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bully this crap code into working with GCC (and add GCC toolchain har har har)

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This commit is contained in:
Tyler McGurrin 2024-12-16 23:47:38 -05:00
parent ebaffb85ad
commit 60a01a977a
29 changed files with 611 additions and 1143 deletions
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5
.gitignore vendored
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@ -1,2 +1,5 @@
.vscode/
build/
build/
toolchain/
bx_enh_dbg.ini
src/bootloader/stage2_old

30
Makefile
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@ -1,16 +1,12 @@
ASM=nasm
CC=gcc
CC16=/opt/watcom/binl/wcc
LD16=/opt/watcom/binl/wlink
SRC_DIR=src
TOOLS_DIR=tools
BUILD_DIR=build
include build_scripts/config.mk
.PHONY: all floppy_image kernel bootloader clean always tools_fat
all: floppy_image tools_fat
include build_scripts/toolchain.mk
#
# Floppy image
#
@ -34,12 +30,12 @@ bootloader: stage1 stage2
stage1: $(BUILD_DIR)/stage1.bin
$(BUILD_DIR)/stage1.bin: always
$(MAKE) -C $(SRC_DIR)/bootloader/stage1 BUILD_DIR=$(abspath $(BUILD_DIR))
$(MAKE) -C src/bootloader/stage1 BUILD_DIR=$(abspath $(BUILD_DIR))
stage2: $(BUILD_DIR)/stage2.bin
$(BUILD_DIR)/stage2.bin: always
$(MAKE) -C $(SRC_DIR)/bootloader/stage2 BUILD_DIR=$(abspath $(BUILD_DIR))
$(MAKE) -C src/bootloader/stage2 BUILD_DIR=$(abspath $(BUILD_DIR))
#
@ -48,15 +44,15 @@ $(BUILD_DIR)/stage2.bin: always
kernel: $(BUILD_DIR)/kernel.bin
$(BUILD_DIR)/kernel.bin: always
$(MAKE) -C $(SRC_DIR)/kernel BUILD_DIR=$(abspath $(BUILD_DIR))
$(MAKE) -C src/kernel BUILD_DIR=$(abspath $(BUILD_DIR))
#
# Tools
#
tools_fat: $(BUILD_DIR)/tools/fat
$(BUILD_DIR)/tools/fat: always $(TOOLS_DIR)/fat/fat.c
$(BUILD_DIR)/tools/fat: always tools/fat/fat.c
mkdir -p $(BUILD_DIR)/tools
$(CC) -g -o $(BUILD_DIR)/tools/fat $(TOOLS_DIR)/fat/fat.c
$(CC) -g -o $(BUILD_DIR)/tools/fat tools/fat/fat.c
#
# Always
@ -68,8 +64,8 @@ always:
# Clean
#
clean:
$(MAKE) -C $(SRC_DIR)/bootloader/stage1 BUILD_DIR=$(abspath $(BUILD_DIR)) clean
$(MAKE) -C $(SRC_DIR)/bootloader/stage2 BUILD_DIR=$(abspath $(BUILD_DIR)) clean
$(MAKE) -C $(SRC_DIR)/kernel BUILD_DIR=$(abspath $(BUILD_DIR)) clean
$(MAKE) -C src/bootloader/stage1 BUILD_DIR=$(abspath $(BUILD_DIR)) clean
$(MAKE) -C src/bootloader/stage2 BUILD_DIR=$(abspath $(BUILD_DIR)) clean
$(MAKE) -C src/kernel BUILD_DIR=$(abspath $(BUILD_DIR)) clean
rm -rf $(BUILD_DIR)/*
rm -rf $(SRC_DIR)/bootloader/stage2/*.err
rm -rf src/bootloader/stage2/*.err

25
build_scripts/config.mk Normal file
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@ -0,0 +1,25 @@
export CFLAGS = -std=c99 -g
export ASM = nasm
export ASMFLAGS =
export CC = gcc
export CXX = g++
export LD = gcc
export LINKFLAGS =
export LIBS =
export TARGET = i686-elf
export TARGET_ASM = nasm
export TARGET_ASMFLAGS =
export TARGET_CFLAGS = -std=c99 -g
export TARGET_CC = $(TARGET)-gcc
export TARGET_CXX = $(TARGET)-g++
export TARGET_LD = $(TARGET)-gcc
export TARGET_LINKFLAGS =
export TARGET_LIBS =
export BUILD_DIR = $(abspath build)
BINUTILS_VERSION = 2.43.1
BINUTILS_URL = https://ftp.gnu.org/gnu/binutils/binutils-$(BINUTILS_VERSION).tar.gz
GCC_VERSION = 14.2.0
GCC_URL = https://ftp.gnu.org/gnu/gcc/gcc-$(GCC_VERSION)/gcc-$(GCC_VERSION).tar.gz

57
build_scripts/toolchain.mk Normal file
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@ -0,0 +1,57 @@
TOOLCHAIN_PREFIX = $(abspath toolchain/$(TARGET))
export PATH := $(TOOLCHAIN_PREFIX)/bin:$(PATH)
toolchain: toolchain_binutils toolchain_gcc
BINUTILS_SRC = toolchain/binutils-$(BINUTILS_VERSION)
BINUTILS_BUILD = toolchain/binutils-build-$(BINUTILS_VERSION)
toolchain_binutils: $(BINUTILS_SRC).tar.gz
cd toolchain && tar -xf binutils-$(BINUTILS_VERSION).tar.gz
mkdir -p $(BINUTILS_BUILD)
cd $(BINUTILS_BUILD) && ../binutils-$(BINUTILS_VERSION)/configure \
--prefix="$(TOOLCHAIN_PREFIX)" \
--target=$(TARGET) \
--with-sysroot \
--disable-nls \
--disable-werror
$(MAKE) -j10 -C $(BINUTILS_BUILD)
$(MAKE) -C $(BINUTILS_BUILD) install
$(BINUTILS_SRC).tar.gz:
mkdir -p toolchain
cd toolchain && wget $(BINUTILS_URL)
GCC_SRC = toolchain/gcc-$(GCC_VERSION)
GCC_BUILD = toolchain/gcc-build-$(GCC_VERSION)
toolchain_gcc: toolchain_binutils $(GCC_SRC).tar.gz
cd toolchain && tar -xf gcc-$(GCC_VERSION).tar.gz
mkdir -p $(GCC_BUILD)
cd $(GCC_BUILD) && ../gcc-$(GCC_VERSION)/configure \
--prefix="$(TOOLCHAIN_PREFIX)" \
--target=$(TARGET) \
--disable-nls \
--enable-languages=c,c++ \
--without-headers
$(MAKE) -j10 -C $(GCC_BUILD) all-gcc all-target-libgcc
$(MAKE) -C $(GCC_BUILD) install-gcc install-target-libgcc
$(GCC_SRC).tar.gz:
mkdir -p toolchain
cd toolchain && wget $(GCC_URL)
# CLEAN
clean-toolchain:
rm -rf $(GCC_BUILD) $(GCC_SRC) $(BINUTILS_BUILD) $(BINUTILS_SRC)
clean-toolchain-all:
rm -rf toolchain/*
.PHONY: toolchain toolchain_gcc toolchain_binutils

4
src/bootloader/stage1/boot.asm
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@ -373,8 +373,8 @@ msg_no_stage2: db 'Cant Find Stage 2!', ENDL, 0
file_stage2_bin: db 'STAGE2 BIN'
stage2_cluster: dw 0
STAGE2_LOAD_SEGMENT equ 0x2000
STAGE2_LOAD_OFFSET equ 0
STAGE2_LOAD_SEGMENT equ 0x0
STAGE2_LOAD_OFFSET equ 0x500
times 510-($-$$) db 0
dw 0AA55h

17
src/bootloader/stage2/Makefile
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@ -1,9 +1,8 @@
BUILD_DIR?=build/
ASM?=nasm
ASMFLAGS?=-f obj
CC16?=/usr/bin/watcom/binl/wcc
CFLAGS16?=-4 -d3 -s -wx -ms -zl -zq -za99 # -oneatxzh
LD16?=/usr/bin/watcom/binl/wlink
TARGET_ASMFLAGS += -f elf
TARGET_CFLAGS += -ffreestanding -nostdlib
TARGET_LIBS += -lgcc
TARGET_LINKFLAGS += -T linker.ld -nostdlib
SOURCES_C=$(wildcard *.c)
SOURCES_ASM=$(wildcard *.asm)
@ -17,13 +16,13 @@ all: stage2
stage2: $(BUILD_DIR)/stage2.bin
$(BUILD_DIR)/stage2.bin: $(OBJECTS_ASM) $(OBJECTS_C)
$(LD16) NAME $(BUILD_DIR)/stage2.bin FILE \{ $(OBJECTS_ASM) $(OBJECTS_C) \} OPTION MAP=$(BUILD_DIR)/stage2.map @linker.lnk
$(TARGET_LD) $(TARGET_LINKFLAGS) -Wl,-Map=$(BUILD_DIR)/stage2.map -o $@ $^ $(TARGET_LIBS)
$(BUILD_DIR)/stage2/c/%.obj: %.c always
$(CC16) $(CFLAGS16) -fo=$@ $<
$(TARGET_CC) $(TARGET_CFLAGS) -c -o $@ $<
$(BUILD_DIR)/stage2/asm/%.obj: %.asm always
$(ASM) $(ASMFLAGS) -o $@ $<
$(TARGET_ASM) $(TARGET_ASMFLAGS) -o $@ $<
always:
mkdir -p $(BUILD_DIR)/stage2/c

14
src/bootloader/stage2/ctype.c
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@ -1,14 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "ctype.h"
bool islower(char chr) {
return chr >= 'a' && chr <= 'z';
}
char toupper(char chr) {
return islower(chr) ? (chr - 'a' + 'A') : chr;
}

10
src/bootloader/stage2/ctype.h
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@ -1,10 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
#include "stdint.h"
bool islower(char chr);
char toupper(char chr);

48
src/bootloader/stage2/disk.c
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@ -1,48 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "disk.h"
#include "x86.h"
#include "stdio.h"
bool DISK_Initialize(DISK* disk, uint8_t driveNumber) {
uint8_t driveType;
uint16_t cylinders, sectors, heads;
if (!x86_Disk_GetDriveParams(disk->id, &driveType, &cylinders, &sectors, &heads))
return false;
disk->id = driveNumber;
disk->cylinders = cylinders + 1;
disk->heads = heads + 1;
disk->sectors = sectors;
return true;
}
void DISK_LBA2CHS(DISK* disk, uint32_t lba, uint16_t* cylinderOut, uint16_t* sectorOut, uint16_t* headOut) {
// sector = (LBA % sectors per track + 1)
*sectorOut = lba % disk->sectors +1;
// cylinder = (LBA / sects per track / heads)
*cylinderOut = (lba / disk->sectors) / disk->heads;
// head = (LBA / sects per track % heads)
*headOut = (lba / disk->sectors) % disk->heads;
}
bool DISK_ReadSectors(DISK* disk, uint32_t lba, uint8_t sectors, void far* dataOut) {
uint16_t cylinder, sector, head;
DISK_LBA2CHS(disk, lba, &cylinder, &sector, &head);
for (int i = 0; i < 3; i++) {
if (x86_Disk_Read(disk->id, cylinder, sector, head, sectors, dataOut))
return true;
x86_Disk_Reset(disk->id);
}
return false;
}

19
src/bootloader/stage2/disk.h
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@ -1,19 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
#include "stdint.h"
typedef struct {
uint8_t id;
uint16_t cylinders;
uint16_t sectors;
uint16_t heads;
} DISK;
bool DISK_Initialize(DISK* disk, uint8_t driveNumber);
bool DISK_ReadSectors(DISK* disk, uint32_t lba, uint8_t sectors, void far* dataOut);

175
src/bootloader/stage2/entry.asm Normal file
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@ -0,0 +1,175 @@
;/////////////////////;
;Nanite OS ;
;COPYRIGHT (C) 2024 ;
;Tyler McGurrin ;
;/////////////////////;
bits 16
section .entry
extern __bss_start
extern __end
extern start
global entry
entry:
cli
; save boot drive
mov [g_BootDrive], dl
; setup stack
mov ax, ds
mov ss, ax
mov sp, 0xFFF0
mov bp, sp
; switch to PMODE
call EnableA20
call LoadGDT
; set PMODE enable flag in CR0
mov eax, CR0
or al, 1
mov cr0, eax
; far jmp into PMODE
jmp dword 08h:.pmode
.pmode:
; we are now in protected mode!
[bits 32]
; 6 - setup segment registers
mov ax, 0x10
mov ds, ax
mov ss, ax
mov al, 0
cld
rep stosb
; clear BSS (uninit data)
mov edi, __bss_start
mov ecx, __end
sub ecx, edi
xor edx, edx
mov dl, [g_BootDrive]
push edx
call start
cli
hlt
EnableA20:
[bits 16]
; disable keyboard
call A20WaitInput
mov al, KbdControllerDisableKeyboard
out KbdControllerCommandPort, al
; read control output port
call A20WaitInput
mov al, KbdControllerReadCtrlOutputPort
out KbdControllerCommandPort, al
call A20WaitOutput
in al, KbdControllerDataPort
push eax
; write control output port
call A20WaitInput
mov al, KbdControllerWriteCtrlOutputPort
out KbdControllerCommandPort, al
call A20WaitInput
pop eax
or al, 2 ; bit 2 = A20 bit
out KbdControllerDataPort, al
; enable keyboard
call A20WaitInput
mov al, KbdControllerEnableKeyboard
out KbdControllerCommandPort, al
call A20WaitInput
ret
A20WaitInput:
[bits 16]
; wait until status bit 2 (input buffer) is 0
; by reading from command port, we read status byte
in al, KbdControllerCommandPort
test al, 2
jnz A20WaitInput
ret
A20WaitOutput:
[bits 16]
; wait until status bit 1 (output buffer) is 1 so it can be read
in al, KbdControllerCommandPort
test al, 1
jz A20WaitOutput
ret
LoadGDT:
[bits 16]
lgdt [g_GDTDesc]
ret
KbdControllerDataPort equ 0x60
KbdControllerCommandPort equ 0x64
KbdControllerDisableKeyboard equ 0xAD
KbdControllerEnableKeyboard equ 0xAE
KbdControllerReadCtrlOutputPort equ 0xD0
KbdControllerWriteCtrlOutputPort equ 0xD1
ScreenBuffer equ 0xB8000
g_GDT: ; NULL descriptor
dq 0
; 32-bit code segment
dw 0FFFFh ; limit (bits 0-15) = 0xFFFFF for full 32-bit range
dw 0 ; base (bits 0-15) = 0x0
db 0 ; base (bits 16-23)
db 10011010b ; access (present, ring 0, code segment, executable, direction 0, readable)
db 11001111b ; granularity (4k pages, 32-bit pmode) + limit (bits 16-19)
db 0 ; base high
; 32-bit data segment
dw 0FFFFh ; limit (bits 0-15) = 0xFFFFF for full 32-bit range
dw 0 ; base (bits 0-15) = 0x0
db 0 ; base (bits 16-23)
db 10010010b ; access (present, ring 0, data segment, executable, direction 0, writable)
db 11001111b ; granularity (4k pages, 32-bit pmode) + limit (bits 16-19)
db 0 ; base high
; 16-bit code segment
dw 0FFFFh ; limit (bits 0-15) = 0xFFFFF
dw 0 ; base (bits 0-15) = 0x0
db 0 ; base (bits 16-23)
db 10011010b ; access (present, ring 0, code segment, executable, direction 0, readable)
db 00001111b ; granularity (1b pages, 16-bit pmode) + limit (bits 16-19)
db 0 ; base high
; 16-bit data segment
dw 0FFFFh ; limit (bits 0-15) = 0xFFFFF
dw 0 ; base (bits 0-15) = 0x0
db 0 ; base (bits 16-23)
db 10010010b ; access (present, ring 0, data segment, executable, direction 0, writable)
db 00001111b ; granularity (1b pages, 16-bit pmode) + limit (bits 16-19)
db 0 ; base high
g_GDTDesc: dw g_GDTDesc - g_GDT - 1 ; limit = size of GDT
dd g_GDT ; address of GDT
g_BootDrive: db 0

322
src/bootloader/stage2/fat.c
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@ -1,322 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "fat.h"
#include "stdio.h"
#include "memdefs.h"
#include "utility.h"
#include "string.h"
#include "memory.h"
#include "ctype.h"
#define SECTOR_SIZE 512
#define MAX_PATH_SIZE 256
#define MAX_FILE_HANDLES 10
#define ROOT_DIRECTORY_HANDLE -1
#pragma pack(push,1)
typedef struct
{
uint8_t BootJumpInstruction[3];
uint8_t OemIdentifier[8];
uint16_t BytesPerSector;
uint8_t SectorsPerCluster;
uint16_t ReservedSectors;
uint8_t FatCount;
uint16_t DirEntryCount;
uint16_t TotalSectors;
uint8_t MediaDescriptorType;
uint16_t SectorsPerFat;
uint16_t SectorsPerTrack;
uint16_t Heads;
uint32_t HiddenSectors;
uint32_t LargeSectorCount;
//Extended Boot Record
uint8_t DriveNumber;
uint8_t _Reserved;
uint8_t Signature;
uint32_t VolumeId; //Serial Can be whatever
uint8_t VolumeLabel[11]; //11 Bytes MUST Be padded with spaces!
uint8_t SystemId[8]; //8 Bytes padded with spaces (use MSWIN4.1 for best compatibility!)
} FAT_BootSector;
#pragma pack(pop)
typedef struct {
FAT_File Public;
bool Opened;
uint32_t FirstCluster;
uint32_t CurrentCluster;
uint32_t CurrentSectorInCluster;
uint8_t Buffer[SECTOR_SIZE];
} FAT_FileData;
typedef struct {
union {
FAT_BootSector BootSector;
uint8_t BootSectorBytes[SECTOR_SIZE];
} BS;
FAT_FileData RootDirectory;
FAT_FileData OpenedFiles[MAX_FILE_HANDLES];
} FAT_Data;
static FAT_Data far* g_Data;
static uint8_t far* g_Fat = NULL;
static uint32_t g_DataSectionLba;
bool FAT_ReadBootSector(DISK* disk) {
return DISK_ReadSectors(disk, 0, 1, &g_Data->BS.BootSectorBytes);
}
bool FAT_ReadFat(DISK* disk)
{
return DISK_ReadSectors(disk, g_Data->BS.BootSector.ReservedSectors, g_Data->BS.BootSector.SectorsPerFat, g_Fat);
}
bool FAT_Initialize(DISK* disk) {
g_Data = (FAT_Data far*)MEMORY_FAT_ADDR;
// read bootsector
if (!FAT_ReadBootSector(disk)) {
printf("FAT: Bootsector Read Failed!\r\n");
return false;
}
// read FAT
g_Fat = (uint8_t far*)(g_Data + sizeof(FAT_Data));
uint32_t fatSize = g_Data->BS.BootSector.BytesPerSector * g_Data->BS.BootSector.SectorsPerFat;
if(sizeof(FAT_Data) + fatSize >= MEMORY_FAT_SIZE) {
printf("FAT: Not Enough Memory to Read FAT!\r\nNeeded %u, Only Have %u\r\n", sizeof(FAT_Data) + fatSize, MEMORY_FAT_SIZE);
return false;
}
if (!FAT_ReadFat(disk)) {
printf("FAT: Failed to Read FAT!\r\n");
return false;
}
// open root dir
uint32_t rootDirLba = g_Data->BS.BootSector.ReservedSectors + g_Data->BS.BootSector.SectorsPerFat * g_Data->BS.BootSector.FatCount;
uint32_t rootDirSize = sizeof(FAT_DirectoryEntry) * g_Data->BS.BootSector.DirEntryCount;
g_Data->RootDirectory.Public.Handle = ROOT_DIRECTORY_HANDLE;
g_Data->RootDirectory.Public.IsDirectory = true;
g_Data->RootDirectory.Public.Position = 0;
g_Data->RootDirectory.Public.Size = sizeof(FAT_DirectoryEntry) * g_Data->BS.BootSector.DirEntryCount;
g_Data->RootDirectory.Opened = true;
g_Data->RootDirectory.FirstCluster = rootDirLba;
g_Data->RootDirectory.CurrentCluster = 0;
g_Data->RootDirectory.CurrentSectorInCluster = 0;
if (!DISK_ReadSectors(disk, rootDirLba, 1, g_Data->RootDirectory.Buffer)) {
printf("FAT: Failed to Read Root Directory!\r\n");
return false;
}
//calculate data
uint32_t rootDirSectors = (rootDirSize + g_Data->BS.BootSector.BytesPerSector - 1) / g_Data->BS.BootSector.BytesPerSector;
g_DataSectionLba = rootDirLba + rootDirSectors;
// reset opened files
for (int i = 0; i < MAX_FILE_HANDLES; i++)
g_Data->OpenedFiles[i].Opened = false;
return true;
}
uint32_t FAT_ClusterToLba(uint32_t cluster) {
return g_DataSectionLba + (cluster -2) * g_Data->BS.BootSector.SectorsPerCluster;
}
FAT_File far* FAT_OpenEntry(DISK* disk, FAT_DirectoryEntry* entry) {
// find empty handle
int handle = -1;
for (int i = 0; i < MAX_FILE_HANDLES && handle < 0; i++) {
if (!g_Data->OpenedFiles[i].Opened)
handle = i;
}
// out of handles
if (handle < 0) {
printf("FAT: Out of File Handles!\r\n");
return false;
}
// setup vars
FAT_FileData far* fd = &g_Data->OpenedFiles[handle];
fd->Public.Handle = handle;
fd->Public.IsDirectory = (entry->Attributes & FAT_ATTRIBUTE_DIRECTORY) != 0;
fd->Public.Position = 0;
fd->Public.Size = entry->Size;
fd->FirstCluster = entry->FirstClusterLow + ((uint32_t)entry->FirstClusterHigh << 16);
fd->CurrentCluster = fd->FirstCluster;
fd->CurrentSectorInCluster = 0;
if (!DISK_ReadSectors(disk, FAT_ClusterToLba(fd->CurrentCluster), 1, fd->Buffer)) {
printf("FAT: Read Error!\r\n");
return false;
}
fd->Opened = true;
return &fd->Public;
}
uint32_t FAT_NextCluster(uint32_t currentCluster) {
uint32_t fatIndex = currentCluster * 3 / 2;
if (currentCluster % 2 == 0)
return (*(uint16_t far*)(g_Fat + fatIndex)) & 0x0FFF;
else
return (*(uint16_t far*)(g_Fat + fatIndex)) >> 4;
}
uint32_t FAT_Read(DISK* disk, FAT_File far* file, uint32_t byteCount, void* dataOut) {
// get file data
FAT_FileData far* fd = (file->Handle == ROOT_DIRECTORY_HANDLE)
? &g_Data->RootDirectory
: &g_Data->OpenedFiles[file->Handle];
uint8_t* u8DataOut = (uint8_t*)dataOut;
// don't read past EOF
if (!fd->Public.IsDirectory)
byteCount = min(byteCount, fd->Public.Size - fd->Public.Position);
while (byteCount > 0) {
uint32_t leftInBuffer = SECTOR_SIZE - (fd->Public.Position % SECTOR_SIZE);
uint32_t take = min(byteCount, leftInBuffer);
memcpy(u8DataOut, fd->Buffer + fd->Public.Position % SECTOR_SIZE, take);
u8DataOut += take;
fd->Public.Position += take;
byteCount -= take;
// see if we need to read more data
if (leftInBuffer == take) {
// root dir handler
if (fd->Public.Handle == ROOT_DIRECTORY_HANDLE) {
++fd->CurrentCluster;
// read next sect.
if (!DISK_ReadSectors(disk, fd->CurrentCluster, 1, fd->Buffer)) {
printf("FAT: Read Error!\r\n");
break;
}
}
else {
// read next sect.
if (++fd->CurrentSectorInCluster >= g_Data->BS.BootSector.SectorsPerCluster) {
// calc next cluster & sect. to read
fd->CurrentSectorInCluster = 0;
fd->CurrentCluster = FAT_NextCluster;
}
if (fd->CurrentCluster >= 0x0FF8) {
// mark EOF
fd->Public.Size = fd.Public.Position;
break;
}
// read next sect.
if (!DISK_ReadSectors(disk, FAT_ClusterToLba(fd->CurrentCluster) + fd->CurrentSectorInCluster, 1, fd->Buffer)) {
printf("FAT: Read Error!\r\n");
break;
}
}
}
}
return u8DataOut - (uint8_t*)dataOut;
}
bool FAT_ReadEntry(DISK* disk, FAT_File far* file, FAT_DirectoryEntry* dirEntry) {
return FAT_Read(disk, file, sizeof(FAT_DirectoryEntry), dirEntry) == sizeof(FAT_DirectoryEntry);
}
void FAT_Close(FAT_File far* file) {
if (file->Handle == ROOT_DIRECTORY_HANDLE) {
file->Position = 0;
g_Data->RootDirectory.CurrentCluster = g_Data->RootDirectory.FirstCluster;
}
else {
g_Data->OpenedFiles[file->Handle].Opened = false;
}
}
bool FAT_FindFile(DISK* disk, FAT_File far* file, const char* name, FAT_DirectoryEntry* entryOut) {
char fatName[11];
FAT_DirectoryEntry entry;
// convert from name to fat name
memset(fatName, ' ', sizeof(fatName));
const char* ext = strchr(name, '.');
if (ext == NULL)
ext = name + 11;
for (int i = 0; i < 8 && name[i] && name + i < ext; i++)
fatName[i] = toupper(name[i]);
if (ext != NULL) {
for (int i = 0; i < 3 && ext[i + 1]; i++)
fatName[i + 8] = toupper(ext[i + 1]);
}
while (FAT_ReadEntry(disk, file, &entry)) {
if (memcmp(fatName, entry.Name, 11) == 0) {
*entryOut = entry;
return true;
}
}
return false;
}
FAT_File far* FAT_Open(DISK* disk, const char* path) {
char name[MAX_PATH_SIZE];
// ignore leading slash
if (path[0] == '/')
path++;
FAT_File far* current = &g_Data->RootDirectory.Public;
while (*path) {
// extract next file name from path
bool isLast = false;
const char* delim = strchr(path, '/');
if (delim != NULL) {
memcpy(name, path, delim - path);
name[delim - path + 1] = '\0';
path = delim + 1;
}
else {
unsigned len = strlen(path);
memcpy(name, path, len);
name[len + 1] = '\0';
path += len;
bool isLast = true;
}
// find directory entry in current dir
FAT_DirectoryEntry entry;
if (FAT_FindFile(disk, current, name, &entry)) {
FAT_Close(current);
// check if DIR
if (!isLast && entry.Attributes & FAT_ATTRIBUTE_DIRECTORY == 0) {
printf("FAT: %s is NOT a Directory!\r\n", name);
return NULL;
}
// open new DIR entry
current = FAT_OpenEntry(disk, &entry);
}
else {
FAT_Close(current);
printf("FAT: %s NOT Found!", name);
return NULL;
}
}
return current;
}

51
src/bootloader/stage2/fat.h
View File

@ -1,51 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
#include "stdint.h"
#include "disk.h"
#pragma pack(push, 1)
typedef struct
{
uint8_t Name[11];
uint8_t Attributes;
uint8_t _Reserved;
uint8_t CreatedTimeTenths;
uint16_t CreatedTime;
uint16_t CreatedDate;
uint16_t AccessedDate;
uint16_t FirstClusterHigh;
uint16_t ModifiedTime;
uint16_t ModifiedDate;
uint16_t FirstClusterLow;
uint32_t Size;
} FAT_DirectoryEntry;
#pragma pack(pop)
typedef struct {
int Handle;
bool IsDirectory;
uint32_t Position;
uint32_t Size;
} FAT_File;
enum FAT_Attributes {
FAT_ATTRIBUTE_READ_ONLY = 0x01,
FAT_ATTRIBUTE_HIDDEN = 0x02,
FAT_ATTRIBUTE_SYSTEM = 0x04,
FAT_ATTRIBUTE_VOLUME_ID = 0x08,
FAT_ATTRIBUTE_DIRECTORY = 0x10,
FAT_ATTRIBUTE_ARCHIVE = 0x20,
FAT_ATTRIBUTE_LFN = FAT_ATTRIBUTE_READ_ONLY | FAT_ATTRIBUTE_HIDDEN | FAT_ATTRIBUTE_SYSTEM | FAT_ATTRIBUTE_VOLUME_ID
};
bool FAT_Initialize(DISK* disk);
FAT_File far* FAT_Open(DISK* disk, const char* path);
uint32_t FAT_Read(DISK* disk, FAT_File far* file, uint32_t byteCount, void* dataOut);
bool FAT_ReadEntry(DISK* disk, FAT_File far* file, FAT_DirectoryEntry* dirEntry);
void FAT_Close(FAT_File far* file);

15
src/bootloader/stage2/linker.ld Normal file
View File

@ -0,0 +1,15 @@
ENTRY(entry)
OUTPUT_FORMAT("binary")
phys = 0x00000500;
SECTIONS {
. = phys;
.entry : { __entry_start = .; *(.entry) }
.text : { __text_start = .; *(.text) }
.data : { __data_start = .; *(.data) }
.rodata : { __rodata_start = .; *(.rodata) }
.bss : { __bss_start = .; *(.bss) }
__end = .;
}

12
src/bootloader/stage2/linker.lnk
View File

@ -1,12 +0,0 @@
FORMAT RAW BIN
OPTION QUIET,
NODEFAULTLIBS,
START=entry,
VERBOSE,
OFFSET=0,
STACK=0x200
ORDER
CLNAME CODE
SEGMENT _ENTRY
SEGMENT _TEXT
CLNAME DATA

28
src/bootloader/stage2/main.asm
View File

@ -1,28 +0,0 @@
;/////////////////////;
;Nanite OS ;
;COPYRIGHT (C) 2024 ;
;Tyler McGurrin ;
;/////////////////////;
bits 16
section _ENTRY class=CODE
extern _cstart_
global entry
entry:
cli
; setup stack
mov ax, ds
mov ss, ax
mov sp, 0
mov bp, sp
sti
; expect boot drive in dl, send it as argument to cstart function
xor dh, dh
push dx
call _cstart_
cli
hlt

99
src/bootloader/stage2/main.c
View File

@ -3,64 +3,67 @@
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "stdint.h"
#include <stdint.h>
#include "stdio.h"
#include "disk.h"
#include "fat.h"
// #include "disk.h"
// #include "fat.h"
void far* g_data = (void far*)0x00500200;
#define LOGO " _ _____ _ __________________\r\n / | / / | / | / / _/_ __/ ____/\r\n / |/ / /| | / |/ // / / / / __/ \r\n / /| / ___ |/ /| // / / / / /___ \r\n\\/_/ |_/_/ |_/_/ |_/___/ /_/ /_____/ \r\n"
// void far* g_data = (void far*)0x00500200;
#define LOGO " _ _____ _ __________________\n / | / / | / | / / _/_ __/ ____/\n / |/ / /| | / |/ // / / / / __/ \n / /| / ___ |/ /| // / / / / /___ \n\\/_/ |_/_/ |_/_/ |_/___/ /_/ /_____/ \n"
#define VERSION "v0.0.1"
void _cdecl cstart_(uint16_t bootDrive) {
void __attribute__((cdecl)) start(uint16_t bootDrive) {
clrscr();
printf("%s", LOGO);
printf(" %s\r\n--------------------------------------\r\n", VERSION);
printf(" %s\n--------------------------------------\n", VERSION);
for(;;);
printf("Initializing FAT Driver...");
DISK disk;
if (!DISK_Initialize(&disk, bootDrive)) {
printf("Failed!\r\nDisk Initialization Error\r\n");
goto end;
}
// printf("Initializing FAT Driver...");
// DISK disk;
// if (!DISK_Initialize(&disk, bootDrive)) {
// printf("Failed!\nDisk Initialization Error\n");
// goto end;
// }
DISK_ReadSectors(&disk, 19, 1, g_data);
// DISK_ReadSectors(&disk, 19, 1, g_data);
if (!FAT_Initialize(&disk)) {
printf("Failed!\r\nDisk Initialization Error\r\n");
goto end;
}
printf("Done!\r\n");
// printf("Listing Root DIR...\r\n");
// // browse files in root
FAT_File far* fd = FAT_Open(&disk, "/");
FAT_DirectoryEntry entry;
int i = 0;
// while (FAT_ReadEntry(&disk, fd, &entry) && i++ < 5) {
// printf(" ");
// for (int i = 0; i < 11; i++)
// putc(entry.Name[i]);
// printf("\r\n");
// }
// FAT_Close(fd);
// if (!FAT_Initialize(&disk)) {
// printf("Failed!\nDisk Initialization Error\n");
// goto end;
// }
// printf("Done!\n");
// // printf("Listing Root DIR...\n");
// // // browse files in root
// FAT_File far* fd = FAT_Open(&disk, "/");
// FAT_DirectoryEntry entry;
// int i = 0;
// // while (FAT_ReadEntry(&disk, fd, &entry) && i++ < 5) {
// // printf(" ");
// // for (int i = 0; i < 11; i++)
// // putc(entry.Name[i]);
// // printf("\n");
// // }
// // FAT_Close(fd);
printf("Testing FAT Driver...");
// read test.txt
char buffer[100];
uint32_t read;
fd = FAT_Open(&disk, "misc/test.txt");
while ((read = FAT_Read(&disk, fd, sizeof(buffer), buffer)))
{
for (uint32_t i = 0; i < read; i++)
{
if (buffer[i] == '\n')
putc('\r');
putc(buffer[i]);
}
}
FAT_Close(fd);
// printf("Testing FAT Driver...");
// // read test.txt
// char buffer[100];
// uint32_t read;
// fd = FAT_Open(&disk, "misc/test.txt");
// while ((read = FAT_Read(&disk, fd, sizeof(buffer), buffer)))
// {
// for (uint32_t i = 0; i < read; i++)
// {
// if (buffer[i] == '\n')
// putc('');
// putc(buffer[i]);
// }
// }
// FAT_Close(fd);
end:
for (;;);
// end:
// for (;;);
}

24
src/bootloader/stage2/memdefs.h
View File

@ -1,24 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
// 0x00000000 - 0x000003FF - interrupt vector table
// 0x00000400 - 0x000004FF - BIOS data area
#define MEMORY_MIN 0x00000500
#define MEMORY_MAX 0x00080000
// 0x00000500 - 0x00010500 - FAT driver
#define MEMORY_FAT_ADDR ((void far*)0x00500000) // segment:offset (SSSSOOOO)
#define MEMORY_FAT_SIZE 0x00010000
// 0x00020000 - 0x00030000 - stage2
// 0x00030000 - 0x00080000 - free
// 0x00080000 - 0x0009FFFF - Extended BIOS data area
// 0x000A0000 - 0x000C7FFF - Video
// 0x000C8000 - 0x000FFFFF - BIOS

36
src/bootloader/stage2/memory.c
View File

@ -1,36 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "memory.h"
void far* memcpy(void far* dst, const void far* src, uint16_t num) {
uint8_t far* u8Dst = (uint8_t far *)dst;
const uint8_t far* u8Src = (const uint8_t far *)src;
for (uint16_t i = 0; i < num; i++)
u8Dst[i] = u8Src[i];
return dst;
}
void far* memset (void far * ptr, int value, uint16_t num) {
uint8_t far* u8Ptr = (uint8_t far *)ptr;
for (uint16_t i = 0; i < num; i++)
u8Ptr[i] = (uint8_t)value;
return ptr;
}
int memcmp(const void far* ptr1, const void far * ptr2, uint16_t num) {
const uint8_t far* u8Ptr1 = (const uint8_t far *)ptr1;
const uint8_t far* u8Ptr2 = (const uint8_t far *)ptr2;
for (uint16_t i = 0; i < num; i++)
if (u8Ptr1[i] != u8Ptr2[i])
return 1;
return 0;
}

11
src/bootloader/stage2/memory.h
View File

@ -1,11 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
#include "stdint.h"
void far* memcpy(void far* dst, const void far* src, uint16_t num);
void far* memset(void far* ptr, int value, uint16_t num);
int memcmp(const void far* ptr1, const void far * ptr2, uint16_t num);

24
src/bootloader/stage2/stdint.h
View File

@ -1,24 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
typedef signed char int8_t;
typedef unsigned char uint8_t;
typedef signed short int16_t;
typedef unsigned short uint16_t;
typedef signed long int int32_t;
typedef unsigned long int uint32_t;
typedef signed long long int int64_t;
typedef unsigned long long int uint64_t;
typedef uint8_t bool;
#define false 0
#define true 1
#define NULL ((void*)0)
#define min(a,b) ((a) < (b) ? (a) : (b))
#define max(a,b) ((a) > (b) ? (a) : (b))

290
src/bootloader/stage2/stdio.c
View File

@ -5,10 +5,107 @@
\*----------------*/
#include "stdio.h"
#include "x86.h"
#include <stdarg.h>
#include <stdbool.h>
const unsigned SCREEN_WIDTH = 80;
const unsigned SCREEN_HEIGHT = 25;
const uint8_t DEFAULT_COLOUR = 0x7;
uint8_t* g_ScreenBuffer = (uint8_t*)0xB8000;
int g_ScreenX = 0, g_ScreenY = 0;
void putchr(int x, int y, char c)
{
g_ScreenBuffer[2 * (y * SCREEN_WIDTH + x)] = c;
}
void putcolour(int x, int y, uint8_t colour)
{
g_ScreenBuffer[2 * (y * SCREEN_WIDTH + x) + 1] = colour;
}
char getchr(int x, int y)
{
return g_ScreenBuffer[2 * (y * SCREEN_WIDTH + x)];
}
uint8_t getcolour(int x, int y)
{
return g_ScreenBuffer[2 * (y * SCREEN_WIDTH + x) + 1];
}
void setcursor(int x, int y)
{
int pos = y * SCREEN_WIDTH + x;
x86_outb(0x3D4, 0x0F);
x86_outb(0x3D5, (uint8_t)(pos & 0xFF));
x86_outb(0x3D4, 0x0E);
x86_outb(0x3D5, (uint8_t)((pos >> 8) & 0xFF));
}
void clrscr()
{
for (int y = 0; y < SCREEN_HEIGHT; y++)
for (int x = 0; x < SCREEN_WIDTH; x++)
{
putchr(x, y, '\0');
putcolour(x, y, DEFAULT_COLOUR);
}
g_ScreenX =0; g_ScreenY = 0;
setcursor(g_ScreenX, g_ScreenY);
}
void scrollback(int lines)
{
for (int y = lines; y < SCREEN_HEIGHT; y++)
for (int x = 0; x < SCREEN_WIDTH; x++)
{
putchr(x, y - lines, getchr(x, y));
putcolour(x, y - lines, getcolour(x, y));
}
for (int y= SCREEN_HEIGHT - lines; y < SCREEN_HEIGHT; y++)
for (int x = 0; x < SCREEN_WIDTH; x++)
{
putchr(x, y - lines, getchr(x, y));
putcolour(x, y - lines, getcolour(x, y));
}
g_ScreenY -= lines;
}
void putc(char c)
{
x86_Video_WriteCharTeletype(c, 0);
switch (c)
{
case '\n':
g_ScreenX = 0;
g_ScreenY++;
break;
case '\t':
for (int i = 0; i < 4 - (g_ScreenX % 4); i++)
putc(' ');
break;
case '\r':
g_ScreenX = 0;
break;
default:
putchr(g_ScreenX, g_ScreenY, c);
g_ScreenX++;
break;
}
if (g_ScreenX >= SCREEN_WIDTH)
{
g_ScreenY++;
g_ScreenX = 0;
}
if (g_ScreenY >= SCREEN_HEIGHT)
scrollback(1);
setcursor(g_ScreenX, g_ScreenY);
}
void puts(const char* str)
@ -20,6 +117,39 @@ void puts(const char* str)
}
}
const char g_HexChars[] = "0123456789abcdef";
void printf_unsigned(unsigned long long number, int radix)
{
char buffer[32];
int pos = 0;
//number to ASCII conversion
do {
unsigned long long rem = number % radix;
number /= radix;
buffer[pos++] = g_HexChars[rem];
} while (number > 0);
//print number in reverse order
while (--pos >= 0)
putc(buffer[pos]);
}
void printf_signed(long long number, int radix)
{
if (number < 0)
{
putc('-');
printf_unsigned(-number, radix);
}
else printf_unsigned(number, radix);
}
#define PRINTF_STATE_NORMAL 0
#define PRINTF_STATE_LENGTH 1
#define PRINTF_STATE_LENGTH_SHORT 2
@ -32,17 +162,15 @@ void puts(const char* str)
#define PRINTF_LENGTH_LONG 3
#define PRINTF_LENGTH_LONG_LONG 4
void printf(const char* fmt, ...) {
va_list args;
va_start(args, fmt);
int* printf_number(int* argp, int length, bool sign, int radix);
void _cdecl printf(const char* fmt, ...) {
int* argp = (int*)&fmt;
int state= PRINTF_STATE_NORMAL;
int length = PRINTF_LENGTH_DEFAULT;
int radix = 10;
bool sign = false;
argp++;
bool number = false;
while (*fmt)
{
@ -93,39 +221,72 @@ void _cdecl printf(const char* fmt, ...) {
PRINTF_STATE_SPEC_:
switch (*fmt)
{
case 'c': putc((char)*argp);
argp++;
case 'c': putc((char)va_arg(args, int));
break;
case 's': puts(*(char***)argp);
argp++;
case 's': puts(va_arg(args, const char*));
break;
case '%': putc('%');
break;
case 'd':
case 'i': radix = 10; sign = true;
argp = printf_number(argp, length, sign, radix);
case 'i': radix = 10;
sign = true;
number = true;
break;
case 'u': radix = 10; sign = false;
argp = printf_number(argp, length, sign, radix);
case 'u': radix = 10; sign = false; number = true;
break;
case 'X':
case 'x':
case 'p': radix = 16; sign = false;
argp = printf_number(argp, length, sign, radix);
case 'p': radix = 16; sign = false; number = true;
break;
case 'o': radix = 8; sign = false;
argp = printf_number(argp, length, sign, radix);
case 'o': radix = 8; sign = false; number = true;
break;
//ignore invalid specifiers (specs)
default: break;
}
if (number)
{
if (sign)
{
switch (length)
{
case PRINTF_LENGTH_SHORT_SHORT:
case PRINTF_LENGTH_SHORT:
case PRINTF_LENGTH_DEFAULT:
printf_signed(va_arg(args, int), radix);
break;
case PRINTF_LENGTH_LONG:
printf_signed(va_arg(args, long), radix);
break;
case PRINTF_LENGTH_LONG_LONG:
printf_signed(va_arg(args, long long), radix);
break;
}
}
else
{
switch (length)
{
case PRINTF_LENGTH_SHORT_SHORT:
case PRINTF_LENGTH_SHORT:
case PRINTF_LENGTH_DEFAULT:
printf_unsigned(va_arg(args, unsigned int), radix);
break;
case PRINTF_LENGTH_LONG:
printf_unsigned(va_arg(args, unsigned long), radix);
break;
case PRINTF_LENGTH_LONG_LONG:
printf_unsigned(va_arg(args, unsigned long long), radix);
break;
}
}
}
//reset state
state = PRINTF_STATE_NORMAL;
@ -137,86 +298,21 @@ void _cdecl printf(const char* fmt, ...) {
fmt++;
}
va_end(args);
}
const char g_HexChars[] = "0123456789abcdef";
int* printf_number(int* argp, int length, bool sign, int radix)
void print_buffer(const char* msg, const void* buffer, uint32_t count)
{
char buffer[32];
unsigned long long number;
int number_sign = 1;
int pos = 0;
//process length
switch (length)
{
case PRINTF_LENGTH_SHORT_SHORT:
case PRINTF_LENGTH_SHORT:
case PRINTF_LENGTH_DEFAULT:
if (sign)
{
int n = *argp;
if (n < 0) {
n = -n;
number_sign = -1;
}
number = (unsigned long long)n;
}
else {
number = *(unsigned int*)argp;
}
argp++;
break;
case PRINTF_LENGTH_LONG:
if (sign)
{
long int n = *(long int*)argp;
if (n < 0) {
n = -n;
number_sign = -1;
}
number = (unsigned long long)n;
}
else {
number = *(unsigned long int*)argp;
}
argp += 2;
break;
case PRINTF_LENGTH_LONG_LONG:
if (sign)
{
long long int n = *(long long int*)argp;
if (n < 0) {
n = -n;
number_sign = -1;
}
number = (unsigned long long)n;
}
else {
number = *(unsigned long long*)argp;
}
argp += 4;
break;
}
//number to ASCII conversion
do {
uint32_t rem;
x86_div64_32(number, radix, &number, &rem);
buffer[pos++] = g_HexChars[rem];
} while (number > 0);
//add sign
if (sign && number_sign < 0) {
buffer[pos++] = '-';
}
//print number in reverse order
while (--pos >= 0)
putc(buffer[pos]);
return argp;
const uint8_t* u8Buffer = (const uint8_t*)buffer;
puts(msg);
for (uint16_t i = 0; i < count; i++)
{
putc(g_HexChars[u8Buffer[i] >> 4]);
putc(g_HexChars[u8Buffer[i] & 0xF]);
}
puts("\n");
}

5
src/bootloader/stage2/stdio.h
View File

@ -4,7 +4,10 @@
|Tyler McGurrin |
\*----------------*/
#pragma once
#include <stdint.h>
void clrscr();
void putc(char c);
void puts(const char* str);
void _cdecl printf(const char* fmt, ...);
void printf(const char* fmt, ...);
void print_buffer(const char* msg, const void* buffer, uint32_t count);

49
src/bootloader/stage2/string.c
View File

@ -1,49 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "string.h"
#include "stdint.h"
const char* strchr(const char* str, char chr) {
if (str == NULL)
return NULL;
while (*str) {
if (*str == chr)
return str;
++str;
}
return NULL;
}
char* strcpy(char* dst, const char* src) {
char* origDst = dst;
if (dst == NULL)
return NULL;
if (src == NULL) {
*dst = '\0';
return dst;
}
while (*src) {
*dst = *src;
++src;
++dst;
}
*dst = '\0';
return origDst;
}
unsigned strlen(const char* str) {
unsigned len = 0;
while (*str) {
++len; ++str;
}
return len;
}

10
src/bootloader/stage2/string.h
View File

@ -1,10 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
const char* strchr(const char* str, char chr);
char* strcpy(char* dst, const char* src);
unsigned strlen(const char* str);

14
src/bootloader/stage2/utility.c
View File

@ -1,14 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#include "utility.h"
uint32_t align(uint32_t number, uint32_t alignTo) {
if (alignTo == 0)
return number;
uint32_t rem = number % alignTo;
return (rem > 0) ? (number + alignTo - rem) : number;
}

9
src/bootloader/stage2/utility.h
View File

@ -1,9 +0,0 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
#include "stdint.h"
uint32_t align(uint32_t number, uint32_t alignTo);

324
src/bootloader/stage2/x86.asm
View File

@ -1,279 +1,77 @@
;/////////////////////;
;Nanite OS ;
;COPYRIGHT (C) 2024 ;
;Tyler McGurrin ;
;/////////////////////;
bits 16
%macro x86_EnterRealMode 0
[bits 32]
jmp work 18h:.pmode16
section _TEXT class=CODE
.pmode16:
[bits 16]
mov eax, cr0
and al, ~1
mov cr0, eax
jmp word 00h:.rmode
;
; U4D
;
; Operation: Unsigned 4 byte divide
; Inputs: DX;AX Dividend
; CX;BX Divisor
; Outputs: DX;AX Quotient
; CX;BX Remainder
; Volatile: none
;
global __U4D
__U4D:
shl edx, 16 ; dx to upper half of edx
mov dx, ax ; edx - dividend
mov eax, edx ; eax - dividend
xor edx, edx
.rmode:
mov ax, 0
mov ds, ax
mov ss, ax
shl ecx, 16 ; cx to upper half of ecx
mov cx, bx ; ecx - divisor
sti
div ecx ; eax - quot, edx - remainder
mov ebx, edx
mov ecx, edx
shr ecx, 16
%endmacro
mov edx, eax
shr edx, 16
%macro x86_EnterProtectedMode 0
cli
; set PMODE enable flag in CR0
mov eax, CR0
or al, 1
mov cr0, eax
ret
; far jmp into PMODE
jmp dword 08h:.pmode
;
; U4M
; Operation: integer four byte multiply
; Inputs: DX;AX integer M1
; CX;BX integer M2
; Outputs: DX;AX product
; Volatile: CX, BX destroyed
;
global __U4M
__U4M:
shl edx, 16 ; dx to upper half of edx
mov dx, ax ; m1 in edx
mov eax, edx ; m1 in eax
shl ecx, 16 ; cx to upper half of ecx
mov cx, bx ; m2 in ecx
mul ecx ; result in edx:eax (we only need eax)
mov edx, eax ; move upper half to dx
shr edx, 16
ret
;
; void _cdecl x86_div64_32(uint64_t dividend, uint32_t divisor, uint64_t* quotientOut, uint32_t* remainderOut);
;
global _x86_div64_32
_x86_div64_32:
; make new call frame
push bp ; save old call frame
mov bp, sp ; initialize new call frame
push bx
; divide upper 32 bits
mov eax, [bp + 8] ; eax <- upper 32 bits of dividend
mov ecx, [bp + 12] ; ecx <- divisor
xor edx, edx
div ecx ; eax - quot, edx - remainder
; store upper 32 bits of quotient
mov bx, [bp + 16]
mov [bx + 4], eax
; divide lower 32 bits
mov eax, [bp + 4] ; eax <- lower 32 bits of dividend
; edx <- old remainder
div ecx
; store results
mov [bx], eax
mov bx, [bp + 18]
mov [bx], edx
pop bx
; restore old call frame
mov sp, bp
pop bp
ret
;
; int 10h ah=0Eh
; args: character, page
;
global _x86_Video_WriteCharTeletype
_x86_Video_WriteCharTeletype:
.pmode:
; we are now in protected mode!
[bits 32]
; make new call frame
push bp ; save old call frame
mov bp, sp ; initialize new call frame
; 6 - setup segment registers
mov ax, 0x10
mov ds, ax
mov ss, ax
; save bx
push bx
; [bp + 0] - old call frame
; [bp + 2] - return address (small memory model => 2 bytes)
; [bp + 4] - first argument (character)
; [bp + 6] - second argument (page)
; note: bytes are converted to words (you can't push a single byte on the stack)
mov ah, 0Eh
mov al, [bp + 4]
mov bh, [bp + 6]
%endmacro
global x86_outb
x86_outb:
[bits 32]
mov dx, [esp + 4]
mov al, [esp + 8]
out dx, al
ret
global x86_inb
x86_inb:
[bits 32]
mov dx, [esp + 4]
xor eax, eax
in al, dx
ret
global x86_realmode_putc
x86_realmode_putc:
; setup stack frame
push ebp
mov ebp, esp
x86_EnterRealMode
mov al, [sp + 8]
mov ah, 0xe
int 10h
; restore bx
pop bx
x86_EnterProtectedMode
; restore old call frame
mov sp, bp
pop bp
mov esp, ebp
pop ebp
ret
;
; bool _cdecl x86_Disk_Reset(uint8_t drive);
;
global _x86_Disk_Reset
_x86_Disk_Reset:
; make new call frame
push bp ; save old call frame
mov bp, sp ; initialize new call frame
mov ah, 0
mov dl, [bp + 4] ; dl - drive
stc
int 13h
mov ax, 1
sbb ax, 0 ; 1 on success, 0 on fail
; restore old call frame
mov sp, bp
pop bp
ret
;
; bool _cdecl x86_Disk_Read(uint8_t drive,
; uint16_t cylinder,
; uint16_t sector,
; uint16_t head,
; uint8_t count,
; void far * dataOut);
;
global _x86_Disk_Read
_x86_Disk_Read:
; make new call frame
push bp ; save old call frame
mov bp, sp ; initialize new call frame
; save modified regs
push bx
push es
; setup args
mov dl, [bp + 4] ; dl - drive
mov ch, [bp + 6] ; ch - cylinder (lower 8 bits)
mov cl, [bp + 7] ; cl - cylinder to bits 6-7
shl cl, 6
mov al, [bp + 8] ; cl - sector to bits 0-5
and al, 3Fh
or cl, al
mov dh, [bp + 10] ; dh - head
mov al, [bp + 12] ; al - count
mov bx, [bp + 16] ; es:bx - far pointer to data out
mov es, bx
mov bx, [bp + 14]
; call int13h
mov ah, 02h
stc
int 13h
; set return value
mov ax, 1
sbb ax, 0 ; 1 on success, 0 on fail
; restore regs
pop es
pop bx
; restore old call frame
mov sp, bp
pop bp
ret
;
; bool _cdecl x86_Disk_GetDriveParams(uint8_t drive,
; uint8_t* driveTypeOut,
; uint16_t* cylindersOut,
; uint16_t* sectorsOut,
; uint16_t* headsOut);
;
global _x86_Disk_GetDriveParams
_x86_Disk_GetDriveParams:
; make new call frame
push bp ; save old call frame
mov bp, sp ; initialize new call frame
; save regs
push es
push bx
push si
push di
; call int13h
mov dl, [bp + 4] ; dl - disk drive
mov ah, 08h
mov di, 0 ; es:di - 0000:0000
mov es, di
stc
int 13h
; return
mov ax, 1
sbb ax, 0
; out params
mov si, [bp + 6] ; drive type from bl
mov [si], bl
mov bl, ch ; cylinders - lower bits in ch
mov bh, cl ; cylinders - upper bits in cl (6-7)
shr bh, 6
mov si, [bp + 8]
mov [si], bx
xor ch, ch ; sectors - lower 5 bits in cl
and cl, 3Fh
mov si, [bp + 10]
mov [si], cx
mov cl, dh ; heads - dh
mov si, [bp + 12]
mov [si], cx
; restore regs
pop di
pop si
pop bx
pop es
; restore old call frame
mov sp, bp
pop bp
ret

27
src/bootloader/stage2/x86.h
View File

@ -1,26 +1,5 @@
/*----------------*\
|Nanite OS |
|Copyright (C) 2024|
|Tyler McGurrin |
\*----------------*/
#pragma once
#include "stdint.h"
#include <stdint.h>
void _cdecl x86_div64_32(uint64_t dividend, uint32_t divisor, uint64_t* quotientOut, uint32_t* remainderOut);
void _cdecl x86_Video_WriteCharTeletype(char c, uint8_t page);
bool _cdecl x86_Disk_Reset(uint8_t drive);
bool _cdecl x86_Disk_Read(uint8_t drive,
uint16_t cylinder,
uint16_t sector,
uint16_t head,
uint8_t count,
void far * dataOut);
bool _cdecl x86_Disk_GetDriveParams(uint8_t drive,
uint8_t* driveTypeOut,
uint16_t* cylindersOut,
uint16_t* sectorsOut,
uint16_t* headsOut);
void __attribute__((cdecl)) x86_outb(uint16_t port, uint8_t value);
uint8_t __attribute__((cdecl)) x86_inb(uint16_t port);