From b1a912a8a6ff472a49b2e0a09cfd433adfc2cb24 Mon Sep 17 00:00:00 2001 From: Benji Dial Date: Sat, 18 May 2024 21:53:38 -0400 Subject: reorganization, cross compiler --- kernel/paging.cpp | 145 ------------------------------------------------------ 1 file changed, 145 deletions(-) delete mode 100644 kernel/paging.cpp (limited to 'kernel/paging.cpp') diff --git a/kernel/paging.cpp b/kernel/paging.cpp deleted file mode 100644 index d8869fc..0000000 --- a/kernel/paging.cpp +++ /dev/null @@ -1,145 +0,0 @@ -#include -#include - -//see also ../documentation/memory.txt - -extern "C" { - uint64_t __kernel_p4_paddr; -} - -namespace hilbert::kernel::paging { - - static constexpr uint64_t kernel_vram_start = 0xffffffffc0000000; - static constexpr uint64_t kernel_vram_end = 0xffffffffffe00000; - static constexpr uint64_t kernel_vram_pages = - (kernel_vram_end - kernel_vram_start) / 4096; - static constexpr uint64_t syscall_stack_bottom = 0xfffffffffff01000; - static constexpr uint64_t syscall_stack_top = 0xfffffffffffff000; - static constexpr uint64_t interrupt_stack_bottom = 0xffffffffffe01000; - static constexpr uint64_t interrupt_stack_top = 0xffffffffffeff000; - - static constexpr uint64_t pram_pages = 1 << 23; - static uint64_t pram_usage_bitmap[pram_pages / 64]; - - void mark_all_pram_used() { - utility::mark_bitmap_region_one(pram_usage_bitmap, 0, pram_pages); - } - - void mark_pram_region_free(uint64_t start_addr, uint64_t end_addr) { - utility::mark_bitmap_region_zero( - pram_usage_bitmap, start_addr / 4096, - utility::min(end_addr / 4096, pram_pages)); - } - - [[gnu::aligned(4096)]] uint64_t kernel_p4[512]; - [[gnu::aligned(4096)]] uint64_t kernel_p3[512]; - [[gnu::aligned(4096)]] uint64_t kernel_p2[512]; - [[gnu::aligned(4096)]] uint64_t kernel_p1s[512 * 512]; - - uint64_t kernel_p4e; - - uint64_t encode_pte(uint64_t addr, bool user, bool write, bool execute) { - return (addr & 0x0000ffffffffffff) | (execute ? 0 : (1ULL << 63)) - | (user << 2) | (write << 1) | 1; - } - - void init_kernel_page_tables(uint64_t kernel_offset) { - __kernel_p4_paddr = (uint64_t)kernel_p4 - kernel_offset; - for (int i = 0; i < 511; ++i) - kernel_p4[i] = 0; - kernel_p4e = encode_pte( - (uint64_t)kernel_p3 - kernel_offset, false, true, true); - kernel_p4[511] = kernel_p4e; - for (int i = 0; i < 511; ++i) - kernel_p3[i] = 0; - kernel_p3[511] = encode_pte( - (uint64_t)kernel_p2 - kernel_offset, false, true, true); - for (int i = 0; i < 512; ++i) - kernel_p2[i] = encode_pte( - (uint64_t)kernel_p1s + 4096 * i - kernel_offset, false, true, true); - for (int i = 0; i < 512 * 512; ++i) - kernel_p1s[i] = 0; - } - - void map_kernel_page( - uint64_t paddr, uint64_t vaddr, bool write, bool execute) { - uint64_t i = (vaddr - kernel_vram_start) / 4096; - kernel_p1s[i] = encode_pte(paddr, false, write, execute); - } - - void unmap_kernel_page(uint64_t vaddr) { - uint64_t i = (vaddr - kernel_vram_start) / 4096; - kernel_p1s[i] = 0; - asm volatile ( - "mov %%cr3, %%rax\nmov %%rax, %%cr3" ::: "%rax" - ); - } - - uint64_t take_pram_page() { - for (uint64_t i = 0; i < pram_pages / 64; ++i) - if (~pram_usage_bitmap[i] != 0) - for (int j = 0; j < 64; ++j) - if (~pram_usage_bitmap[i] & (1ULL << j)) { - pram_usage_bitmap[i] |= (1ULL << j); - return 4096 * (i * 64 + j); - } - //TODO: handle error - return 0; - } - - void map_kernel_stacks() { - for (uint64_t vaddr = syscall_stack_bottom; - vaddr < syscall_stack_top; vaddr += 4096) - map_kernel_page(take_pram_page(), vaddr, true, false); - for (uint64_t vaddr = interrupt_stack_bottom; - vaddr < interrupt_stack_top; vaddr += 4096) - map_kernel_page(take_pram_page(), vaddr, true, false); - } - - uint64_t find_unmapped_vram_region(uint64_t page_count) { - uint64_t start = 0; - uint64_t len = 0; - for (uint64_t i = 0; i < kernel_vram_pages; ++i) - if (kernel_p1s[i] == 0) { - ++len; - if (len == page_count) - return start * 4096 + kernel_vram_start; - } - else { - start = i + 1; - len = 0; - } - //TODO: handle error - return 0; - } - - void *map_new_kernel_pages(uint64_t count) { - uint64_t vaddr = find_unmapped_vram_region(count); - for (uint64_t i = 0; i < count; ++i) - map_kernel_page(take_pram_page(), vaddr + i * 4096, true, false); - return (void *)vaddr; - } - - void map_new_kernel_page(uint64_t &vaddr_out, uint64_t &paddr_out) { - vaddr_out = find_unmapped_vram_region(1); - paddr_out = take_pram_page(); - map_kernel_page(paddr_out, vaddr_out, true, false); - } - - uint64_t get_used_vram_page_count() { - uint64_t count = 0; - for (uint64_t i = 0; i < kernel_vram_pages; ++i) - if (kernel_p1s[i] != 0) - ++count; - return count; - } - - uint64_t get_free_pram_page_count() { - uint64_t used_count = 0; - for (uint64_t i = 0; i < pram_pages / 64; ++i) - for (uint64_t j = 0; j < 64; ++j) - used_count += (pram_usage_bitmap[i] >> j) & 1; - return pram_pages - used_count; - } - -} -- cgit v1.2.3