设备驱动模型：完善platform bus相关内容。并注册串口到sysfs (#403)

* 完成初始化platform bus
* 删除旧的sysfs
* 把uart驱动移动到tty/serial文件夹下
* 完成将串口挂载到sysfs
* 修复vfs系统调用未能follow symlink的问题
* 修复shell未能正确获取pwd的问题

kernel/src/arch/io.rs

@@ -0,0 +1,9 @@
+/// 每个架构都需要实现的IO接口
+pub trait PortIOArch {
+    unsafe fn in8(port: u16) -> u8;
+    unsafe fn in16(port: u16) -> u16;
+    unsafe fn in32(port: u16) -> u32;
+    unsafe fn out8(port: u16, data: u8);
+    unsafe fn out16(port: u16, data: u16);
+    unsafe fn out32(port: u16, data: u32);
+}

kernel/src/arch/mod.rs

@@ -7,6 +7,8 @@ use crate::{
     mm::PhysAddr,
 };
 
+pub mod io;
+
 /// TraitPciArch Pci架构相关函数，任何架构都应独立实现trait里的函数
 pub trait TraitPciArch {
     /// @brief 读取寄存器值，x86_64架构通过读取两个特定io端口实现

kernel/src/arch/x86_64/asm/mod.rs

@@ -1,2 +1,3 @@
 pub mod bitops;
 pub mod irqflags;
+pub mod pio;

kernel/src/arch/x86_64/asm/pio.rs

@@ -0,0 +1,35 @@
+use crate::arch::io::PortIOArch;
+
+pub struct X86_64PortIOArch;
+
+impl PortIOArch for X86_64PortIOArch {
+    #[inline(always)]
+    unsafe fn in8(port: u16) -> u8 {
+        x86::io::inb(port)
+    }
+
+    #[inline(always)]
+    unsafe fn in16(port: u16) -> u16 {
+        x86::io::inw(port)
+    }
+
+    #[inline(always)]
+    unsafe fn in32(port: u16) -> u32 {
+        x86::io::inl(port)
+    }
+
+    #[inline(always)]
+    unsafe fn out8(port: u16, data: u8) {
+        x86::io::outb(port, data)
+    }
+
+    #[inline(always)]
+    unsafe fn out16(port: u16, data: u16) {
+        x86::io::outw(port, data)
+    }
+
+    #[inline(always)]
+    unsafe fn out32(port: u16, data: u32) {
+        x86::io::outl(port, data)
+    }
+}

kernel/src/arch/x86_64/mm/mod.rs

@@ -5,7 +5,7 @@ use hashbrown::HashSet;
 use x86::time::rdtsc;
 use x86_64::registers::model_specific::EferFlags;
 
-use crate::driver::uart::uart_device::c_uart_send_str;
+use crate::driver::tty::serial::serial8250::send_to_default_serial8250_port;
 use crate::include::bindings::bindings::{
     multiboot2_get_memory, multiboot2_iter, multiboot_mmap_entry_t,
 };
@@ -148,7 +148,7 @@ impl MemoryManagementArch for X86_64MMArch {
         // 初始化物理内存区域(从multiboot2中获取)
         let areas_count =
             Self::init_memory_area_from_multiboot2().expect("init memory area failed");
-        c_uart_send_str(0x3f8, "x86 64 init end\n\0".as_ptr());
+        send_to_default_serial8250_port("x86 64 init end\n\0".as_bytes());
 
         return &PHYS_MEMORY_AREAS[0..areas_count];
     }
@@ -229,7 +229,7 @@ impl X86_64MMArch {
     unsafe fn init_memory_area_from_multiboot2() -> Result<usize, SystemError> {
         // 这个数组用来存放内存区域的信息（从C获取）
         let mut mb2_mem_info: [multiboot_mmap_entry_t; 512] = mem::zeroed();
-        c_uart_send_str(0x3f8, "init_memory_area_from_multiboot2 begin\n\0".as_ptr());
+        send_to_default_serial8250_port("init_memory_area_from_multiboot2 begin\n\0".as_bytes());
 
         let mut mb2_count: u32 = 0;
         multiboot2_iter(
@@ -237,7 +237,7 @@ impl X86_64MMArch {
             &mut mb2_mem_info as *mut [multiboot_mmap_entry_t; 512] as usize as *mut c_void,
             &mut mb2_count,
         );
-        c_uart_send_str(0x3f8, "init_memory_area_from_multiboot2 2\n\0".as_ptr());
+        send_to_default_serial8250_port("init_memory_area_from_multiboot2 2\n\0".as_bytes());
 
         let mb2_count = mb2_count as usize;
         let mut areas_count = 0usize;
@@ -255,7 +255,7 @@ impl X86_64MMArch {
                 areas_count += 1;
             }
         }
-        c_uart_send_str(0x3f8, "init_memory_area_from_multiboot2 end\n\0".as_ptr());
+        send_to_default_serial8250_port("init_memory_area_from_multiboot2 end\n\0".as_bytes());
         kinfo!("Total memory size: {} MB, total areas from multiboot2: {mb2_count}, valid areas: {areas_count}", total_mem_size / 1024 / 1024);
 
         return Ok(areas_count);
@@ -291,7 +291,7 @@ impl VirtAddr {
 
 /// @brief 初始化内存管理模块
 pub fn mm_init() {
-    c_uart_send_str(0x3f8, "mm_init\n\0".as_ptr());
+    send_to_default_serial8250_port("mm_init\n\0".as_bytes());
     PrintkWriter
         .write_fmt(format_args!("mm_init() called\n"))
         .unwrap();
@@ -301,7 +301,7 @@ pub fn mm_init() {
         .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
         .is_err()
     {
-        c_uart_send_str(0x3f8, "mm_init err\n\0".as_ptr());
+        send_to_default_serial8250_port("mm_init err\n\0".as_bytes());
         panic!("mm_init() can only be called once");
     }
 

kernel/src/arch/x86_64/mod.rs

@@ -20,3 +20,5 @@ pub use self::pci::pci::X86_64PciArch as PciArch;
 pub use self::mm::X86_64MMArch as MMArch;
 
 pub use interrupt::X86_64InterruptArch as CurrentIrqArch;
+
+pub use crate::arch::asm::pio::X86_64PortIOArch as CurrentPortIOArch;