Nigel
13e9beea79
Folders now are alll lower case Started working on the implementation of the Virtual memory manager. Implemented allocate and free page funtionality for as far as I can atm. Implemented the
121 lines
3.5 KiB
C++
121 lines
3.5 KiB
C++
#include <stdint.h>
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#include <stddef.h>
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#include "multiboot.h"
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#include "bootstructure.h"
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#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
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extern "C" void prekernelSetup ( unsigned long magic, multiboot_info_t* mbi) {
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// Create the bootInfoBlock at its location
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BootInfoBlock* BIB = (BootInfoBlock*) BootInfoBlock_pptr;
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/*
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* Check Multiboot magic number
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*/
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if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
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{
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BIB->MapIsInvalid = true;
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// crash
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return;
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} else{
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BIB->MapIsInvalid = false;
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}
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/* is boot device valid ? */
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if (CHECK_FLAG (mbi->flags, 1))
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{
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BIB->bootDeviceID = mbi->boot_device;
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} else{
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BIB->bootDeviceID = 0x11111111;
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}
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/* Are mods_* valid? */
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if(CHECK_FLAG ( mbi->flags, 3)){
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multiboot_module_t *mod;
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uint32_t i;
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BIB->GrubModuleCount = mbi->mods_count;
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for(i = 0, mod = (multiboot_module_t *) mbi->mods_addr; i < mbi->mods_count; i++ , mod++){
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}
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}
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/* Is the symbol table of a.out valid? */
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if (CHECK_FLAG(mbi->flags, 4))
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{
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BIB->ValidSymbolTable = true;
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multiboot_aout_symbol_table_t *multiboot_aout_sym = &(mbi->u.aout_sym);
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} else{
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BIB->ValidSymbolTable = false;
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}
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/* Is the section header table of ELF valid? */
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if (CHECK_FLAG(mbi->flags, 5))
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{
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BIB->ValidELFHeader = true;
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multiboot_elf_section_header_table_t *multiboot_elf_sec = &(mbi->u.elf_sec);
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}else{
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BIB->ValidELFHeader = false;
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}
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/*
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If we got a memory map from our bootloader we
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should be parsing it to find out the memory regions available.
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*/
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if (CHECK_FLAG(mbi->flags, 6))
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{
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BIB->PhysicalMemoryMapAvailable = true;
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BIB->MemoryMap = (MemoryInfoBlock*) MemoryMapHeap_pptr;
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multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) (mbi->mmap_addr) ;
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auto MemoryMapEnd = mbi->mmap_addr + mbi->mmap_length;
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auto CurrentInfoBlock = BIB->MemoryMap;
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uint32_t RAM_size = 0;
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while((unsigned long) mmap < MemoryMapEnd){
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BIB->map_size += sizeof(MemoryInfoBlock);
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CurrentInfoBlock->Base_addr = mmap->addr;
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CurrentInfoBlock->Memory_Size = mmap->len;
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if(mmap->type == MULTIBOOT_MEMORY_AVAILABLE)
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CurrentInfoBlock->type |= 0x1;
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RAM_size += mmap->len;
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if(mmap->type == MULTIBOOT_MEMORY_ACPI_RECLAIMABLE)
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CurrentInfoBlock->type |= 0x2;
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if(mmap->type == MULTIBOOT_MEMORY_RESERVED)
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CurrentInfoBlock->type |= 0x4;
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if(mmap->type == MULTIBOOT_MEMORY_NVS)
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CurrentInfoBlock->type |= 0x8;
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if(mmap->type == MULTIBOOT_MEMORY_BADRAM)
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CurrentInfoBlock->type |= 0x10;
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// continue to the next block
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mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size));
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CurrentInfoBlock->next = (MemoryInfoBlock*) ((uint32_t)CurrentInfoBlock) + sizeof(MemoryInfoBlock);
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CurrentInfoBlock = CurrentInfoBlock->next;
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}
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CurrentInfoBlock->next = (MemoryInfoBlock*) 0x0;
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BIB->MemorySize = RAM_size;
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} else
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{
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BIB->PhysicalMemoryMapAvailable = false;
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}
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/* Draw diagonal blue line */
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if (CHECK_FLAG (mbi->flags, 12)){
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BIB->EnabledVBE = true;
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} else{
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BIB->EnabledVBE;
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}
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}
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