63 lines
2.3 KiB
C
63 lines
2.3 KiB
C
/* Calcite, src/kernel/paging.h
|
|
* Copyright 2025-2026 Benji Dial
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <stdint.h>
|
|
|
|
extern uint64_t kernel_p3_physical_address;
|
|
|
|
//kernel physical and virtual bases are passed so that we can compute the
|
|
//physical addresses of the kernel's statically allocated paging structures.
|
|
void init_paging(uint64_t kernel_physical_base, void *kernel_virtual_base);
|
|
|
|
//base and length should be page-aligned
|
|
void mark_physical_memory_free(uint64_t base, uint64_t length);
|
|
|
|
//maps one page. physical and virtual bases should be page-aligned.
|
|
//virtual address should be within kernel range.
|
|
void map_in_kernel_page_table(
|
|
uint64_t physical_base, void *virtual_base, int writable, int executable);
|
|
|
|
//virtual base should be page-aligned and within kernel range.
|
|
void create_kernel_guard_page(void *virtual_base);
|
|
|
|
//unmaps one page. base should be page-aligned and within kernel range.
|
|
void unmap_kernel_page(void *virtual_base);
|
|
|
|
//unmaps one page, and frees the corresponding physical page.
|
|
//base should be page-aligned and within kernel range.
|
|
void unmap_and_free_kernel_page(void *virtual_base);
|
|
|
|
//returns a region of contiguous pages in kernel virtual memory where nothing
|
|
//is mapped. length should be page-aligned.
|
|
void *find_free_kernel_region(uint64_t length);
|
|
|
|
uint64_t take_free_physical_page();
|
|
|
|
//implemented in paging.asm. the continuation should be noreturn.
|
|
[[noreturn]] void switch_to_kernel_page_tables(void (*continuation)());
|
|
|
|
//returns the top
|
|
void *create_syscall_stack();
|
|
void destroy_syscall_stack(void *stack_top);
|
|
|
|
//return value in bytes
|
|
uint64_t count_free_pram();
|
|
|
|
//return value in bytes
|
|
uint64_t count_free_kernel_vram();
|