feat: 添加对内核引导协议的抽象 (DragonOS-Community#913)

* 添加multiboot header

* head.S传参增加bootloader类型

* feat: 添加引导加载协议的抽象,并为multiboot2实现这个抽象.

* 把framebuffer的映射地址改为从early ioremap和mmio pool分配

* riscv64能运行

.vscode/settings.json

@@ -129,7 +129,6 @@
         "assert.h": "c",
         "sys_version.h": "c",
         "cmd.h": "c",
-        "sleep.h": "c",
         "net.h": "c",
         "cmd_test.h": "c",
         "cmpxchg.h": "c",

docs/kernel/boot/bootloader.md

@@ -1,12 +1,24 @@
 # 引导加载程序
 
-## 原理
+## X86_64
 
-  目前，DragonOS支持Legacy BIOS以及UEFI两种方式，进行启动引导。
+- [x] multiboot2
 
-  在`head.S`的头部包含了Multiboot2引导头，里面标志了一些Multiboot2相关的特定信息，以及一些配置命令。
+## RISC-V 64
 
-  在DragonOS的启动初期，会存储由GRUB2传来的magic number以及multiboot2_boot_info_addr。当系统进入`Start_Kernel`函数之后，将会把这两个信息保存到multiboot2驱动程序之中。信息的具体含义请参照Multiboot2 Specification进行理解，该部分难度不大，相信读者经过思考能理解其中的原理。
+DragonOS在RISC-V 64上，启动流程为：
+
+opensbi --> uboot --> DragonStub --> kernel
+
+这个启动流程，使得DragonOS内核与具体的硬件板卡解耦，能够以同一个二进制文件，在不同的硬件板卡上启动运行。
+
+
+## 内核启动回调
+
+DragonOS对内核引导加载程序进行了抽象，体现为`BootCallbacks`这个trait。
+不同的引导加载程序，实现对应的callback，初始化内核bootParams或者是其他的一些数据结构。
+
+内核启动时，自动根据引导加载程序的类型，注册回调。并且在适当的时候，会调用这些回调函数。
 
 ## 参考资料
 

docs/kernel/boot/index.rst

@@ -8,4 +8,3 @@
    :caption: 目录
 
    bootloader
-   multiboot2

kernel/Cargo.toml

@@ -27,17 +27,17 @@ fatfs-secure = ["fatfs"]
 
 # 运行时依赖项
 [dependencies]
-acpi = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/acpi-rs.git", rev = "fb69243dcf" }
+acpi = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/acpi-rs.git", rev = "282df2af7b" }
 asm_macros = { path = "crates/asm_macros" }
 atomic_enum = "=0.2.0"
 bit_field = "=0.10"
 bitfield-struct = "=0.5.3"
 bitflags = "=1.3.2"
 bitmap = { path = "crates/bitmap" }
 driver_base_macros = { "path" = "crates/driver_base_macros" }
-# 一个no_std的hashmap、hashset
 elf = { version = "=0.7.2", default-features = false }
 fdt = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/fdt", rev = "9862813020" }
+# 一个no_std的hashmap、hashset
 hashbrown = "=0.13.2"
 ida = { path = "src/libs/ida" }
 intertrait = { path = "crates/intertrait" }
@@ -63,6 +63,7 @@ lru = "0.12.3"
 # target为x86_64时，使用下面的依赖
 [target.'cfg(target_arch = "x86_64")'.dependencies]
 mini-backtrace = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/mini-backtrace.git", rev = "e0b1d90940" }
+multiboot2 = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/multiboot2", rev = "05739aab40" }
 raw-cpuid = "11.0.1"
 x86 = "=0.52.0"
 x86_64 = "=0.14.10"

kernel/src/arch/riscv64/driver/sbi.rs

@@ -1,3 +1,5 @@
+use core::ptr::addr_of;
+
 /// 向控制台打印字符串。
 ///
 /// 该函数接受一个字节切片 `s` 作为输入，并迭代切片中的每个字节 `c`。
@@ -75,7 +77,7 @@ impl SbiDriver {
 
     /// 获取probe得到的SBI扩展信息。
     pub fn extensions() -> &'static SBIExtensions {
-        unsafe { &EXTENSIONS }
+        unsafe { addr_of!(EXTENSIONS).as_ref().unwrap() }
     }
 
     fn probe_extensions() -> SBIExtensions {

kernel/src/arch/riscv64/init/boot.rs

@@ -0,0 +1,15 @@
+use system_error::SystemError;
+
+use super::dragonstub::early_dragonstub_init;
+
+#[derive(Debug)]
+#[repr(u64)]
+pub(super) enum BootProtocol {
+    DragonStub = 1,
+}
+
+pub(super) fn early_boot_init(protocol: BootProtocol) -> Result<(), SystemError> {
+    match protocol {
+        BootProtocol::DragonStub => early_dragonstub_init(),
+    }
+}

kernel/src/arch/riscv64/init/dragonstub.rs

@@ -0,0 +1,41 @@
+use alloc::string::String;
+use system_error::SystemError;
+
+use crate::{
+    driver::video::fbdev::base::BootTimeScreenInfo,
+    init::boot::{register_boot_callbacks, BootCallbacks, BootloaderAcpiArg},
+};
+
+pub(super) fn early_dragonstub_init() -> Result<(), SystemError> {
+    register_boot_callbacks(&DragonStubCallBack);
+    Ok(())
+}
+
+struct DragonStubCallBack;
+
+impl BootCallbacks for DragonStubCallBack {
+    fn init_bootloader_name(&self) -> Result<Option<String>, SystemError> {
+        Ok(format!("DragonStub").into())
+    }
+
+    fn init_acpi_args(&self) -> Result<BootloaderAcpiArg, SystemError> {
+        Ok(BootloaderAcpiArg::NotProvided)
+    }
+
+    fn init_kernel_cmdline(&self) -> Result<(), SystemError> {
+        // parsed in `early_init_scan_chosen()`
+        Ok(())
+    }
+
+    fn early_init_framebuffer_info(
+        &self,
+        _scinfo: &mut BootTimeScreenInfo,
+    ) -> Result<(), SystemError> {
+        unimplemented!("dragonstub early_init_framebuffer_info")
+    }
+
+    fn early_init_memory_blocks(&self) -> Result<(), SystemError> {
+        // parsed in `early_init_scan_memory()` and uefi driver
+        Ok(())
+    }
+}

kernel/src/arch/riscv64/init/mod.rs

@@ -3,7 +3,11 @@ use log::{debug, info};
 use system_error::SystemError;
 
 use crate::{
-    arch::{driver::sbi::SbiDriver, mm::init::mm_early_init},
+    arch::{
+        driver::sbi::SbiDriver,
+        init::boot::{early_boot_init, BootProtocol},
+        mm::init::mm_early_init,
+    },
     driver::{firmware::efi::init::efi_init, open_firmware::fdt::open_firmware_fdt_driver},
     init::{boot_params, init::start_kernel},
     mm::{memblock::mem_block_manager, PhysAddr, VirtAddr},
@@ -13,6 +17,9 @@ use crate::{
 
 use super::{cpu::init_local_context, interrupt::entry::handle_exception};
 
+mod boot;
+mod dragonstub;
+
 #[derive(Debug)]
 pub struct ArchBootParams {
     /// 启动时的fdt物理地址
@@ -119,6 +126,7 @@ pub fn early_setup_arch() -> Result<(), SystemError> {
         "DragonOS kernel is running on hart {}, fdt address:{:?}",
         hartid, fdt_paddr
     );
+    early_boot_init(BootProtocol::DragonStub).expect("Failed to init boot protocol!");
     mm_early_init();
 
     print_node(fdt.find_node("/").unwrap(), 0);

kernel/src/arch/riscv64/rand.rs

@@ -1,3 +1,13 @@
 pub fn rand() -> usize {
-    unimplemented!("RiscV64 rand");
+    static mut SEED: u64 = 0xdead_beef_cafe_babe;
+    let mut buf = [0u8; size_of::<usize>()];
+    for x in buf.iter_mut() {
+        unsafe {
+            // from musl
+            SEED = SEED.wrapping_mul(0x5851_f42d_4c95_7f2d);
+            *x = (SEED >> 33) as u8;
+        }
+    }
+    let x: usize = unsafe { core::mem::transmute(buf) };
+    return x;
 }