simple gui app can run now!

user/Cargo.toml

@@ -10,6 +10,7 @@ edition = "2018"
 buddy_system_allocator = "0.6"
 bitflags = "1.2.1"
 riscv = { git = "https://github.com/rcore-os/riscv", features = ["inline-asm"] }
+embedded-graphics = "0.7.1"
 
 [profile.release]
 debug = true

user/src/bin/gui_simple.rs

@@ -0,0 +1,35 @@
+#![no_std]
+#![no_main]
+
+use user_lib::{framebuffer, framebuffer_flush};
+
+#[macro_use]
+extern crate user_lib;
+
+// use embedded_graphics::pixelcolor::Rgb888;
+// use embedded_graphics::prelude::{Drawable, Point, RgbColor, Size};
+// use embedded_graphics::primitives::Primitive;
+// use embedded_graphics::primitives::{PrimitiveStyle, Rectangle};
+// use embedded_graphics::{
+//     draw_target::DrawTarget,
+//     prelude::{OriginDimensions},
+// };
+pub const VIRTGPU_XRES: usize = 1280;
+pub const VIRTGPU_YRES: usize = 800;
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let fb_ptr =framebuffer() as *mut u8;
+    println!("Hello world from user mode program! 0x{:X} , len {}", fb_ptr as usize, VIRTGPU_XRES*VIRTGPU_YRES*4);
+    let fb= unsafe {core::slice::from_raw_parts_mut(fb_ptr as *mut u8, VIRTGPU_XRES*VIRTGPU_YRES*4 as usize)};
+    for y in 0..800 {
+        for x in 0..1280 {
+            let idx = (y * 1280 + x) * 4;
+            fb[idx] = x as u8;
+            fb[idx + 1] = y as u8;
+            fb[idx + 2] = (x + y) as u8;
+        }
+    }
+    framebuffer_flush();
+    0
+}

user/src/lib.rs

@@ -198,6 +198,12 @@ pub fn condvar_signal(condvar_id: usize) {
 pub fn condvar_wait(condvar_id: usize, mutex_id: usize) {
     sys_condvar_wait(condvar_id, mutex_id);
 }
+pub fn framebuffer() -> isize {
+    sys_framebuffer()
+}
+pub fn framebuffer_flush() -> isize {
+    sys_framebuffer_flush()
+}
 
 #[macro_export]
 macro_rules! vstore {

user/src/syscall.rs

@@ -25,6 +25,8 @@ const SYSCALL_SEMAPHORE_DOWN: usize = 1022;
 const SYSCALL_CONDVAR_CREATE: usize = 1030;
 const SYSCALL_CONDVAR_SIGNAL: usize = 1031;
 const SYSCALL_CONDVAR_WAIT: usize = 1032;
+const SYSCALL_FRAMEBUFFER: usize = 2000;
+const SYSCALL_FRAMEBUFFER_FLUSH: usize = 2001;
 
 fn syscall(id: usize, args: [usize; 3]) -> isize {
     let mut ret: isize;
@@ -154,3 +156,12 @@ pub fn sys_condvar_signal(condvar_id: usize) -> isize {
 pub fn sys_condvar_wait(condvar_id: usize, mutex_id: usize) -> isize {
     syscall(SYSCALL_CONDVAR_WAIT, [condvar_id, mutex_id, 0])
 }
+
+
+pub fn sys_framebuffer() -> isize {
+    syscall(SYSCALL_FRAMEBUFFER, [0, 0, 0])
+}
+
+pub fn sys_framebuffer_flush() -> isize {
+    syscall(SYSCALL_FRAMEBUFFER_FLUSH, [0, 0, 0])
+}