Improve codestyle in asm_routines.s, remove unsafe save implementation in hyperspace-roll.

agb/src/asm_include.s

@@ -13,3 +13,19 @@
 .size \functionName,.-\functionName
 .endfunc
 .endm
+
+.macro agb_thumb_func functionName:req
+.section .iwram.\functionName, "ax", %progbits
+.thumb
+.align 2
+.global \functionName
+.type \functionName, %function
+.func \functionName
+\functionName:
+.endm
+
+.macro agb_thumb_end functionName:req
+.pool
+.size \functionName,.-\functionName
+.endfunc
+.endm

agb/src/save/asm_routines.s

@@ -1,89 +1,49 @@
+.include "src/asm_include.s"
+
 @
 @ char WramReadByte(const char* offset);
 @
 @ A routine that reads a byte from a given memory offset.
 @
-    .thumb
-    .global WramReadByte
-    .thumb_func
-    .align 2
-WramReadByte:
-    ldr r1, =WramReadByteInner
-    bx r1
-
-    .section .data
-
-    .thumb
-    .thumb_func
-    .align 2
-WramReadByteInner:
+agb_thumb_func agb_rs__WramReadByte
     ldrb r0, [r0]
     mov pc, lr
-
-    .section .text
+agb_thumb_end agb_rs__WramReadByte
 
 @
 @ bool WramVerifyBuf(const char* buf1, const char* buf2, int count);
 @
 @ A routine that compares two memory offsets.
 @
-    .thumb
-    .global WramVerifyBuf
-    .thumb_func
-    .align 2
-WramVerifyBuf:
+agb_thumb_func agb_rs__WramVerifyBuf
     push {r4-r5, lr}
     movs r5, r0     @ set up r5 to be r0, so we can use it immediately for the return result
     movs r0, #0     @ set up r0 so the default return result is false
-    ldr r4, =WramVerifyBufInner
-    bx r4           @ jump to the part in WRAM
 
-    .section .data
-
-    .thumb
-    .thumb_func
-    .align 2
-WramVerifyBufInner:
     @ At this point, buf1 is actually in r5, so r0 can be used as a status return
-    ldrb r3, [r5,r2]
+1:  ldrb r3, [r5,r2]
     ldrb r4, [r1,r2]
     cmp r3, r4
     bne 0f
     sub r2, #1
-    bpl WramVerifyBufInner
+    bpl 1b
 
     @ Returns from the function successfully
     movs r0, #1
 0:  @ Jumps to here return the function unsuccessfully, because r0 contains 0 at this point
     pop {r4-r5, pc}
+agb_thumb_end agb_rs__WramVerifyBuf
 
-    .section .text
 
 @
 @ void WramXferBuf(const char* source, char* dest, int count);
 @
 @ A routine that copies one buffer into another.
 @
-    .thumb
-    .global WramXferBuf
-    .thumb_func
-    .align 2
-WramXferBuf:
-    ldr r3, =WramXferBufInner
-    bx r3
-
-    .pool
-    .section .data
-
-    .thumb
-    .thumb_func
-    .align 2
-WramXferBufInner:
-    sub r2, #1
+agb_thumb_func agb_rs__WramXferBuf
+0:  sub r2, #1
     ldrb r3, [r0,r2]
     strb r3, [r1,r2]
-    bne WramXferBufInner
+    bne 0b
     mov pc, lr
-
-    .pool
-    .section .text
+agb_thumb_end agb_rs__WramXferBuf

agb/src/save/asm_utils.rs

@@ -3,9 +3,9 @@
 //! performed via code in WRAM and cannot be accessed by DMA.
 
 extern "C" {
-    fn WramXferBuf(src: *const u8, dst: *mut u8, count: usize);
-    fn WramReadByte(src: *const u8) -> u8;
-    fn WramVerifyBuf(buf1: *const u8, buf2: *const u8, count: usize) -> bool;
+    fn agb_rs__WramXferBuf(src: *const u8, dst: *mut u8, count: usize);
+    fn agb_rs__WramReadByte(src: *const u8) -> u8;
+    fn agb_rs__WramVerifyBuf(buf1: *const u8, buf2: *const u8, count: usize) -> bool;
 }
 
 /// Copies data from a given memory address into a buffer.
@@ -18,7 +18,7 @@ extern "C" {
 #[inline(always)]
 pub unsafe fn read_raw_buf(dst: &mut [u8], src: usize) {
     if dst.len() != 0 {
-        WramXferBuf(src as _, dst.as_mut_ptr(), dst.len());
+        agb_rs__WramXferBuf(src as _, dst.as_mut_ptr(), dst.len());
     }
 }
 
@@ -31,7 +31,7 @@ pub unsafe fn read_raw_buf(dst: &mut [u8], src: usize) {
 #[inline(always)]
 pub unsafe fn write_raw_buf(dst: usize, src: &[u8]) {
     if src.len() != 0 {
-        WramXferBuf(src.as_ptr(), dst as _, src.len());
+        agb_rs__WramXferBuf(src.as_ptr(), dst as _, src.len());
     }
 }
 
@@ -45,7 +45,7 @@ pub unsafe fn write_raw_buf(dst: usize, src: &[u8]) {
 #[inline(always)]
 pub unsafe fn verify_raw_buf(buf1: &[u8], buf2: usize) -> bool {
     if buf1.len() != 0 {
-        WramVerifyBuf(buf1.as_ptr(), buf2 as _, buf1.len() - 1)
+        agb_rs__WramVerifyBuf(buf1.as_ptr(), buf2 as _, buf1.len() - 1)
     } else {
         true
     }
@@ -59,5 +59,5 @@ pub unsafe fn verify_raw_buf(buf1: &[u8], buf2: usize) -> bool {
 /// This uses raw addresses into the memory space. Use with care.
 #[inline(always)]
 pub unsafe fn read_raw_byte(src: usize) -> u8 {
-    WramReadByte(src as _)
+    agb_rs__WramReadByte(src as _)
 }

agb/src/save/mod.rs

@@ -370,7 +370,7 @@ impl SaveManager {
     /// given save type.
     ///
     /// Only one `init_*` function may be called in the lifetime of the program.
-    pub fn init_sram() {
+    pub fn init_sram(&mut self) {
         marker::emit_sram_marker();
         set_save_implementation(&sram::BatteryBackedAccess);
     }
@@ -379,14 +379,15 @@ impl SaveManager {
     ///
     /// You must have initialized the save manager beforehand to use a specific
     /// type of media before calling this method.
-    pub fn access() -> Result<SaveData, Error> {
+    pub fn access(&mut self) -> Result<SaveData, Error> {
         SaveData::new(None)
     }
+
     /// Creates a new accessor to the save data that uses the given timer for timeouts.
     ///
     /// You must have initialized the save manager beforehand to use a specific
     /// type of media before calling this method.
-    pub fn access_with_timer(timer: Timer) -> Result<SaveData, Error> {
+    pub fn access_with_timer(&mut self, timer: Timer) -> Result<SaveData, Error> {
         SaveData::new(Some(timer))
     }
 }

examples/hyperspace-roll/src/main.rs

@@ -96,10 +96,10 @@ struct Agb<'a> {
 }
 
 fn main(mut gba: agb::Gba) -> ! {
-    save::init_save();
+    save::init_save(&mut gba).expect("Could not initialize save game");
 
     if save::load_high_score() > 1000 {
-        save::save_high_score(0);
+        save::save_high_score(&mut gba, 0).expect("Could not reset high score");
     }
 
     let gfx = gba.display.object.get();
@@ -207,7 +207,8 @@ fn main(mut gba: agb::Gba) -> ! {
                     agb.obj.commit();
                     agb.sfx.customise();
                     if save::load_high_score() < current_level {
-                        save::save_high_score(current_level);
+                        save::save_high_score(&mut gba, current_level)
+                            .expect("Could not save high score");
                     }
                     break;
                 }

examples/hyperspace-roll/src/save.rs

@@ -1,44 +1,42 @@
-use agb::interrupt::free;
-use bare_metal::Mutex;
-use core::cell::RefCell;
+use agb::Gba;
+use agb::save::Error;
+use agb::sync::Static;
 
-const RAM_ADDRESS: *mut u8 = 0x0E00_0000 as *mut u8;
-const HIGH_SCORE_ADDRESS_START: *mut u8 = RAM_ADDRESS.wrapping_offset(1);
+static HIGHSCORE: Static<u32> = Static::new(0);
 
-static HIGHSCORE: Mutex<RefCell<u32>> = Mutex::new(RefCell::new(0));
+pub fn init_save(gba: &mut Gba) -> Result<(), Error> {
+    gba.save.init_sram();
 
-pub fn init_save() {
-    if (unsafe { RAM_ADDRESS.read_volatile() } == !0) {
-        save_high_score(0);
-        unsafe { RAM_ADDRESS.write_volatile(0) };
-    }
+    let mut access = gba.save.access()?;
 
-    let mut a = [0; 4];
-    for (idx, a) in a.iter_mut().enumerate() {
-        *a = unsafe { HIGH_SCORE_ADDRESS_START.add(idx).read_volatile() };
-    }
+    let mut buffer = [0; 1];
+    access.read(0, &mut buffer)?;
 
-    let high_score = u32::from_le_bytes(a);
+    if buffer[0] != 0 {
+        access.prepare_write(0..1)?.write(0, &[0])?;
+        core::mem::drop(access);
+        save_high_score(gba, 0)?;
+    } else {
+        let mut buffer = [0; 4];
+        access.read(1, &mut buffer)?;
+        let high_score = u32::from_le_bytes(buffer);
 
-    free(|cs| {
         if high_score > 100 {
-            HIGHSCORE.borrow(cs).replace(0);
+            HIGHSCORE.write(0)
         } else {
-            HIGHSCORE.borrow(cs).replace(high_score);
+            HIGHSCORE.write(high_score)
         }
-    });
+    }
+
+    Ok(())
 }
 
 pub fn load_high_score() -> u32 {
-    free(|cs| *HIGHSCORE.borrow(cs).borrow())
+    HIGHSCORE.read()
 }
 
-pub fn save_high_score(score: u32) {
-    let a = score.to_le_bytes();
-
-    for (idx, &a) in a.iter().enumerate() {
-        unsafe { HIGH_SCORE_ADDRESS_START.add(idx).write_volatile(a) };
-    }
-
-    free(|cs| HIGHSCORE.borrow(cs).replace(score));
+pub fn save_high_score(gba: &mut Gba, score: u32) -> Result<(), Error> {
+    gba.save.access()?.prepare_write(1..5)?.write(1, &score.to_le_bytes())?;
+    HIGHSCORE.write(score);
+    Ok(())
 }