test/Makefile

@@ -6,8 +6,8 @@ build:
 	cargo build --release
 
 extract: build
-	riscv32-elf-objcopy -O binary --only-section=.text "target/riscv32i-unknown-none-elf/release/${NAME}" /tmp/text.bin
+	riscv32-elf-objcopy -O binary --only-section=.text "target/riscv32i-unknown-none-elf/release/${NAME}" ~/text.bin
-	riscv32-elf-objcopy -O binary --only-section=.rodata "target/riscv32i-unknown-none-elf/release/${NAME}" /tmp/rodata.bin
+	riscv32-elf-objcopy -O binary --only-section=.rodata "target/riscv32i-unknown-none-elf/release/${NAME}" ~/rodata.bin
 
 size: extract
 	cargo size --release -- -A

test/src/main.rs

@@ -14,27 +14,20 @@ fn panic_handler(_info: &PanicInfo) -> ! {
 
 const OUTPUT: *mut u32 = 0x2000_0000 as *mut u32;
 const BTNS: *mut u8 = 0x2000_0008 as *mut u8;
-const TEXT: *mut u32 = 0x2000_000C as *mut u32;
 const SCREEN: *mut u32 = 0x2000_0080 as *mut u32;
 
-const HELLO_WORLD: &[u8; 13] = b" Hello world!";
-
 #[entry]
 fn main() -> ! {
-    unsafe {
+    loop {
-        SCREEN.write_volatile(0b101);
-    }
-    for i in 0..31 {
         unsafe {
-            let mut x = SCREEN.offset(i).read_volatile();
+            SCREEN.write_volatile(0b101);
-            x <<= 1;
-            SCREEN.offset(i + 1).write_volatile(x);
         }
-    }
+        for i in 0..31 {
-    for ch in HELLO_WORLD {
+            unsafe {
-        unsafe {
+                let mut x = SCREEN.offset(i).read_volatile();
-            TEXT.write_volatile(*ch as u32);
+                x <<= 1;
+                SCREEN.offset(i+1).write_volatile(x);
+            }
         }
     }
-    loop {}
 }