Nigel
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BarinkOS
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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)
dev
Nigel Barink 2022-08-22 21:16:34 +02:00
parent 0f0fc9f252
commit 5051b8903c
16 changed files with 206 additions and 253 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Makefile
View File

@ -5,7 +5,7 @@ CC = ${HOME}/opt/cross/bin/i686-elf-gcc
CPP = ${HOME}/opt/cross/bin/i686-elf-g++
CFLAGS = -ffreestanding -Og -ggdb -Wall -Wextra
OFILES =$(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/memory.o $(BUILD_DIR)/paging.o $(BUILD_DIR)/pit.o $(BUILD_DIR)/time.o $(BUILD_DIR)/keyboard.o $(BUILD_DIR)/io.o $(BUILD_DIR)/gdtc.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/sv-terminal.o $(BUILD_DIR)/string.o $(BUILD_DIR)/launcher.o
OFILES =$(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/memory.o $(BUILD_DIR)/paging.o $(BUILD_DIR)/pit.o $(BUILD_DIR)/time.o $(BUILD_DIR)/keyboard.o $(BUILD_DIR)/io.o $(BUILD_DIR)/gdtc.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/sv-terminal.o $(BUILD_DIR)/string.o $(BUILD_DIR)/prekernel.o
SRC_DIR = source
BUILD_DIR = build
@ -30,7 +30,7 @@ clean_iso:
iso: clean_iso clean build
mkdir -p root/boot/grub
cp build/myos.bin root/boot/myos.bin
cp src/grub.cfg root/boot/grub/grub.cfg
cp source/grub.cfg root/boot/grub/grub.cfg
grub-mkrescue -o build/barinkOS.iso root
run: all
@ -58,13 +58,13 @@ $(BUILD_DIR)/kterm.o:
$(CPP) -c $(SRC_DIR)/kernel/Terminal/kterm.cpp -o $(BUILD_DIR)/kterm.o $(CFLAGS) -fno-exceptions -fno-rtti
$(BUILD_DIR)/boot.o:
$(AS) $(SRC_DIR)/kernel/KernelLauncher/boot.s -o $(BUILD_DIR)/boot.o
$(AS) $(SRC_DIR)/kernel/Boot/boot.s -o $(BUILD_DIR)/boot.o
$(BUILD_DIR)/crti.o:
$(AS) $(SRC_DIR)/kernel/KernelLauncher/crti.s -o $(BUILD_DIR)/crti.o
$(AS) $(SRC_DIR)/kernel/crti.s -o $(BUILD_DIR)/crti.o
$(BUILD_DIR)/crtn.o:
$(AS) $(SRC_DIR)/kernel/KernelLauncher/crtn.s -o $(BUILD_DIR)/crtn.o
$(AS) $(SRC_DIR)/kernel/crtn.s -o $(BUILD_DIR)/crtn.o
$(BUILD_DIR)/io.o:
$(CPP) -c $(SRC_DIR)/kernel/io.cpp -o $(BUILD_DIR)/io.o $(CFLAGS) -fno-exceptions -fno-rtti
@ -104,5 +104,5 @@ $(BUILD_DIR)/memory.o:
$(BUILD_DIR)/paging.o:
$(CPP) -c $(SRC_DIR)/kernel/Memory/VirtualMemoryManager.cpp -o $(BUILD_DIR)/paging.o $(CFLAGS) -fno-exceptions -fno-rtti
$(BUILD_DIR)/launcher.o:
$(CPP) -c $(SRC_DIR)/kernel/KernelLauncher/launcher.cpp -o $(BUILD_DIR)/launcher.o $(CFLAGS) -fno-exceptions -fno-rtti
$(BUILD_DIR)/prekernel.o:
$(CPP) -c $(SRC_DIR)/kernel/PreKernel/prekernel.cpp -o $(BUILD_DIR)/prekernel.o $(CFLAGS) -fno-exceptions -fno-rtti

6
source/grub.cfg
View File

@ -1,3 +1,9 @@
menuentry "BarinkOS" {
multiboot /boot/myos.bin
}
menuentry "BarinkOS Tests" {
multiboot /boot/myos.bin
}

24
source/kernel/KernelLauncher/boot.s → source/kernel/Boot/boot.s
View File

@ -43,6 +43,14 @@ multiboot_page_table:
.global _start
.type _start, @function
_start:
/* push the pointer to the Multiboot information structure*/
pushl %ebx
/* push the magic value */
pushl %eax
call testLauncher
# Get physical address of the boot_page_table
movl $(boot_page_table - 0xC0000000), %edi
# Map address 0
@ -112,11 +120,7 @@ isPaging:
pushl $0
popf
/* push the pointer to the Multiboot information structure*/
pushl %ebx
/* push the magic value */
pushl %eax
call early_main
@ -129,11 +133,11 @@ isPaging:
jmp 1b
.include "./src/kernel/Memory/GDT/gdt.s"
.include "./src/kernel/irs_table.s"
.include "./src/kernel/irq_table.s"
.include "./src/kernel/Interrupts/idt/idt.s"
.include "./src/kernel/Memory/paging.s"
.include "./src/kernel/cpu.s"
.include "./source/kernel/Memory/GDT/gdt.s"
.include "./source/kernel/irs_table.s"
.include "./source/kernel/irq_table.s"
.include "./source/kernel/Interrupts/idt/idt.s"
.include "./source/kernel/Memory/paging.s"
.include "./source/kernel/cpu.s"

91
source/kernel/KernelLauncher/bootcheck.h
View File

@ -1,91 +0,0 @@
#pragma once
#include "../multiboot.h"
#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
#define __VERBOSE__
#include "../Terminal/kterm.h"
void CheckMBT ( multiboot_info_t* mbt ){
/* Set MBI to the addresss of the multiboot information structure*/
multiboot_info_t * mbi = (multiboot_info_t *) mbt;
#ifdef __VERBOSE__
/* Print out the flags */
printf("flags = 0x%x\n", (unsigned) mbi->flags);
#endif
/* Are mem_* valid? */
if ( CHECK_FLAG(mbi->flags,0)){
// Do nothing
}
/* is boot device valid ? */
if (CHECK_FLAG (mbi->flags, 1))
{
#ifdef __VERBOSE__
printf("boot_device = 0x0%x\n", (unsigned) mbi->boot_device);
#endif
}
/* is the command line passed? */
if (CHECK_FLAG ( mbi->flags,2))
{
#ifdef __VERBOSE__
printf("cmdline = %s\n", (char *) (mbi->cmdline + 0xC0000000));
#endif
}
/* Are mods_* valid? */
if(CHECK_FLAG ( mbi->flags, 3)){
multiboot_module_t *mod;
uint32_t i;
#ifdef __VERBOSE__
printf("mods count = %d, mods_addr = 0x%x\n", (int) mbi->mods_count, (int) mbi->mods_addr);
for(i = 0, mod = (multiboot_module_t *) mbi->mods_addr; i < mbi->mods_count; i++ , mod++){
printf(" mod start = 0x%x, mod_end = 0x%x, cmdline = %s\n", (unsigned) mod->mod_start, (unsigned) mod->mod_end, (char*) mod->cmdline);
}
#endif
}
/* Bits 4 and 5 are mutually exclusive! */
if (CHECK_FLAG (mbi->flags, 4) && CHECK_FLAG(mbi->flags, 5))
{
#ifdef __VERBOSE__
printf("Both bits 4 and 5 are set.\n");
#endif
return;
}
/* Is the symbol table of a.out valid? */
if (CHECK_FLAG(mbi->flags, 4)){
multiboot_aout_symbol_table_t *multiboot_aout_sym = &(mbi->u.aout_sym);
#ifdef __VERBOSE__
printf( "multiboot_aout_symbol_table: tabsize = 0x%0x, strsize = 0x%x, addr = 0x%x\n",
(unsigned) multiboot_aout_sym->tabsize,
(unsigned) multiboot_aout_sym->strsize,
(unsigned) multiboot_aout_sym->addr);
#endif
}
/* Is the section header table of ELF valid? */
if (CHECK_FLAG(mbi->flags, 5)){
multiboot_elf_section_header_table_t *multiboot_elf_sec = &(mbi->u.elf_sec);
#ifdef __VERBOSE__
printf("multiboot_elf_sec: num = %u, size = 0x%x, addr = 0x%x, shnd = 0x%x\n",
(unsigned) multiboot_elf_sec->num, (unsigned) multiboot_elf_sec->size,
(unsigned) multiboot_elf_sec->addr, (unsigned) multiboot_elf_sec->shndx);
#endif
}
/* Draw diagonal blue line */
if (CHECK_FLAG (mbt->flags, 12)){
#ifdef __VERBOSE__
printf("Can draw!\n");
#endif
}
}

28
source/kernel/KernelLauncher/launcher.cpp
View File

@ -1,28 +0,0 @@
#include <stdint.h>
#include <stddef.h>
void put_char(char ch, size_t x, size_t y ){
*((uint16_t*)0xb8000+(y * 80 + x)) = ch | ((7 | 0 << 4) << 8);
}
void write_ln(char* s, size_t length, size_t x , size_t y)
{
// Because read only data is linked at a virtual address we'll need to convert
// the string adddres from virtual to phys.
s = s - 0xC0000000;
size_t column , row;
column = x;
row = y;
for(int i = 0; i < length ; i ++)
{
put_char(s[i] , column,row );
column ++;
}
}
extern "C" void testLauncher () {
write_ln("hello", 5 ,0,0);
}

7
source/kernel/Memory/MBIMMap/MBI_MMap.cpp
View File

@ -1,6 +1,6 @@
#include "MBI_MMap.h"
/*
void mapMultibootMemoryMap( MemoryInfo* memInfo , multiboot_info_t *mbt) {
printf("mmap_addr = 0x%x, mmap_length = 0x%x\n", (unsigned) mbt->mmap_addr , (unsigned) mbt->mmap_length );
@ -23,13 +23,13 @@ void mapMultibootMemoryMap( MemoryInfo* memInfo , multiboot_info_t *mbt) {
}
*/
/**
* @brief Debug Verbose functions
*
* @param mmap
*/
/*
void print_Multiboot_memory_Map(multiboot_memory_map_t* mmap) {
printf(
"size = 0x%x, base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
@ -41,3 +41,4 @@ void print_Multiboot_memory_Map(multiboot_memory_map_t* mmap) {
(unsigned) mmap->type
);
}
*/

8
source/kernel/Memory/MBIMMap/MBI_MMap.h
View File

@ -1,16 +1,18 @@
#pragma once
#include <stddef.h>
#include "../../multiboot.h"
//#include "../../multiboot.h"
#include "../memoryinfo.h"
void initialise_available_regions(uint32_t memoryMapAddr, uint32_t memoryMapLastAddr, uint32_t* memoryBitMap, int* used_blocks);
/*
void mapMultibootMemoryMap( MemoryInfo* memInfo , multiboot_info_t *mbt);
*/
/**
* @brief Debug Verbose Functions
*
* @param mmap
*/
/*
void print_Multiboot_memory_Map(multiboot_memory_map_t* mmap);
*/

28
source/kernel/PreKernel/bootstructure.h Normal file
View File

@ -0,0 +1,28 @@
#pragma once
#include <stddef.h>
#include <stdint.h>
extern "C" const uint32_t kernel_begin;
extern "C" const uint32_t kernel_end;
struct BootInfoBlock {
bool MapIsInvalid;
uint32_t bootDeviceID ;
uint32_t GrubModuleCount;
bool ValidSymbolTable;
uint32_t SymbolTableAddr;
uint32_t SymbolTabSize;
uint32_t SymbolStrSize;
bool ValidELFHeader;
bool EnabledVBE;
bool PhysicalMemoryMapAvailable;
};
// Put the BootInfoBlock 1MB above the kernel.
const uint32_t BootInfoBlock_pptr = kernel_end - 0xC0000000 + 0x1000;

0
source/kernel/multiboot.h → source/kernel/PreKernel/multiboot.h
View File

93
source/kernel/PreKernel/prekernel.cpp Normal file
View File

@ -0,0 +1,93 @@
#include <stdint.h>
#include <stddef.h>
#include "multiboot.h"
#include "bootstructure.h"
#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
extern "C" void testLauncher ( unsigned long magic, multiboot_info_t* mbi) {
// Create the bootInfoBlock at its location
BootInfoBlock* BIB = (BootInfoBlock*) BootInfoBlock_pptr;
/*
* Check Multiboot magic number
*/
if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
{
BIB->MapIsInvalid = true;
return;
} else{
BIB->MapIsInvalid = false;
}
/* is boot device valid ? */
if (CHECK_FLAG (mbi->flags, 1))
{
BIB->bootDeviceID = mbi->boot_device;
}
/* Are mods_* valid? */
if(CHECK_FLAG ( mbi->flags, 3)){
multiboot_module_t *mod;
uint32_t i;
BIB->GrubModuleCount = mbi->mods_count;
for(i = 0, mod = (multiboot_module_t *) mbi->mods_addr; i < mbi->mods_count; i++ , mod++){
}
}
/* Is the symbol table of a.out valid? */
if (CHECK_FLAG(mbi->flags, 4))
{
BIB->ValidSymbolTable = true;
multiboot_aout_symbol_table_t *multiboot_aout_sym = &(mbi->u.aout_sym);
} else{
BIB->ValidSymbolTable = false;
}
/* Is the section header table of ELF valid? */
if (CHECK_FLAG(mbi->flags, 5))
{
BIB->ValidELFHeader = true;
multiboot_elf_section_header_table_t *multiboot_elf_sec = &(mbi->u.elf_sec);
}else{
BIB->ValidELFHeader = false;
}
/*
If we got a memory map from our bootloader we
should be parsing it to find out the memory regions available.
*/
if (CHECK_FLAG(mbi->flags, 6))
{
BIB->PhysicalMemoryMapAvailable = true;
multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) (mbi->mmap_addr) ;
for (; (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length; mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
if ( mmap->type == MULTIBOOT_MEMORY_AVAILABLE){
} else{
}
}
} else{
BIB->PhysicalMemoryMapAvailable = false;
}
/* Draw diagonal blue line */
if (CHECK_FLAG (mbi->flags, 12)){
BIB->EnabledVBE = true;
} else{
BIB->EnabledVBE;
}
}

4
source/kernel/Terminal/kterm.cpp
View File

@ -22,6 +22,7 @@ void kterm_init () {
kterm_column = 0;
kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
kterm_buffer = (uint16_t*) 0xC03FF000;
for (size_t y = 0; y < VGA_HEIGHT; y++ ){
for( size_t x = 0; x < VGA_WIDTH; x++){
const size_t index = y * VGA_WIDTH + x;
@ -31,7 +32,6 @@ void kterm_init () {
}
}
void kterm_resetcolor(){
kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
}
@ -42,9 +42,7 @@ void kterm_setcolor(uint8_t color){
void kterm_putat (char c, uint8_t color, size_t x, size_t y ) {
const size_t index = y * VGA_WIDTH + x;
kterm_buffer[index] = vga_entry(c, color);
}
void enable_cursor (uint8_t start_cursor , uint8_t end_cursor ){

0
source/kernel/KernelLauncher/crti.s → source/kernel/crti.s
View File

0
source/kernel/KernelLauncher/crtn.s → source/kernel/crtn.s
View File

145
source/kernel/kernel.cpp
View File

@ -1,15 +1,13 @@
#include "kernel.h"
extern "C" void early_main(unsigned long magic, unsigned long addr){
// Convert MBI address to higher quarter kernel space
addr += KERNEL_BASE_ADDR;
/**
extern "C" void early_main()
{
/*
* Initialize terminal interface
* NOTE: This should be done later on , the magic value should be checked first.
*/
initGDT();
kterm_init();
init_serial();
print_serial("Hello Higher half kernel!\n");
@ -17,110 +15,38 @@ extern "C" void early_main(unsigned long magic, unsigned long addr){
// Enable interrupts
asm volatile("STI");
printf("DEBUG:\n Magic: 0x%x\n MBT_addr: 0x%x\n", magic, addr);
/**
* Check Multiboot magic number
* NOTE: Printf call should not be a thing this early on ...
*/
if (magic != MULTIBOOT_BOOTLOADER_MAGIC){
printf("Invalid magic number: 0x%x\n", magic);
return;
}
/**
/*
* Show a little banner for cuteness
*/
printf("|=== BarinkOS ===|\n");
/**
* Use the address given as an argument as the pointer
* to a Multiboot information structure.
*/
multiboot_info_t* mbt = (multiboot_info_t*) (addr );
/**
* Construct our own bootInfo structure
*/
BootInfo bootinfo = {};
/*
If we got a memory map from our bootloader we
should be parsing it to find out the memory regions available.
*/
if (CHECK_FLAG(mbt->flags, 6))
{
/*
Setup Physical memory managment
*/
MemoryInfo meminfo = {};
bootinfo.memory = &meminfo;
///mapMultibootMemoryMap(bootinfo.memory , mbt);
printf("Memory size: 0x%x bytes\n", bootinfo.memory->TotalMemory );
BootInfoBlock* BootInfo = (BootInfoBlock*) ( BootInfoBlock_pptr + 0xC0000000 );
/*
PhysicalMemory memAlloc = PhysicalMemory{};
memAlloc.setup(bootinfo.memory );
*/
printf("Bootloader information:\n");
if( BootInfo->ValidELFHeader )
{
printf("- Valid ELF Header is available!\n");
}
// TODO: FIX physical allocator
/*
Mark already in use sections
*/
// Mark kernel memory as used
printf("Kernel Begin Pointer: 0x%x, Kernel end pointer: 0x%x\n", &kernel_begin , &kernel_end );
multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) (mbt->mmap_addr + KERNEL_BASE_ADDR) ;
if(BootInfo->EnabledVBE)
{
printf("- VBE graphics mode is available!\n");
}
for (; (unsigned long) mmap < mbt->mmap_addr + mbt->mmap_length; mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
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 ( mmap->type == MULTIBOOT_MEMORY_AVAILABLE){
} else{
printf("allocate region: 0x%x, size : 0x%x bytes\n", (unsigned) mmap->addr,(unsigned) mmap->len );
// memAlloc.allocate_region((unsigned)mmap->addr , (unsigned)mmap->len);
}
}
printf("allocate region: 0x%x, size : 0x%x bytes\n", &kernel_begin, &kernel_end - &kernel_begin );
//memAlloc.allocate_region(kernel_end, kernel_end - kernel_begin);
// 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();
*/
//memAlloc.free_block((void*) memory);
//InitializePaging();
//IdentityMap();
//Enable();
} else{
printf("memory flag not set!");
if(BootInfo->PhysicalMemoryMapAvailable)
{
printf("- Physical Memory Map available!\n");
}
CheckMBT( (multiboot_info_t *) addr);
asm volatile("mov %cr0, %eax ");
asm volatile("or $1, %eax");
asm volatile("mov %eax, %cr0");
kernel_main(&bootinfo);
kernel_main();
}
@ -151,9 +77,28 @@ void map_multiboot_info_structure(unsigned long addr){
asm("movl %cr3, %ecx;" "movl %ecx, %cr3" );
}
extern "C" void kernel_main (BootInfo* bootinfo) {
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);
}

9
source/kernel/kernel.h
View File

@ -3,19 +3,16 @@ extern "C"
{
#include "Lib/string.h"
}
#include "definitions.h"
#include "Drivers/VGA/VBE.h"
#include "Terminal/kterm.h"
#include "multiboot.h"
#include "bootinfo.h"
#include "Memory/PhysicalMemoryManager.h"
#include "Memory/memoryinfo.h"
#include "Memory/VirtualMemoryManager.h"
#include "KernelLauncher/bootcheck.h"
#include "Memory/GDT/gdtc.h"
#include "Interrupts/idt/idt.h"
@ -27,17 +24,15 @@ extern "C"
#include "time.h"
#include "SuperVisorTerminal/superVisorTerminal.h"
#include "PreKernel/bootstructure.h"
#define CHECK_FLAG(flag, bit) ( flag & (1 << bit ))
#define PANIC(message) {return;}
void map_multiboot_info_structure(unsigned long addr);
extern "C" void kernel_main (BootInfo* bootinfo);
extern "C" void kernel_main ();
extern "C" const void* kernel_begin;
extern "C" const void* kernel_end;
extern "C" uint32_t boot_page_directory;
extern "C" uint32_t multiboot_page_table;

2
source/kernel/linker.ld
View File

@ -16,7 +16,7 @@ SECTIONS
.multiboot.text : {
*(multiboot.text)
*launcher.o(.text)
*prekernel.o(.text)
}
. += 0xC0000000; /* Addresses in the following code need to be above the 3Gb mark */