From f90c075d5061b3a89316d6bf3d5b190d49049ccd Mon Sep 17 00:00:00 2001 From: Brett Weiland Date: Wed, 24 Mar 2021 15:42:20 -0500 Subject: renamed: kernel/include/acpi.h -> include/acpi.h renamed: kernel/include/libc.h -> include/libc.h renamed: kernel/include/paging.h -> include/paging.h renamed: kernel/include/printf.h -> include/printf.h renamed: kernel/include/serial.h -> include/serial.h renamed: kernel/include/video.h -> include/video.h new file: indigo_os renamed: kernel/libs/acpi.c -> kernel/acpi.c renamed: kernel/libs/drivers/serial.c -> kernel/drivers/serial.c renamed: kernel/libs/drivers/video.c -> kernel/drivers/video.c renamed: kernel/libs/libc.c -> kernel/libc.c renamed: kernel/libs/page.c -> kernel/page.c renamed: kernel/libs/printf.c -> kernel/printf.c renamed: kernel/libs/printf.h -> kernel/printf.h modified: makefile --- src/kernel/page.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 src/kernel/page.c (limited to 'src/kernel/page.c') diff --git a/src/kernel/page.c b/src/kernel/page.c new file mode 100644 index 0000000..6f1dd7c --- /dev/null +++ b/src/kernel/page.c @@ -0,0 +1,157 @@ +#include +#include +#include +#include + +void debug_print_memory() { + struct memory_table *memtable = (struct memory_table *)&_meminfo_loc; + printf(" __________________________________________________________________________\n"); + printf("| type\tstart\t\t\tend\t\t\tsize\t\t |\n"); + printf("|--------------------------------------------------------------------------|\n"); + for(unsigned int i = 0; memtable[i].length > 0; i++) { + printf("| %u %u\t0x%p\t0x%p\t0x%p |\n", memtable[i].type, memtable[i].ACPI, memtable[i].base, (memtable[i].base + memtable[i].length), memtable[i].length); + } + printf("----------------------------------------------------------------------------\n"); +} + + +//uses buddy system allocation +void init_memory() { + struct memory_table *memtable = (struct memory_table *)&_meminfo_loc; + struct phys_map *map = (struct phys_map*)0x200000; + uintptr_t onpage = 0x200000; + unsigned int i, x, buddy_size, buddy_bitsize, prev_buddy_bsize; + uint64_t *buddy_ptr; + + map_page((void*)0x200000, (void*)0x200000, PAGE_SIZE_2M); + void *next_page = (void *)onpage + 0x200000; + // at this point, we are declaring our header and kernel itself as free (so don't forget to fix that!) + + for(i = 0; memtable[i].length > 0; i++) { + if((memtable[i].type == MEM_AVAILABLE) && (memtable[i].ACPI & 1)) { + + map->chunk_start = (void*)memtable[i].base; + map->chunk_size = memtable[i].length; + buddy_ptr = (void*)&map->buddies; + + + for(x = 0; x < 8; x++) { + + buddy_bitsize = memtable[i].length / (0x1000 * (1 << x)); + buddy_size = ceil(buddy_bitsize / (float)8); + + if((void *)buddy_ptr + buddy_size >= next_page) { + map_page(next_page, next_page, PAGE_SIZE_2M); + next_page += 0x200000; + } + + bzero(buddy_ptr, buddy_size); //meant to be /8? + + if((buddy_bitsize * 2) != prev_buddy_bsize) { + buddy_ptr[-1] |= (1 << ((prev_buddy_bsize % 8) - 1)); + } + + buddy_ptr += buddy_size; + + prev_buddy_bsize = buddy_bitsize; + + } + map->map_size = buddy_ptr - (uint64_t*)map; + map = (struct phys_map *)map + map->map_size; + + if((void *)map + 24 >= next_page) { + map_page(next_page, next_page, PAGE_SIZE_2M); + next_page += 0x200000; + } + } + } +} + +//TODO this function was deleted due to it being wrong. +//I'll create it once I have the physical paging prerequisite set up. +void create_pagetable_stage2(uint64_t free_mem) { +} + + +/** + * BIG TODO: + * Paging turned out to be simpler then I thought. I've temporarily fixed the code, but needs to be rewritten/simplified. + * Let's get rid of those nasty GOTOs if we can. + * Also, once we get physical memory allocator up and running, impliment that in this function. +**/ + +bool map_page(void *virtual_addr, void *physical_addr, uint8_t size) { + //printf("map page called\n"); + uintptr_t va_ptr = (uintptr_t)virtual_addr; + uintptr_t pa_ptr = (uintptr_t)physical_addr; + if((va_ptr % (1 << size)) || (pa_ptr % (1 << size))) { + return 0; + } + page_table *table = (page_table *)PAGEMAP_LOCATION; + int pte_i = (va_ptr >> 12) & 0x1ff; + int pde_i = (va_ptr >> 21) & 0x1ff; + int pdpe_i = (va_ptr >> 30) & 0x1ff; + int pml4e_i = (va_ptr >> 39) & 0x1ff; + + if(table->pml4e[pml4e_i].present) { + if(table->pml4e[pml4e_i].base_ptr != (uintptr_t)&table->pdpe[pdpe_i] >> 12) goto error; + if(table->pdpe[pdpe_i].present) { + if(size == PAGE_SIZE_1G) { + if(table->pdpe[pdpe_i].base_ptr == (uintptr_t)pa_ptr >> 30 & 0x1ff) + return true; + goto error; + } + if(table->pdpe[pdpe_i].base_ptr != (uintptr_t)&table->pde[pde_i] >> 12) goto error; + + if(table->pde[pde_i].present) { + if(size == PAGE_SIZE_2M) { + if(table->pde[pde_i].base_ptr == (uintptr_t)pa_ptr >> 21 & 0x1ff) + return true; + goto error; + } + if(table->pde[pde_i].base_ptr != (uintptr_t)&table->pte[pte_i] >> 12) goto error; + if(table->pte[pte_i].present) { + if(table->pte[pte_i].base_ptr != ((pa_ptr >> 12) & 0x1ff)) goto error; + return true; + } + else goto mod_page_pte; + } + else goto mod_page_pde; + } + else goto mod_page_pdpe; + } + else { + table->pml4e[pml4e_i].base_ptr = (uintptr_t)&table->pdpe[pdpe_i] >> 12; + table->pdpe[pml4e_i].read_write = 1; + table->pml4e[pml4e_i].present = 1; +mod_page_pdpe: + table->pdpe[pdpe_i].read_write = 1; + //TODO you just found out things are a lot more simple then you thought! + if(size == PAGE_SIZE_1G) { + table->pdpe[pdpe_i].size = 1; + table->pdpe[pdpe_i].base_ptr = pa_ptr >> 12; + table->pdpe[pdpe_i].present = 1; + return true; + } + table->pdpe[pdpe_i].base_ptr = (uintptr_t)&table->pde[pde_i] >> 12; + table->pdpe[pdpe_i].present = 1; +mod_page_pde: + table->pde[pde_i].read_write = 1; + if(size == PAGE_SIZE_2M) { + table->pde[pde_i].size = 1; + table->pde[pde_i].base_ptr = pa_ptr >> 12; + table->pde[pde_i].present = 1; + return true; + } + table->pde[pde_i].base_ptr = (uintptr_t)&table->pte[pte_i] >> 12; + table->pde[pde_i].present = 1; +mod_page_pte: + table->pte[pte_i].base_ptr = pa_ptr >> 12; + table->pte[pte_i].read_write = 1; + table->pte[pte_i].present = 1; + return true; + } +error: + printf("Page allocation error!\n"); + return false; +} -- cgit v1.2.3