feat: working bootloader and basic kernel (just dyes screen green)

Bootloader/CMakeLists.txt

@@ -24,6 +24,7 @@ add_library(posix_uefi_lib OBJECT ${POSIX_UEFI_SOURCES})
 target_compile_options(posix_uefi_lib PRIVATE ${UEFI_COMPILE_OPTIONS})
 target_include_directories(posix_uefi_lib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/Source/uefi)
 
+
 add_executable(BOOTAA64 Source/main.c)
 target_compile_options(BOOTAA64 PRIVATE ${UEFI_COMPILE_OPTIONS})
 

Bootloader/Source/main.c

@@ -1,7 +1,144 @@
 #include "uefi/uefi.h" // IWYU pragma: keep
+#include "../../Common/bootinfo.h"
 
-int main() {
+void print(wchar_t* msg) {
-    printf("Meow!\n");
+    ST->ConOut->OutputString(ST->ConOut, msg);
-    while (1) __asm__ ("wfi");
+}
-    return 0;
+
+efi_status_t die() {
+    while(1) __asm__ volatile("wfi");
+    return EFI_ABORTED;
+}
+
+int compare_guid(efi_guid_t* a, efi_guid_t* b) {
+    uint8_t* p1 = (uint8_t*)a;
+    uint8_t* p2 = (uint8_t*)b;
+    for (int i = 0; i < 16; i++) {
+        if (p1[i] != p2[i]) return 0;
+    }
+    return 1;
+}
+
+int main()
+{
+    efi_gop_t* gop = NULL;
+    efi_guid_t gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+    ST->BootServices->LocateProtocol(&gop_guid, 0, (void**)&gop);
+
+    efi_guid_t dtb_guid = {0xb1b621d5, 0xf19c, 0x41a5, {0x83, 0x0b, 0xd9, 0x15, 0x2c, 0x69, 0xaa, 0xe0}};
+    void* dtbAddress = NULL;
+
+    for (uintn_t i = 0; i < ST->NumberOfTableEntries; i++) {
+        if (compare_guid(&ST->ConfigurationTable[i].VendorGuid, &dtb_guid)) {
+            dtbAddress = ST->ConfigurationTable[i].VendorTable;
+            break;
+        }
+    }
+
+    if (!dtbAddress) {
+        print(L"Failed to find DTB!\r\n");
+        return die();
+    }
+
+    efi_loaded_image_protocol_t* loaded_image;
+    efi_guid_t lip_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
+    gBS->HandleProtocol(IM, &lip_guid, (void**)&loaded_image);
+
+    efi_simple_file_system_protocol_t* fs;
+    efi_guid_t sfsp_guid = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
+    gBS->HandleProtocol(loaded_image->DeviceHandle, &sfsp_guid, (void**)&fs);
+
+    efi_file_handle_t* root;
+    fs->OpenVolume(fs, &root);
+
+    efi_file_handle_t* kernel_file;
+    uintn_t kinfo_size = 0;
+    efi_file_info_t* kfile_info = NULL;
+    efi_guid_t fi_guid = EFI_FILE_INFO_GUID;
+
+    efi_status_t status = root->Open(root, &kernel_file, L"ksOSKernel.bin", EFI_FILE_MODE_READ, 0);
+    if (EFI_ERROR(status)) {
+        print(L"Cant find ksOSKernel.bin\r\n");
+        return die();
+    }
+
+    status = kernel_file->GetInfo(kernel_file, &fi_guid, &kinfo_size, NULL);
+    if (status == EFI_BUFFER_TOO_SMALL) { 
+        gBS->AllocatePool(EfiLoaderData, kinfo_size, (void**)&kfile_info);
+        status = kernel_file->GetInfo(kernel_file, &fi_guid, &kinfo_size, kfile_info);
+    }
+
+    uint64_t kernel_size = kfile_info->FileSize;
+    uintn_t kernel_size_read = (uintn_t)kernel_size;
+    
+    uintn_t kernel_pages = (kernel_size + 0xFFF) / 0x1000;
+    efi_physical_address_t kernel_addr = 0; 
+    
+    status = gBS->AllocatePages(AllocateAnyPages, EfiLoaderData, kernel_pages, &kernel_addr);
+    if (EFI_ERROR(status)) {
+        print(L"Failed to allocate ANY memory for kernel!\r\n");
+        return die();
+    }
+
+    kernel_file->Read(kernel_file, &kernel_size_read, (void*)kernel_addr); \
+    printf("Kernel loaded at %p\r\n", (void*)kernel_addr);
+
+    Bootinfo* bootInfo = (Bootinfo*)malloc(sizeof(Bootinfo));
+    bootInfo->magic = BOOTINFO_MAGIC;
+
+    bootInfo->kernelInfo.kernelAddress = (void*)kernel_addr;
+    bootInfo->kernelInfo.kernelSize = kernel_size;
+
+    bootInfo->framebuffer.base = (BIUInt32*)gop->Mode->FrameBufferBase;
+    bootInfo->framebuffer.baseSize = gop->Mode->FrameBufferSize;
+    bootInfo->framebuffer.height = gop->Mode->Information->VerticalResolution;
+    bootInfo->framebuffer.width = gop->Mode->Information->HorizontalResolution;
+    bootInfo->framebuffer.pitch = gop->Mode->Information->PixelsPerScanLine;
+
+    bootInfo->dtb = dtbAddress;
+    printf("DTB located at: %p\r\n", (void*)dtbAddress);
+    
+    uintn_t map_size = 0;
+    efi_memory_descriptor_t *map = NULL;
+    uintn_t map_key;
+    uintn_t desc_size;
+    uint32_t desc_version;
+
+
+    print(L"Almost ready to jump :D. Working with memory map\r\n");
+
+    gBS->GetMemoryMap(&map_size, NULL, &map_key, &desc_size, &desc_version);
+    map_size += 4096;
+    // woah letsgoo
+    status = gBS->AllocatePool(EfiLoaderData, map_size, (void**)&map);
+    if (EFI_ERROR(status)) {
+        print(L"Failed to allocate pool\r\n");
+    }
+
+    do {
+        status = gBS->GetMemoryMap(&map_size, map, &map_key, &desc_size, &desc_version);
+        if (EFI_ERROR(status)) {
+            break;
+        }
+        
+        bootInfo->memoryMap.descriptorSize = desc_size;
+        bootInfo->memoryMap.descriptorVersion = desc_version;
+        bootInfo->memoryMap.mapSize = map_size;
+        bootInfo->memoryMap.mapKey = map_key;
+        bootInfo->memoryMap.map = map;
+
+        status = gBS->ExitBootServices(IM, map_key);
+        if (status == EFI_SUCCESS) {
+            break; // FUCK OFF;
+        }
+        map_size += 2 * desc_size; 
+    } while (EFI_ERROR(status));
+
+    typedef void (__attribute__((sysv_abi)) *kentry)(Bootinfo*);
+    kentry kmain = (kentry)kernel_addr;
+
+    kmain(bootInfo); // yay! :D
+
+
+    return EFI_SUCCESS;
 }

Bootloader/justfile

@@ -1,14 +1,14 @@
 BUILD_DIR := env_var_or_default("BUILD_DIR", justfile_directory() + "/.build") 
 TEMP_DIR := env_var_or_default("TEMP_DIR", BUILD_DIR + "/temp")
 build:
-    cmake -B {{TEMP_DIR}}/bootloader -S . \
+    cmake -B {{TEMP_DIR}}/Bootloader -S . \
           -DCMAKE_TOOLCHAIN_FILE=Source/cmake/aarch64-uefi.cmake \
           -DCMAKE_BUILD_TYPE=Release
 
-    cmake --build {{TEMP_DIR}}/bootloader
+    cmake --build {{TEMP_DIR}}/Bootloader
 
-    cp {{TEMP_DIR}}/bootloader/efi_bin/BOOTAA64.EFI {{BUILD_DIR}}/bootloader/BOOTAA64.EFI
+    cp {{TEMP_DIR}}/Bootloader/efi_bin/BOOTAA64.EFI {{BUILD_DIR}}/Bootloader/BOOTAA64.EFI
-    @echo "✅ Bootloader ready at: {{BUILD_DIR}}/bootloader/BOOTAA64.EFI"
+    @echo "✅ Bootloader ready at: {{BUILD_DIR}}/Bootloader/BOOTAA64.EFI"
 
 clean:
-    rm -rf {{TEMP_DIR}}/bootloader
+    rm -rf {{TEMP_DIR}}/Bootloader

Common/bootinfo.h

@@ -0,0 +1,35 @@
+#pragma once
+
+typedef unsigned int       BIUInt32;
+typedef unsigned long long BIUInt64; 
+
+typedef struct {
+    BIUInt32* base;
+    BIUInt64 baseSize;
+    BIUInt64 width;
+    BIUInt64 height;
+    BIUInt64 pitch;
+} BIFramebuffer;
+
+typedef struct {
+    void* map;             
+    BIUInt64 mapSize;       
+    BIUInt64 descriptorSize;
+    BIUInt32 mapKey;
+    BIUInt32 descriptorVersion;
+} BIMemoryMap;
+
+typedef struct {
+    BIUInt64 kernelSize;
+    void* kernelAddress;
+} BIKernelInfo;
+
+typedef struct {
+    BIUInt64 magic;
+    BIKernelInfo kernelInfo;
+    void* dtb;
+    BIMemoryMap memoryMap;
+    BIFramebuffer framebuffer;
+} Bootinfo;
+
+#define BOOTINFO_MAGIC 0x736F6E7961

Kernel/CMakeLists.txt

@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.10)
+project(MyShittyKernel LANGUAGES ASM C)
+
+if(NOT LLVM_BIN)
+    execute_process(COMMAND brew --prefix llvm OUTPUT_VARIABLE LLVM_PREFIX OUTPUT_STRIP_TRAILING_WHITESPACE)
+    set(LLVM_BIN "${LLVM_PREFIX}/bin")
+endif()
+
+set(CMAKE_C_COMPILER "${LLVM_BIN}/clang")
+set(CMAKE_ASM_COMPILER "${LLVM_BIN}/clang")
+set(LLVM_OBJCOPY "${LLVM_BIN}/llvm-objcopy")
+
+set(TARGET_TRIPLE aarch64-none-elf)
+add_compile_options(--target=${TARGET_TRIPLE} -ffreestanding -nostdlib -O0 -g)
+
+set(LINKER_SCRIPT ${CMAKE_CURRENT_SOURCE_DIR}/linker.ld)
+add_link_options(
+    --target=${TARGET_TRIPLE}
+    -fuse-ld=lld
+    -nostdlib
+    -static
+    -Wl,-T,${LINKER_SCRIPT}
+)
+
+add_executable(kernel.elf Source/entry.S)
+
+add_custom_command(TARGET kernel.elf POST_BUILD
+    COMMAND ${LLVM_OBJCOPY} -O binary kernel.elf kernel.bin
+    COMMENT "kernel.elf -> kernel.bin"
+)

Kernel/Source/entry.S

@@ -0,0 +1,22 @@
+.section .text.boot, "ax"
+.global _start
+
+_start:
+    add x1, x0, #64         // x1 = BIFramebuffer
+    ldr x2, [x1]            // x2 = base
+    ldr x3, [x1, #16]       // x3 = width
+    ldr x4, [x1, #24]       // x4 = height
+    
+    mul x5, x3, x4 
+    
+    mov w6, #0x00FF00
+    movk w6, #0x0000, lsl #16 
+
+fill_loop:
+    cbz x5, done
+    str w6, [x2], #4
+    sub x5, x5, #1
+    b fill_loop
+
+done:
+    b done

Kernel/justfile

@@ -0,0 +1,12 @@
+BUILD_DIR := env_var_or_default("BUILD_DIR", justfile_directory() + "/.build") 
+TEMP_DIR := env_var_or_default("TEMP_DIR", BUILD_DIR + "/temp")
+build:
+    cmake -B {{TEMP_DIR}}/Kernel -S .
+
+    cmake --build {{TEMP_DIR}}/Kernel
+
+    cp {{TEMP_DIR}}/Kernel/kernel.bin {{BUILD_DIR}}/Kernel/ksOSKernel.bin
+    @echo "✅ Kernel ready at: {{BUILD_DIR}}/Kernel/ksOSKernel.bin"
+
+clean:
+    rm -rf {{TEMP_DIR}}/Kernel

justfile

@@ -28,21 +28,24 @@ CPU := if ARCH_NAME == "aarch64" { "host" } else { "max" }
 
 export BUILD_DIR := justfile_directory() + "/.build"
 export TEMP_DIR  := BUILD_DIR + "/temp"
-export BOOT_BIN  := BUILD_DIR + "/bootloader/BOOTAA64.EFI"
+export BOOT_BIN  := BUILD_DIR + "/Bootloader/BOOTAA64.EFI"
 export IMG_FILE  := BUILD_DIR + "/ksOS.img"
 
 mod Bootloader
+mod Kernel
 
 _default:
     just --list
 
 _prep:
-    @mkdir -p {{BUILD_DIR}}/bootloader
+    @mkdir -p {{BUILD_DIR}}/Bootloader
-    @mkdir -p {{TEMP_DIR}}/bootloader
+    @mkdir -p {{TEMP_DIR}}/Bootloader
+    @mkdir -p {{BUILD_DIR}}/Kernel
 
 @build: _prep
     @echo "🛠️ Building everything..."
     just Bootloader build
+    just Kernel build
 
 @_image: build
     @echo "💾 Creating image..."
@@ -50,19 +53,21 @@ _prep:
     @mkfs.fat -F 32 {{IMG_FILE}} > /dev/null
     @mmd -i {{IMG_FILE}} ::/EFI ::/EFI/BOOT
     @mcopy -i {{IMG_FILE}} {{BOOT_BIN}} ::/EFI/BOOT/BOOTAA64.EFI
+    @mcopy -i {{IMG_FILE}} {{BUILD_DIR}}/Kernel/ksOSKernel.bin ::/ksOSKernel.bin
 
 @run: _image
     @echo "🚀 Launching..."
     qemu-system-aarch64 {{ACCEL}} \
-        -machine virt \
+        -machine virt,acpi=off \
         -cpu {{CPU}} \
         -m 512M \
-        -device virtio-gpu-pci \
+        -device ramfb \
         -display cocoa,show-cursor=on \
         -drive if=pflash,format=raw,readonly=on,file={{OVMF_ARM}} \
         -drive file={{IMG_FILE}},format=raw,if=none,id=hd0 \
         -device virtio-blk-device,drive=hd0 \
-        -serial mon:stdio
+        -serial stdio \
-
+        -monitor telnet:127.0.0.1:5555,server,nowait
+        
 @clean:
     rm -rf {{BUILD_DIR}}