Add support for a configuration file

Cargo.toml

@@ -13,6 +13,7 @@ edition = "2021"
 members = [
     "api",
     "common",
+    "common/config",
     "uefi",
     "bios/boot_sector",
     "bios/stage-*",
@@ -36,6 +37,7 @@ repository = "https://github.com/rust-osdev/bootloader"
 [workspace.dependencies]
 bootloader_api = { version = "0.11.0", path = "api" }
 bootloader-x86_64-common = { version = "0.11.0", path = "common" }
+bootloader-boot-config = { version = "0.11.0", path = "common/config" }
 bootloader-x86_64-bios-common = { version = "0.11.0", path = "bios/common" }
 
 [features]
@@ -49,7 +51,7 @@ fatfs = "0.3.4"
 tempfile = "3.3.0"
 mbrman = { version = "0.5.1", optional = true }
 gpt = { version = "3.0.0", optional = true }
-bootloader-x86_64-common = { version = "0.11.0", path = "common" }
+bootloader-boot-config = { version = "0.11.0", path = "common/config" }
 serde_json = "1.0.91"
 
 [dev-dependencies]

api/src/config.rs

@@ -30,7 +30,7 @@ pub struct BootloaderConfig {
     /// on the screen.
     #[deprecated(
         since = "0.11.1",
-        note = "This field is being obsolete because now it's at the JSON configuration file"
+        note = "The frame buffer is now configured through the `BootConfig` struct when creating the bootable disk image"
     )]
     pub frame_buffer: FrameBuffer,
 }

bios/stage-4/Cargo.toml

@@ -12,6 +12,7 @@ description = "Fourth BIOS stage of the `bootloader` crate"
 bootloader_api = { workspace = true }
 bootloader-x86_64-common = { workspace = true }
 bootloader-x86_64-bios-common = { workspace = true }
+bootloader-boot-config = { workspace = true }
 log = "0.4.14"
 x86_64 = "0.14.8"
 rsdp = "2.0.0"

bios/stage-4/src/main.rs

@@ -1,15 +1,14 @@
 #![no_std]
 #![no_main]
-#![allow(deprecated)]
 
 use crate::memory_descriptor::MemoryRegion;
 use bootloader_api::info::{FrameBufferInfo, PixelFormat};
+use bootloader_boot_config::{BootConfig, LevelFilter};
 use bootloader_x86_64_bios_common::{BiosFramebufferInfo, BiosInfo, E820MemoryRegion};
 use bootloader_x86_64_common::RawFrameBufferInfo;
 use bootloader_x86_64_common::{
-    config::{BootConfig, LevelFilter},
-    legacy_memory_region::LegacyFrameAllocator,
-    load_and_switch_to_kernel, Kernel, PageTables, SystemInfo,
+    legacy_memory_region::LegacyFrameAllocator, load_and_switch_to_kernel, Kernel, PageTables,
+    SystemInfo,
 };
 use core::{cmp, slice};
 use usize_conversions::usize_from;
@@ -136,19 +135,21 @@ pub extern "C" fn _start(info: &mut BiosInfo) -> ! {
         }
     };
 
+    #[allow(deprecated)]
     if config.frame_buffer.minimum_framebuffer_height.is_none() {
         config.frame_buffer.minimum_framebuffer_height =
             kernel.config.frame_buffer.minimum_framebuffer_height;
     }
+    #[allow(deprecated)]
     if config.frame_buffer.minimum_framebuffer_width.is_none() {
         config.frame_buffer.minimum_framebuffer_width =
             kernel.config.frame_buffer.minimum_framebuffer_width;
     }
     let framebuffer_info = init_logger(
         info.framebuffer,
         config.log_level,
-        config.frame_buffer_logger_status,
-        config.serial_logger_status,
+        config.frame_buffer_logging,
+        config.serial_logging,
     );
 
     if let Some(err) = error_loading_config {

common/Cargo.toml

@@ -10,6 +10,7 @@ repository.workspace = true
 
 [dependencies]
 bootloader_api = { workspace = true }
+bootloader-boot-config = { workspace = true }
 conquer-once = { version = "0.3.2", default-features = false }
 spinning_top = "0.2.4"
 usize_conversions = "0.2.0"
@@ -19,8 +20,6 @@ raw-cpuid = "10.2.0"
 rand = { version = "0.8.4", default-features = false }
 rand_hc = "0.3.1"
 uart_16550 = "0.2.18"
-serde-json-core = "0.5.0"
-serde = { version = "1.0.152", default-features = false, features = ["derive"] }
 log = "0.4.17"
 
 [dependencies.noto-sans-mono-bitmap]

common/config/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "bootloader-boot-config"
+version.workspace = true
+edition = "2021"
+description = "The runtime configurations that are saved in a JSON file for the bootloader crate"
+license.workspace = true
+repository.workspace = true
+
+[dependencies]
+serde = { version = "1.0.152", default-features = false, features = ["derive"] }

common/src/config.rs → common/config/src/lib.rs

@@ -1,6 +1,8 @@
+#![no_std]
+
 use serde::{Deserialize, Serialize};
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Default)]
 pub struct BootConfig {
     /// Configuration for the frame buffer that can be used by the kernel to display pixels
     /// on the screen.
@@ -16,24 +18,13 @@ pub struct BootConfig {
     ///
     /// Enabled by default.
     #[serde(default = "default_logger_status")]
-    pub frame_buffer_logger_status: bool,
+    pub frame_buffer_logging: bool,
 
     /// Whether the bootloader should print log messages to the serial port when booting.
     ///
     /// Enabled by default.
     #[serde(default = "default_logger_status")]
-    pub serial_logger_status: bool,
-}
-
-impl Default for BootConfig {
-    fn default() -> Self {
-        Self {
-            frame_buffer: Default::default(),
-            log_level: Default::default(),
-            frame_buffer_logger_status: true,
-            serial_logger_status: true,
-        }
-    }
+    pub serial_logging: bool,
 }
 
 /// Configuration for the frame buffer used for graphical output.

common/src/lib.rs

@@ -2,15 +2,13 @@
 #![feature(step_trait)]
 #![deny(unsafe_op_in_unsafe_fn)]
 
-use crate::{
-    config::LevelFilter,
-    legacy_memory_region::{LegacyFrameAllocator, LegacyMemoryRegion},
-};
+use crate::legacy_memory_region::{LegacyFrameAllocator, LegacyMemoryRegion};
 use bootloader_api::{
     config::Mapping,
     info::{FrameBuffer, FrameBufferInfo, MemoryRegion, TlsTemplate},
     BootInfo, BootloaderConfig,
 };
+use bootloader_boot_config::LevelFilter;
 use core::{alloc::Layout, arch::asm, mem::MaybeUninit, slice};
 use level_4_entries::UsedLevel4Entries;
 use usize_conversions::FromUsize;
@@ -23,8 +21,6 @@ use x86_64::{
 };
 use xmas_elf::ElfFile;
 
-/// Provides a type with the runtime configurations that are saved in a JSON file.
-pub mod config;
 /// Provides a function to gather entropy and build a RNG.
 mod entropy;
 /// Provides a type that logs output as text to pixel-based framebuffers.

src/bios/mbr.rs

@@ -84,7 +84,7 @@ pub fn create_mbr_disk(
     assert_eq!(
         disk.stream_position()
             .context("failed to get disk image seek position")?,
-        <u32 as Into<u64>>::into(second_stage_start_sector * SECTOR_SIZE)
+        u64::from(second_stage_start_sector * SECTOR_SIZE)
     );
     io::copy(&mut second_stage, &mut disk)
         .context("failed to copy second stage binary to MBR disk image")?;

src/bios/mod.rs

@@ -1,6 +1,6 @@
 use crate::fat;
 use anyhow::Context;
-use bootloader_x86_64_common::config::BootConfig;
+use bootloader_boot_config::BootConfig;
 use std::io::Write;
 use std::{
     collections::BTreeMap,
@@ -30,14 +30,14 @@ impl BiosBoot {
         }
     }
 
-    /// Add a ramdisk file to the image
+    /// Add a ramdisk file to the image.
     pub fn set_ramdisk(&mut self, ramdisk_path: &Path) -> &mut Self {
         self.ramdisk = Some(ramdisk_path.to_owned());
         self
     }
 
-    /// Add a JSON configuration file to the disk image
-    pub fn set_config_file(&mut self, config: &BootConfig) -> &mut Self {
+    /// Configures the runtime behavior of the bootloader.
+    pub fn set_boot_config(&mut self, config: &BootConfig) -> &mut Self {
         self.config = Some(serde_json::to_string(&config).expect("failed to serialize BootConfig"));
         self
     }

src/lib.rs

@@ -16,7 +16,7 @@ pub use bios::BiosBoot;
 #[cfg(feature = "uefi")]
 pub use uefi::UefiBoot;
 
-pub use bootloader_x86_64_common::config::BootConfig;
+pub use bootloader_boot_config::BootConfig;
 
 const KERNEL_FILE_NAME: &str = "kernel-x86_64";
 const RAMDISK_FILE_NAME: &str = "ramdisk";

src/uefi/mod.rs

@@ -1,6 +1,6 @@
 use crate::fat;
 use anyhow::Context;
-use bootloader_x86_64_common::config::BootConfig;
+use bootloader_boot_config::BootConfig;
 use std::io::Write;
 use std::{
     collections::BTreeMap,
@@ -28,14 +28,14 @@ impl UefiBoot {
         }
     }
 
-    /// Add a ramdisk file to the disk image
+    /// Add a ramdisk file to the disk image.
     pub fn set_ramdisk(&mut self, ramdisk_path: &Path) -> &mut Self {
         self.ramdisk = Some(ramdisk_path.to_owned());
         self
     }
 
-    /// Add a JSON configuration file to the disk image
-    pub fn set_config_file(&mut self, config: &BootConfig) -> &mut Self {
+    /// Configures the runtime behavior of the bootloader.
+    pub fn set_boot_config(&mut self, config: &BootConfig) -> &mut Self {
         self.config = Some(serde_json::to_string(&config).expect("failed to serialize BootConfig"));
         self
     }

tests/config_file.rs

@@ -17,8 +17,8 @@ fn custom_options_boot() {
     let config = BootConfig {
         frame_buffer: Default::default(),
         log_level: Default::default(),
-        frame_buffer_logger_status: false,
-        serial_logger_status: true,
+        frame_buffer_logging: false,
+        serial_logging: true,
     };
     run_test_kernel_internal(
         env!("CARGO_BIN_FILE_TEST_KERNEL_CONFIG_FILE_basic_boot_broken_config_file"),

tests/runner/src/lib.rs

@@ -41,7 +41,7 @@ pub fn run_test_kernel_internal(
             uefi_builder.set_ramdisk(rdp);
         }
         if let Some(cfp) = config_file_path {
-            uefi_builder.set_config_file(cfp);
+            uefi_builder.set_boot_config(cfp);
         }
         uefi_builder.create_disk_image(&gpt_path).unwrap();
 
@@ -64,7 +64,7 @@ pub fn run_test_kernel_internal(
             bios_builder.set_ramdisk(rdp);
         }
         if let Some(cfp) = config_file_path {
-            bios_builder.set_config_file(cfp);
+            bios_builder.set_boot_config(cfp);
         }
         bios_builder.create_disk_image(&mbr_path).unwrap();
 

uefi/Cargo.toml

@@ -11,6 +11,7 @@ repository.workspace = true
 [dependencies]
 bootloader_api = { workspace = true }
 bootloader-x86_64-common = { workspace = true }
+bootloader-boot-config = { workspace = true }
 log = "0.4.14"
 uefi = "0.18.0"
 x86_64 = "0.14.8"

uefi/src/main.rs

@@ -2,13 +2,12 @@
 #![no_main]
 #![feature(abi_efiapi)]
 #![deny(unsafe_op_in_unsafe_fn)]
-#![allow(deprecated)]
 
 use crate::memory_descriptor::UefiMemoryDescriptor;
 use bootloader_api::info::FrameBufferInfo;
+use bootloader_boot_config::BootConfig;
 use bootloader_x86_64_common::{
-    config::BootConfig, legacy_memory_region::LegacyFrameAllocator, Kernel, RawFrameBufferInfo,
-    SystemInfo,
+    legacy_memory_region::LegacyFrameAllocator, Kernel, RawFrameBufferInfo, SystemInfo,
 };
 use core::{
     cell::UnsafeCell,
@@ -76,13 +75,12 @@ fn main_inner(image: Handle, mut st: SystemTable<Boot>) -> Status {
 
     let mut boot_mode = BootMode::Disk;
     let config_file = load_config_file(image, &mut st, boot_mode);
-    let config_file: Option<&[u8]> = match config_file {
-        Some(config) => Some(config),
-        None => None,
-    };
-
     let mut error_loading_config: Option<serde_json_core::de::Error> = None;
-    let mut config: BootConfig = match config_file.map(serde_json_core::from_slice).transpose() {
+    let mut config: BootConfig = match config_file
+        .as_deref()
+        .map(serde_json_core::from_slice)
+        .transpose()
+    {
         Ok(data) => data.unwrap_or_default().0,
         Err(err) => {
             error_loading_config = Some(err);
@@ -98,10 +96,12 @@ fn main_inner(image: Handle, mut st: SystemTable<Boot>) -> Status {
     }
     let kernel = kernel.expect("Failed to load kernel");
 
+    #[allow(deprecated)]
     if config.frame_buffer.minimum_framebuffer_height.is_none() {
         config.frame_buffer.minimum_framebuffer_height =
             kernel.config.frame_buffer.minimum_framebuffer_height;
     }
+    #[allow(deprecated)]
     if config.frame_buffer.minimum_framebuffer_width.is_none() {
         config.frame_buffer.minimum_framebuffer_width =
             kernel.config.frame_buffer.minimum_framebuffer_width;
@@ -545,8 +545,8 @@ fn init_logger(
         slice,
         info,
         config.log_level,
-        config.frame_buffer_logger_status,
-        config.serial_logger_status,
+        config.frame_buffer_logging,
+        config.serial_logging,
     );
 
     Some(RawFrameBufferInfo {