BarinkOS/source/kernel/kernel.cpp
Nigel 5051b8903c Divided the kernel into seperate distinct phases
The first stage after GRUB will be Pre-Kernel. This stage will organize the
information we receive from the bootloader. (in our case that will be grub)

The second stage is for now called early_main. The program will at this
point already be running in virtual higher-half / higher-quarter address space.
The goal of the second stage is to set up the kernel in such a way that we are
ready to jump in to usermode.

The third stage is for now called kernel_main. This stage will jump us into
usermode and load the startup programs.

- Added a GRUB entry for tests
- Started writing the pre-kernel stage
- Removed knowledge of multiboot from early_main
- Edited the linkerscript to link variables in pre-kernel to
	lower address space. ( from 1MB and up)
2022-08-22 21:16:34 +02:00

104 lines
2.8 KiB
C++

#include "kernel.h"
extern "C" void early_main()
{
/*
* Initialize terminal interface
*/
initGDT();
kterm_init();
init_serial();
print_serial("Hello Higher half kernel!\n");
init_idt();
// Enable interrupts
asm volatile("STI");
/*
* Show a little banner for cuteness
*/
printf("|=== BarinkOS ===|\n");
BootInfoBlock* BootInfo = (BootInfoBlock*) ( BootInfoBlock_pptr + 0xC0000000 );
printf("Bootloader information:\n");
if( BootInfo->ValidELFHeader )
{
printf("- Valid ELF Header is available!\n");
}
if(BootInfo->EnabledVBE)
{
printf("- VBE graphics mode is available!\n");
}
if(BootInfo->ValidSymbolTable)
{
printf("- Valid Symbol Table available at 0x%x.\n Tab Size: %d, str Size: %d\n", BootInfo->SymbolTableAddr, BootInfo->SymbolTabSize, BootInfo->SymbolStrSize);
}
if(BootInfo->PhysicalMemoryMapAvailable)
{
printf("- Physical Memory Map available!\n");
}
asm volatile("mov %cr0, %eax ");
asm volatile("or $1, %eax");
asm volatile("mov %eax, %cr0");
kernel_main();
}
void map_multiboot_info_structure(unsigned long addr){
// map the multiboot structure into virtual memory
// so we can gather the necessary data from it.
uint32_t pageDirectoryIndex = (addr ) >> 22;
printf("pageDirectoryIndex: %d\n", pageDirectoryIndex);
uint32_t pageTableIndex = (addr >> 12) & 0x1FFF;
printf("PagTableIndex: %d\n", pageTableIndex);
printf("boot_page_directory addr: 0x%x\n", &boot_page_directory);
printf("boot_page_table addr: 0x%x\n", &multiboot_page_table);
uint32_t* current_page_directory = &boot_page_directory;
uint32_t* needed_page_table = &multiboot_page_table - KERNEL_BASE_ADDR;
// set the page tabel reference;
current_page_directory[pageDirectoryIndex] = (uint32_t)&multiboot_page_table - KERNEL_BASE_ADDR + 0x003;
// set the page reference;
needed_page_table[ pageTableIndex ] = addr | 0x003;
// Reload CR3 to force a flush
asm("movl %cr3, %ecx;" "movl %ecx, %cr3" );
}
void PhysicalMemoryAllocatorTest(){
#ifdef UNIT_TESTS
// test alloc_block
uint8_t* memory = (uint8_t*) memAlloc.allocate_block();
printf("Got a new pointer: 0x%x\n", memory);
uint8_t* memory2 = (uint8_t*) memAlloc.allocate_block();
printf("Got a new pointer: 0x%x\n", memory2);
memAlloc.free_block((void*) memory);
uint8_t* newBlockPlse = (uint8_t*) memAlloc.allocate_block();
#endif
}
extern "C" void kernel_main () {
pit_initialise();
// Create a dummy BootInfo object
// TODO: This should be done properly or the dependency should
// be removed from the SuperVisorTerminal.
BootInfo* bootinfo = {};
startSuperVisorTerminal(bootinfo);
}