[feat] 串口hex输出可选择是否补0

Makefile

@@ -135,7 +135,7 @@ disk: vdir
 
 run: disk
 	@echo "Launching QEMU"
-	@qemu-system-x86_64 -bios /usr/share/ovmf/OVMF.fd -net none -drive file=build/disk.img,index=0,format=raw -serial file:serial.log -s -S
+	@qemu-system-x86_64 -bios /usr/share/ovmf/OVMF.fd -net none -drive file=build/disk.img,index=0,format=raw -serial stdio -serial file:serial.log -s -S
 
 clean:
 	@echo "Cleaning old files"

include/serial.h

@@ -13,5 +13,5 @@ extern serial_context g_serial;
 void serial_init(EFI_SERIAL_IO_PROTOCOL *SerialIo); // 初始化串行驱动
 void serial_write(String str);                      // 往串行写string
 void serial_write_char(char c);                     // 往串行写char（不推荐使用）
-void serial_write_hex(UINTN val);                   // 往串行写十六进制数字
+void serial_write_hex(UINTN val, bool fill = true);  // 往串行写十六进制数字（fill=false 不补前导0）
 char serial_read_char();                            // 读串行

kernel/serial.cpp

@@ -32,15 +32,31 @@ void serial_write(String str) {
     }
 }
 
-void serial_write_hex(UINTN val) {
+void serial_write_hex(UINTN val, bool fill) {
     char buf[19];
-    buf[0] = '0'; buf[1] = 'x';
-    for (SSINT32 i = 17; i >= 2; i--) {
-        UINTN digit = val & 0xF;
-        buf[i] = digit < 10 ? '0' + digit : 'A' + digit - 10;
-        val >>= 4;
+    buf[0] = '0';
+    buf[1] = 'x';
+    SSINT32 pos = 2;
+    if (val == 0) {
+        buf[pos++] = '0';
+    } else {
+        char tmp[17];
+        SSINT32 len = 0;
+        while (val) {
+            UINTN digit = val & 0xF;
+            tmp[len++] = digit < 10 ? '0' + digit : 'A' + digit - 10;
+            val >>= 4;
+        }
+        if (fill) {
+            while (len < 16) {
+                buf[pos++] = '0';
+            }
+        }
+        for (SSINT32 i = len - 1; i >= 0; i--) {
+            buf[pos++] = tmp[i];
+        }
     }
-    buf[18] = '\0';
+    buf[pos] = '\0';
     serial_write(buf);
 }