🆕 uart驱动

.gitignore

@@ -6,3 +6,4 @@ kernel/kernel
 
 *.o
 *.s
+serial_opt.txt

kernel/Makefile

@@ -125,6 +125,11 @@ HPET.o: driver/timers/HPET/HPET.c
 timer.o: driver/timers/timer.c
 	gcc $(CFLAGS) -c driver/timers/timer.c -o driver/timers/timer.o
 
+OBJ_LIST += uart.o
+LD_LIST += driver/uart/uart.o
+uart.o: driver/uart/uart.c
+	gcc $(CFLAGS) -c driver/uart/uart.c -o driver/uart/uart.o
+
 
 
 all: kernel

kernel/common/glib.h

@@ -17,6 +17,7 @@
                                        : "memory") //关闭外部中断
 #define nop() __asm__ __volatile__("nop\n\t")
 #define hlt() __asm__ __volatile__("hlt\n\t")
+#define pause() asm volatile ("pause\n\t"); // 处理器等待一段时间
 
 //内存屏障
 #define io_mfence() __asm__ __volatile__("mfence\n\t" :: \

kernel/common/printk.c

@@ -7,6 +7,8 @@
 #include "../mm/mm.h"
 #include "../process/spinlock.h"
 
+#include <driver/uart/uart.h>
+
 //#include "linkage.h"
 
 struct screen_info pos;
@@ -110,13 +112,16 @@ void auto_newline()
      * @brief 超过每行最大字符数，自动换行
      *
      */
+     
     if (pos.x > pos.max_x)
     {
+        uart_send(COM1, '\n'); 
         pos.x = 0;
         ++pos.y;
     }
     if (pos.y > pos.max_y)
     {
+        uart_send(COM1, '\n');
         pos.y = pos.max_y;
         int lines_to_scroll = 1;
         scroll(true, lines_to_scroll * pos.char_size_y, false);
@@ -625,6 +630,8 @@ static void putchar(uint *fb, int Xsize, int x, int y, unsigned int FRcolor, uns
      * @param BKcolor 背景颜色
      * @param font 字符的bitmap
      */
+    // 输出到串口
+    uart_send(COM1, font);
 
     unsigned char *font_ptr = font_ascii[font];
     unsigned int *addr;

kernel/driver/uart/uart.c

@@ -0,0 +1,88 @@
+#include "uart.h"
+#include <common/kprint.h>
+
+#define UART_MAX_BITS_RATE 115200
+
+/**
+ * @brief 当前是否有数据到达
+ *
+ */
+#define serial_received(p) ((io_in8(p + 5) & 1))
+
+/**
+ * @brief 当前是否有数据正等待发送
+ *
+ */
+#define is_transmit_empty(p) ((io_in8(p + 5) & 0x20))
+
+/**
+ * @brief 初始化com口
+ *
+ * @param port com口的端口号
+ * @param bits_rate 通信的比特率
+ */
+int uart_init(uint32_t port, uint32_t bits_rate)
+{
+    // 错误的比特率
+    if (bits_rate > UART_MAX_BITS_RATE || UART_MAX_BITS_RATE % bits_rate != 0)
+        return E_UART_BITS_RATE_ERROR;
+
+    io_out8(port + 1, 0x00); // Disable all interrupts
+    io_out8(port + 3, 0x80); // Enable DLAB (set baud rate divisor)
+
+    uint16_t divisor = E_UART_BITS_RATE_ERROR / bits_rate;
+    io_out8(port + 0, divisor & 0xff);        // Set divisor  (lo byte)
+    io_out8(port + 1, (divisor >> 8) & 0xff); //                  (hi byte)
+    io_out8(port + 3, 0x03);                  // 8 bits, no parity, one stop bit
+    io_out8(port + 2, 0xC7);                  // Enable FIFO, clear them, with 14-byte threshold
+    io_out8(port + 4, 0x0B);                  // IRQs enabled, RTS/DSR set
+    io_out8(port + 4, 0x1E);                  // Set in loopback mode, test the serial chip
+    io_out8(port + 0, 0xAE);                  // Test serial chip (send byte 0xAE and check if serial returns same byte)
+
+    // Check if serial is faulty (i.e: not same byte as sent)
+    if (io_in8(port + 0) != 0xAE)
+    {
+        return E_UART_SERIAL_FAULT;
+    }
+
+    // If serial is not faulty set it in normal operation mode
+    // (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
+    io_out8(port + 4, 0x0F);
+    return UART_SUCCESS;
+
+    /*
+            Notice that the initialization code above writes to [PORT + 1]
+        twice with different values. This is once to write to the Divisor
+        register along with [PORT + 0] and once to write to the Interrupt
+        register as detailed in the previous section.
+            The second write to the Line Control register [PORT + 3]
+        clears the DLAB again as well as setting various other bits.
+    */
+}
+
+/**
+ * @brief 发送数据
+ *
+ * @param port 端口号
+ * @param c 要发送的数据
+ */
+void uart_send(uint32_t port, char c)
+{
+    while (is_transmit_empty(port) == 0)
+        pause();
+    io_out8(port, c);
+}
+
+/**
+ * @brief 从uart接收数据
+ *
+ * @param port 端口号
+ * @return uchar 接收到的数据
+ */
+uchar uart_read(uint32_t port)
+{
+    while (serial_received(port) == 0)
+        pause();
+    
+    return io_in8(port);
+}

kernel/driver/uart/uart.h

@@ -0,0 +1,64 @@
+/**
+ * @file uart.h
+ * @author longjin (longjin@RinGoTek.cn)
+ * @brief uart驱动程序 RS-232驱动
+ * @version 0.1
+ * @date 2022-04-15
+ * 
+ * @copyright Copyright (c) 2022
+ * 
+ */
+#pragma once
+
+#include <common/glib.h>
+
+#define UART_SUCCESS 0
+#define E_UART_BITS_RATE_ERROR 1
+#define E_UART_SERIAL_FAULT 2
+enum uart_port_io_addr
+{
+    COM1 = 0x3f8,
+    COM2 = 0x2f8,
+    COM3 = 0x3e8,
+    COM4 = 0x2e8,
+    COM5 = 0x5f8,
+    COM6 = 0x4f8,
+    COM7 = 0x5e8,
+    COM8 = 0x4E8,
+};
+
+enum uart_register_offset
+{
+    REG_DATA = 0,
+    REG_INTERRUPT_ENABLE = 1,
+    REG_II_FIFO = 2,    // 	Interrupt Identification and FIFO control registers
+    REG_LINE_CONTROL = 3,
+    REG_MODEM_CONTROL = 4,
+    REG_LINE_STATUS = 5,
+    REG_MODEM_STATUE = 6,
+    REG_SCRATCH = 7
+};
+
+/**
+ * @brief 初始化com口
+ * 
+ * @param port com口的端口号
+ * @param bits_rate 通信的比特率
+ */
+int uart_init(uint32_t port, uint32_t bits_rate);
+
+/**
+ * @brief 发送数据
+ * 
+ * @param port 端口号
+ * @param c 要发送的数据
+ */
+void uart_send(uint32_t port, char c);
+
+/**
+ * @brief 从uart接收数据
+ * 
+ * @param port 端口号
+ * @return uchar 接收到的数据
+ */
+uchar uart_read(uint32_t port);

kernel/main.c

@@ -27,6 +27,7 @@
 #include <driver/timers/rtc/rtc.h>
 #include <driver/timers/HPET/HPET.h>
 #include <driver/timers/timer.h>
+#include <driver/uart/uart.h>
 
 unsigned int *FR_address = (unsigned int *)0xb8000; //帧缓存区的地址
 ul bsp_idt_size, bsp_gdt_size;
@@ -83,6 +84,7 @@ void system_initialize()
 
     // 初始化printk
     printk_init(8, 16);
+    uart_init(COM1, 115200);
     kinfo("Kernel Starting...");
     // 重新加载gdt和idt
 
@@ -100,7 +102,6 @@ void system_initialize()
     kdebug("cpu_core_info[0].tss_vaddr=%#018lx", cpu_core_info[0].tss_vaddr);
     kdebug("cpu_core_info[0].stack_start%#018lx", cpu_core_info[0].stack_start);
 
-    
     // 初始化中断描述符表
     sys_vector_init();
 
@@ -145,14 +146,10 @@ void system_initialize()
     // test_slab();
     // test_mm();
 
-
     // process_init();
     current_pcb->cpu_id = 0;
     current_pcb->preempt_count = 0;
     HPET_init();
-
-
-    
 }
 
 //操作系统内核从这里开始执行
@@ -177,7 +174,6 @@ void Start_Kernel(void)
     multiboot2_magic = (uint)mb2_magic;
     multiboot2_boot_info_addr = mb2_info + PAGE_OFFSET;
 
-    
     system_initialize();
 
     /*

run.sh

@@ -93,7 +93,7 @@ if [ $flag_can_run -eq 1 ]; then
         bochs -q -f ${bochsrc} -rc ./tools/bochsinit
     else
         qemu-system-x86_64 -cdrom ${iso} -m 512M -smp 2,cores=2,threads=1,sockets=1 \
-        -monitor stdio -d cpu_reset,guest_errors,trace:check_exception,exec,cpu,out_asm,in_asm -s -S -cpu IvyBridge --enable-kvm -rtc clock=host,base=localtime \
+        -monitor stdio -d cpu_reset,guest_errors,trace:check_exception,exec,cpu,out_asm,in_asm -s -S -cpu IvyBridge --enable-kvm -rtc clock=host,base=localtime -serial file:serial_opt.txt \
         -drive id=disk,file=bin/disk.img,if=none \
         -device ahci,id=ahci \
         -device ide-hd,drive=disk,bus=ahci.0    \