Extra Credit

Part 1. GUI

1. ModeX Screen Support (GUI/screen.c, GUI/gui_screen.c)

• Automatic double buffer management for image buffering without explicit operation

• Unified screen operation interface

2. Window Support (GUI/window.c, GUI/gui.c)

• Virtualization of the window. The user state needn't know any information about the size and position of the window, and from the user's view, each process seems to have the entire screen

• Multiple windows support (on the same screen). Supports displaying any number of windows simultaneously

• Management and display of multi-window overlapping relationships (multi-layer management)

• Support for screen pre-rendering to save computational resources (dynamically buffers the underlying window image)

• Window support for mouse-based movement, zooming, switching, full screen, minimizing

• Support mouse-based front-end scheduling. Window scheduling can cooperate with the scheduler for front-end process switching

• Provides a flexible system call interface for users to draw windows

3. GUI Terminal Support (GUI/gui_terminal.c)

• Through the unified terminal function predefined interface, we can quickly switch between text terminal and GUI terminal without modifying other code

• Each terminal has its own window, and like other types of window applications, terminal also supports the operations supported by the window, as well as mouse-based pre-stage scheduling

• GUI and text terminal share the same set of system call interfaces, easy to maintain and extend

4. Widget Support (GUI/gui_interaction.c)

• Provides a general interface to the widget

• Support automatic capture and processing of widget activities

• Support multi-level widget nesting

• System-level menus are implemented based on widgets (including the start menu, palette interface, color picker, right-click menu, etc.)

5. Dynamic Color Settings and Palette Settings (GUI/gui_color.c, GUI/gui_interaction.c)

• Support dynamic color palette change

• Support dynamic adjustment of system component colors

6. User interaction support (GUI/gui.c, GUI/gui_interaction.c)

• Support mouse-based graphical interaction, including movement, widget triggering, swiping, taskbar, etc.

Part 2. Memory Management

1. Overall Structure

• The system's memory management implements a three-level structure. The physical memory management is based on Buddy System to **reduce ** external fragmentation. The Slab Cache, an object-based allocation cache, is built on top of the Buddy System for fast allocation and release of objects of the same size. A kmalloc allocator is built on the Slab layer to allocate memory of arbitrary size.

2. Buddy system-based physical memory management (memoryalloc/buddy.c)

• Reduce external fragmentation by using the Buddy System for physical memory management. The Buddy System also implements a contiguous page allocator.

3. Slab Cache (memoryalloc/slab.c)

• Using Slab Cache for object management and creating a buffer pool for fixed-length sizes can greatly reduce the number of page mappings

4. kmalloc (memoryalloc/malloc.c)

• kmalloc allocator is created on Slab Cache for small and medium-sized objects

5. User malloc (memoryalloc/malloc.c)

• Build on the above three systems to implement user-state memory allocation

Part 3. File System

1. ATA Disk Driver (disk/ata.c)

• Support ATA disk block sequential read/write

• Support to obtain ATA information, including spatial information, etc.

2. ATA Disk-Based Permanent Read/Write File System (disk/disk_filesys.c, syscall.c, filesys.c)

• Multi-level directory support and support for using the parent directory identifier "..." in the path and the current directory identifier "."

• Dynamic inode, datablock allocation. Support for bitmap to provide fast finding of free blocks

• Support dynamic creation of files and directories

• Support file writing and dynamic expansion of data blocks

• Support superblock write-back to update file information

• Support for disk formatting

• Support Unified File Interface (VFS), coexisting and compatible with the original memory file system

• This file system is mounted in a directory of the original memory file system

Part 4. Signal

1. Support all Signal Functions Requested by MP3 Doc (signal.c)

• Support user-defined Signal behavior

• Support RTC to send ALARM signal at regular intervals

• Support keyboard to send INTERRUPT signal via Ctrl+C

2. Support User State Sending Signal to Other Processes(signal.c)

• Support this operation to facilitate communication between multi-threaded programs

Part 5. Multi-Thread Support

1. Multi-Thread Support (scheduling.c)

• Support user-state processes to create threads based on functions

• Threads inherit the address space of the process and have a separate user stack

• Support for running multi-threaded programs in user state (each process can create >= 1 thread)

• Support address space sharing and variable sharing

• Support user state process kill a thread

• Threads also support Signal. Customizable Signal behavior for thread communication and synchronization

2. Sleep Support (scheduling.c)

• Sleep and wake-up support, tell the scheduler to hibernate and wake up through flag bit setting

Part 6. Devices

1. Mouse (GUI/mouse.c)

• Virtualization. The mouse returns to the user the position inside the window. The movement of the window does not on the user state program

2. Sound (device/sound.c)

• Support for making individual note sounds

3. RTC (rtc.c)

• Random number generator