Small adjustment in directory structure of memory and bootloader files in kernel

This commit is contained in:
Nigel Barink 2021-11-02 21:15:00 +01:00
parent c9b789ed7b
commit bdcf9e66f8
11 changed files with 17 additions and 137 deletions

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@ -5,7 +5,7 @@ CC = ${HOME}/opt/cross/bin/i686-elf-gcc
CPP = ${HOME}/opt/cross/bin/i686-elf-g++
CFLAGS = -ffreestanding -O2 -Wall -Wextra
OFILES = $(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/io.o $(BUILD_DIR)/MMU.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/string.o
OFILES = $(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/io.o $(BUILD_DIR)/PageDirectory.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/string.o
SRC_DIR = src
BUILD_DIR = build
@ -71,8 +71,8 @@ $(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
$(BUILD_DIR)/MMU.o:
$(CPP) -c $(SRC_DIR)/kernel/MMU.cpp -o $(BUILD_DIR)/MMU.o $(CFLAGS) -fno-exceptions -fno-rtti
$(BUILD_DIR)/PageDirectory.o:
$(CPP) -c $(SRC_DIR)/kernel/memory/PageDirectory.cpp -o $(BUILD_DIR)/PageDirectory.o $(CFLAGS) -fno-exceptions -fno-rtti
$(BUILD_DIR)/idt.o:
$(CPP) -c $(SRC_DIR)/kernel/arch/i386/idt/idt.cpp -o $(BUILD_DIR)/idt.o $(CFLAGS) -fno-exceptions -fno-rtti

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@ -1,5 +1,5 @@
#pragma once
#include "multiboot.h"
#include "bootloader/multiboot.h"
#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
extern "C" {

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@ -1,16 +1,13 @@
#pragma once
extern "C" {
#include "arch/i386/tty/kterm.h"
#include "pmm.h"
}
#include "../libc/include/string.h"
#include "multiboot.h"
#include "./bootloader/multiboot.h"
#include "bootcheck.h"
#include "arch/i386/idt/idt.h"
#include "MMU.h"
#include "io.h"
#include "time.h"
#include "cpu.h"

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@ -1,9 +1,9 @@
#include "MMU.h"
#include "PageDirectory.h"
#include <stdint.h>
void MMU::enable(){
void PageDirectory::enable(){
//set each entry to not present
int i;

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@ -18,7 +18,7 @@ struct page_table_entry{};
class MMU {
class PageDirectory {
public:
void enable ();

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@ -0,0 +1 @@
#include "PageFrameAllocator.h"

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@ -0,0 +1,8 @@
#pragma once
#include <stdint.h>
extern void *kernel_begin;
extern void *kernel_end;

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@ -1 +0,0 @@
#include "pmm.h"

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@ -1,125 +0,0 @@
#pragma once
#include <stdint.h>
// Lets assume we have 2 gigabytes of memory
// NOTE: We should really detect how much memory we have
#define KiloByte 1024 // bytes
#define MegaByte 1048576 // bytes
#define GigaByte 1073741824 // bytes
#define MemorySize 2147483648 // bytes
const uint32_t bitmapSize = MemorySize / 8;
extern void *kernel_begin;
extern void *kernel_end;
struct __attribute__((packed)) PMSegment {
void* address;
uint32_t size;
PMSegment* Next;
};
static PMSegment pmStart;
static uint32_t AvailablePhysicalMemory;
static uint32_t AllocatedMemorySize;
void initPhysicalMemoryManager(){
AvailablePhysicalMemory = MemorySize;
AllocatedMemorySize = 0;
// Map the kernel
PMSegment KernelSegment = PMSegment();
printf("end of kernel: 0x%x\n", &kernel_end);
printf("start of kernel: 0x%x\n", &kernel_begin);
printf("pointer to kernel: 0x%x\n", &KernelSegment);
pmStart = KernelSegment;
KernelSegment.address = kernel_begin;
KernelSegment.size = &kernel_end - &kernel_begin;
AllocatedMemorySize += KernelSegment.size;
KernelSegment.Next = 0;
// make sure We allocate space for ourselves
/*PMSegment start = PMSegment();
start.address = KernelSegment.address + KernelSegment.size ;
start.size = (MemorySize / sizeof(PMSegment) ) + sizeof (uint32_t) * 2;
*/
//KernelSegment.Next = &start;
//AllocatedMemorySize += start.size;
}
void printMemorySegments()
{
printf("Memory Segments:\n");
printf( "Start Segment: [addr: 0x%x, size: 0x%x, Next: 0x%x]\n" ,pmStart.address, pmStart.size, pmStart.Next);
printf("----------------------------\n");
}
void pmem_free (void* address){
PMSegment* before = 0;
PMSegment* current = &pmStart;
printf("Address of pmStart : 0x%x\n", pmStart);
printf("Looking for segment with address: 0x%x \n", address );
printf("Address of pmStart(a.k.a current) : 0x%x \n", current);
while( current )
{
//printf("address of current segment 0x%x\n", current->address );
if ( current->address == address ) {
// this is the address we want to free
printf("Segment found!! Segment address: 0x%x \n", current->address);
if ( current->Next && before ){
before->Next = current->Next;
}else{
before->Next = 0;
}
// TODO: Clean memory [ Something like memset to zeroes]
printf("Removing segment of size: 0x%x\n", current->size);
AllocatedMemorySize -= current->size;
break;
}
before = current;
current = current->Next;
}
}
void* pmem_alloc ( uint32_t size ){
// Get the last segment
PMSegment* lastSegment = &pmStart;
while (lastSegment ) {
if( lastSegment->Next == 0){
break;
}
lastSegment = lastSegment->Next;
}
printf("LastSegment is for address: 0x%x\n", lastSegment->address);
// So now we have the last segment available
PMSegment newSegment = PMSegment();
newSegment.address = (PMSegment*)((uint32_t)lastSegment->address + lastSegment->size +1);
printf("NewSegment for Address: 0x%x\n", newSegment.address);
newSegment.size = size;
lastSegment->Next = &newSegment;
if ( AllocatedMemorySize + newSegment.size > AvailablePhysicalMemory){
// No segment available of this size
/// ERROR!!
return 0;
}
AllocatedMemorySize += newSegment.size;
return newSegment.address;
}