Refactor boot and add placeholder kcmdline struct

framework/jinux-frame/src/boot/mod.rs

@@ -0,0 +1,78 @@
+//! The architecture-independent boot module, which provides a universal interface
+//! from the bootloader to the rest of the framework.
+//! 
+
+use crate::arch::boot::init_boot_args;
+
+pub mod kcmdline;
+use kcmdline::KCmdlineArg;
+
+pub mod memory_region;
+use self::memory_region::MemoryRegion;
+
+use alloc::{string::String, vec::Vec};
+use spin::Once;
+
+/// The boot crate can choose either providing the raw RSDP physical address or
+/// providing the RSDT/XSDT physical address after parsing RSDP.
+/// This is because bootloaders differ in such behaviors.
+#[derive(Copy, Clone, Debug)]
+pub enum BootloaderAcpiArg {
+    /// Physical address of the RSDP.
+    Rsdp(usize),
+    /// Address of RSDT provided in RSDP v1.
+    Rsdt(usize),
+    /// Address of XSDT provided in RSDP v2+.
+    Xsdt(usize),
+}
+
+/// The framebuffer arguments.
+#[derive(Copy, Clone, Debug)]
+pub struct BootloaderFramebufferArg {
+    pub address: usize,
+    pub width: usize,
+    pub height: usize,
+    /// Bits per pixel of the buffer.
+    pub bpp: usize,
+}
+
+// Use a macro to simplify coding.
+macro_rules! define_global_static_boot_arguments {
+    ( $( $lower:ident, $upper:ident, $typ:ty; )* ) => {
+        // Define statics and corresponding public get APIs.
+        $(
+            static $upper: Once<$typ> = Once::new();
+            /// Macro generated public get API.
+            pub fn $lower() -> &'static $typ {
+                $upper.get().unwrap()
+            }
+        )*
+        // Produce a init function call. The init function must
+        // be defined in the `arch::boot` module conforming to this
+        // definition.
+        fn arch_init_boot_args() {
+            init_boot_args( $( &$upper, )* );
+        }
+    };
+}
+
+// Define a series of static variable definitions and its APIs. The names in
+// each line are:
+//  1. The lowercase name of the variable, also the name of the get API;
+//  2. the uppercase name of the variable;
+//  3. the type of the variable.
+define_global_static_boot_arguments!(
+    bootloader_name, BOOTLOADER_NAME, String;
+    kernel_cmdline, KERNEL_CMDLINE, KCmdlineArg;
+    initramfs, INITRAMFS, &'static [u8];
+    acpi_arg, ACPI_ARG, BootloaderAcpiArg;
+    framebuffer_arg, FRAMEBUFFER_ARG, BootloaderFramebufferArg;
+    memory_regions, MEMORY_REGIONS, Vec<MemoryRegion>;
+);
+
+/// After initializing the boot module, the get functions could be called.
+/// The initialization must be done after the heap is set and before physical
+/// mappings are cancelled.
+pub fn init() {
+    arch_init_boot_args();
+}