t pml4_entry = (vaddr >> 39) & 0x1ff;
uint64_t pml3_entry = (vaddr >> 30) & 0x1ff;
uint64_t pml2_entry = (vaddr >> 21) & 0x1ff;
uint64_t pml1_entry = (vaddr >> 12) & 0x1ff;
uint64_t *pml3 = __vmm_get_next_lvl(pm , pml4_entry, flags, true);
uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_entry, flags, true);
uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_entry, flags, true);
pml1[pml1_entry] = paddr | flags;
}
void vmm_unmap(pagemap_t pm, uint64_t vaddr) {
if (!pm) return;
uint64_t pml4_entry = (vaddr >> 39) & 0x1ff;
uint64_t pml3_entry = (vaddr >> 30) & 0x1ff;
uint64_t pml2_entry = (vaddr >> 21) & 0x1ff;
uint64_t pml1_entry = (vaddr >> 12) & 0x1ff;
uint64_t *pml3 = __vmm_get_next_lvl(pm , pml4_entry, 0, false);
if (!pml3) return;
uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_entry, 0, false);
if (!pml2) return;
uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_entry, 0, false);
if (!pml1) return;
pml1[pml1_entry] = 0;
cpu_invalidate_page(pm, vaddr);
}
void vmm_protect(pagemap_t pm, uint64_t vaddr, uint64_t flags) {
if (!pm) return;
uint64_t pml4_entry = (vaddr >> 39) & 0x1ff;
uint64_t pml3_entry = (vaddr >> 30) & 0x1ff;
uint64_t pml2_entry = (vaddr >> 21) & 0x1ff;
uint64_t pml1_entry = (vaddr >> 12) & 0x1ff;
uint64_t *pml3 = __vmm_get_next_lvl(pm , pml4_entry, 0, false);
if (!pml3) return;
uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_entry, 0, false);
if (!pml2) return;
uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_entry, 0, false);
if (!pml1) return;
uint64_t paddr = pml1[pml1_entry] & PTE_ADDR_MASK;
pml1[pml1_entry] = paddr | flags;
}