Merge branch 'isr-refactor'

Author: LunarLambda

examples/template/src/main.c

@@ -1,9 +1,7 @@
-#include <seven/version.h>
 #include <seven/hw/video/prelude.h>
 #include <seven/hw/video/bg_bitmap.h>
 #include <seven/hw/video/color_constants.h>
 
-libsevenEmitVersionString();
 
 int main(void)
 {

examples/vsync/src/main.c

@@ -12,11 +12,12 @@ int main(void)
 {
     // Set up the necessary interrupt handling
     irqInitDefault();
-    irqEnableFull(IRQ_VBLANK);
+    irqEnable(IRQ_VBLANK);
     irqHandlerSet(IRQ_VBLANK, vblank_callback);
 
     // Clear the force-blank bit
     REG_DISPCNT = 0;
+    REG_DISPSTAT = LCD_VBLANK_IRQ_ENABLE;
 
     while (1)
     {

libseven/include/seven/attributes.h

@@ -8,33 +8,26 @@
 
 #include <seven/base.h>
 
-#define _LIBSEVEN_SECCOUNT      _LIBSEVEN_STR2(__COUNTER__)
+#define _LIBSEVEN_COUNTER _LIBSEVEN_STR2(__COUNTER__)
 
-#define PACKED                  __attribute__((__packed__))
-#define ALIGN(n)                __attribute__((__aligned__(n)))
-#define NORETURN                __attribute__((__noreturn__))
-#define NOINLINE                __attribute__((__noinline__))
-#define ARM_CODE                __attribute__((__target__("arm"))) NOINLINE
-#define THUMB_CODE              __attribute__((__target__("thumb"))) NOINLINE
+#define ALIGN(n)          __attribute__((__aligned__(n)))
+#define ARM_CODE          __attribute__((__target__("arm"))) NOINLINE
+#define NOINLINE          __attribute__((__noinline__))
+#define NORETURN          __attribute__((__noreturn__))
+#define PACKED            __attribute__((__packed__))
+#define SECTION(name)     __attribute__((__section__(name)))
+#define THUMB_CODE        __attribute__((__target__("thumb"))) NOINLINE
 
-#define SECTION(name)           __attribute__((__section__(name)))
+#define IWRAM_CODE        SECTION(".iwram.text." _LIBSEVEN_COUNTER) NOINLINE
+#define IWRAM_DATA        SECTION(".iwram.data." _LIBSEVEN_COUNTER)
 
-#define IWRAM_SECTION(suffix)   SECTION(".iwram" suffix)
-#define IWRAM_OVERLAY(number)   SECTION(".iwram" #number)
+#define EWRAM_CODE        SECTION(".ewram.text." _LIBSEVEN_COUNTER) NOINLINE
+#define EWRAM_DATA        SECTION(".ewram.data." _LIBSEVEN_COUNTER)
 
-#define IWRAM_CODE              IWRAM_SECTION(".text." _LIBSEVEN_SECCOUNT) NOINLINE
-#define IWRAM_DATA              IWRAM_SECTION(".data." _LIBSEVEN_SECCOUNT)
-
-#define EWRAM_SECTION(suffix)   SECTION(".ewram" suffix)
-#define EWRAM_OVERLAY(number)   SECTION(".ewram" #number)
-
-#define EWRAM_CODE              EWRAM_SECTION(".text." _LIBSEVEN_SECCOUNT) NOINLINE
-#define EWRAM_DATA              EWRAM_SECTION(".data." _LIBSEVEN_SECCOUNT)
-
-#ifndef _LIBSEVEN_NOCOMPATIBLE
-    #define IWRAM_BSS           SECTION(".bss." _LIBSEVEN_SECCOUNT)
-    #define EWRAM_BSS           SECTION(".sbss." _LIBSEVEN_SECCOUNT)
+#ifdef LIBSEVEN_COMPATIBLE
+    #define IWRAM_BSS     SECTION(".bss." _LIBSEVEN_COUNTER)
+    #define EWRAM_BSS     SECTION(".sbss." _LIBSEVEN_COUNTER)
 #else
-    #define IWRAM_BSS           SECTION(".iwram_bss." _LIBSEVEN_SECCOUNT)
-    #define EWRAM_BSS           SECTION(".ewram_bss." _LIBSEVEN_SECCOUNT)
-#endif /* !_LIBSEVEN_NOCOMPATIBLE */
+    #define IWRAM_BSS     SECTION(".iwram_bss." _LIBSEVEN_COUNTER)
+    #define EWRAM_BSS     SECTION(".ewram_bss." _LIBSEVEN_COUNTER)
+#endif /* LIBSEVEN_COMPATIBLE */

libseven/include/seven/base.h

@@ -21,12 +21,14 @@
 #define _LIBSEVEN_STR(s) #s
 #define _LIBSEVEN_STR2(s) _LIBSEVEN_STR(s)
 
+#define _LIBSEVEN_TARGET_ARM __attribute__((__target__("arm"), __noinline__))
+#define _LIBSEVEN_NOINLINE __attribute__((__noinline__))
 #define _LIBSEVEN_NORETURN __attribute__((__noreturn__))
-#define _LIBSEVEN_ALIGN4 __attribute__((__aligned__(4)))
+#define _LIBSEVEN_ALIGNED __attribute__((__aligned__(4)))
 
 #define LIBSEVEN_VERSION_MAJOR 0
-#define LIBSEVEN_VERSION_MINOR 17
-#define LIBSEVEN_VERSION_PATCH 2
+#define LIBSEVEN_VERSION_MINOR 18
+#define LIBSEVEN_VERSION_PATCH 0
 
 #define LIBSEVEN_VERSION \
     _LIBSEVEN_STR2(LIBSEVEN_VERSION_MAJOR) "." \

libseven/include/seven/hw/irq.h

@@ -10,10 +10,6 @@
 
 _LIBSEVEN_EXTERN_C
 
-// Attribute for compiling functions in a way that is suitable for ISRs.
-//
-#define ISR_FUNCTION    IWRAM_CODE ARM_CODE
-
 // Interrupt Enable
 //
 #define REG_IE          VOLADDR(0x04000200, uint16_t)
@@ -28,11 +24,14 @@ _LIBSEVEN_EXTERN_C
 
 // Interrupt Service Routine Function Pointer
 //
-#define MEM_ISR         MEMADDR(0x03FFFFFC, IsrFn*)
+#define MEM_ISR         VOLADDR(0x03FFFFFC, IsrFn*)
+
+// Interrupt Flags used by BIOS
+#define MEM_IFBIOS      VOLADDR(0x03FFFFF8, uint16_t)
 
 // IRQ bitflags
 //
-enum IRQ
+enum IRQFlag
 {
     IRQ_VBLANK          = BIT(0),
     IRQ_HBLANK          = BIT(1),
@@ -57,7 +56,7 @@ enum IRQGroup
     IRQS_BLANK          = IRQ_VBLANK  | IRQ_HBLANK,
     IRQS_TIMER          = IRQ_TIMER_0 | IRQ_TIMER_1 | IRQ_TIMER_2 | IRQ_TIMER_3,
     IRQS_DMA            = IRQ_DMA_0   | IRQ_DMA_1   | IRQ_DMA_2   | IRQ_DMA_3,
-    // IRQs in this group can wake up the GBA from a svcStop() call.
+    // IRQs in this group can wake up the GBA from biosStop().
     IRQS_EXTERNAL       = IRQ_SERIAL  | IRQ_KEYPAD  | IRQ_CARTRIDGE,
     IRQS_ALL            = BITS(14),
 };
@@ -101,17 +100,13 @@ extern void irqInit(IsrFn *isr);
 // Initialize interrupt handling using a handler system.
 //
 // Used with the irqHandler* functions.
+// Supports nesting by calling irqUnmask() inside a handler.
 extern void irqInitDefault(void);
 
-// Initialize interrupt handling using a single handler function.
+// Initialize interrupt handling using an optional, single handler function.
 //
-extern void irqInitSimple(IrqHandlerFn *fn);
-
-// Initialize interrupt handling using a stub handler
-// that only acknowledges the IRQs and returns.
-//
-// This is enough for the BIOS interrupt wait functions to work.
-extern void irqInitStub(void);
+// Does not support nesting by default.
+extern void irqInitMinimal(IrqHandlerFn *fn);
 
 // Set the handler associated with the specified irq.
 //
@@ -138,17 +133,16 @@ extern uint16_t irqEnable(uint16_t irqs);
 // Returns the old value of the IE register.
 extern uint16_t irqDisable(uint16_t irqs);
 
-// Enable the specified IRQs and IRQ enable bits in the respective IO registers.
-//
-// Returns the old value of the IE register.
-extern uint16_t irqEnableFull(uint16_t irqs);
+// Calls a function with IRQs disabled, passing data as an argument.
+extern void irqFree(void (*f)(void *), void *arg);
 
-// Disable the specified IRQs and IRQ enable bits in the respective IO registers.
-//
-// Returns the old value of the IE register.
-extern uint16_t irqDisableFull(uint16_t irqs);
+// Mask IRQs at the CPU level.
+extern void irqMask(void);
 
-// Calls a function with IRQs disabled, passing data as an argument.
-extern void irqFree(void (*f)(void*), void *arg);
+// Unmask IRQs at the CPU level. Used for enabling nested interrupts.
+extern void irqUnmask(void);
+
+// Returns whether IRQs are masked at the CPU level.
+extern bool irqMasked(void);
 
 _LIBSEVEN_EXTERN_C_END

libseven/include/seven/hw/video/types.h

@@ -23,14 +23,14 @@ struct Matrix
     int16_t vdx; // vertical shearing factor
     int16_t hdy; // horizontal shearing factor
     int16_t vdy; // vertical scaling factor
-} _LIBSEVEN_ALIGN4;
+} _LIBSEVEN_ALIGNED;
 
 struct Object
 {
     uint16_t attr0;
     uint16_t attr1;
     uint16_t attr2;
     uint16_t _reserved;
-} _LIBSEVEN_ALIGN4;
+} _LIBSEVEN_ALIGNED;
 
 _LIBSEVEN_EXTERN_C_END

libseven/include/seven/types.h

@@ -66,7 +66,7 @@ typedef uintptr_t       uptr;
 #define USIZE_BITS      (CHAR_BIT * sizeof(usize))
 #define UPTR_BITS       (CHAR_BIT * sizeof(uptr))
 
-#ifndef _LIBSEVEN_NOCOMPATIBLE
+#ifdef LIBSEVEN_COMPATIBLE
 
 typedef i8              s8;
 typedef i16             s16;
@@ -96,4 +96,4 @@ typedef iptr            sptr;
 #define SSIZE_BITS      ISIZE_BITS
 #define SPTR_BITS       IPTR_BITS
 
-#endif /* !_LIBSEVEN_NOCOMPATIBLE */
+#endif /* LIBSEVEN_COMPATIBLE */

libseven/include/seven/version.h

@@ -8,11 +8,18 @@
 #include <seven/hw/irq.h>
 
 extern IsrFn isrDefault;
-extern IsrFn isrSimple;
-extern IsrFn isrStub;
-
-extern IrqHandlerFn* ISR_SIMPLE_HANDLER;
-extern IrqHandlerFn* ISR_DEFAULT_HANDLERS[16];
+extern IsrFn isrMinimal;
+
+// Mark these as volatile because LTO cannot verify that isrDefault/isrMinimal
+// is called because it's invoked indirectly through the hardware.
+//
+// This means LTO will consider calls to irqSetHandler and similar to be dead
+// accesses, and remove them entirely
+//
+// For our purposes, writing these does produce a side effect, so volatile is
+// actually the semantically correct option here.
+extern IrqHandlerFn * volatile ISR_MINIMAL_HANDLER;
+extern IrqHandlerFn * volatile ISR_DEFAULT_HANDLERS[16];
 
 extern void irqInit(IsrFn *isr)
 {
@@ -23,7 +30,6 @@ extern void irqInit(IsrFn *isr)
     MEM_ISR = isr;
 
     REG_IME = 1;
-    return;
 }
 
 extern void irqInitDefault(void)
@@ -38,18 +44,13 @@ extern void irqInitDefault(void)
     irqInit(isrDefault);
 }
 
-extern void irqInitSimple(IrqHandlerFn *handler)
+extern void irqInitMinimal(IrqHandlerFn *handler)
 {
     REG_IME = 0;
 
-    ISR_SIMPLE_HANDLER = handler;
-
-    irqInit(isrSimple);
-}
+    ISR_MINIMAL_HANDLER = handler;
 
-extern void irqInitStub(void)
-{
-    irqInit(isrStub);
+    irqInit(isrMinimal);
 }
 
 extern bool irqHandlerSet(uint16_t irq, IrqHandlerFn *fn)
@@ -118,14 +119,49 @@ extern uint16_t irqDisable(uint16_t irqs)
     return old;
 }
 
-extern void irqFree(void (*f)(void*), void *arg)
+extern void irqFree(void (*f)(void *), void *arg)
 {
     uint32_t ime = REG_IME;
     REG_IME = 0;
 
     f(arg);
 
     REG_IME = ime;
+}
+
+_LIBSEVEN_TARGET_ARM extern void irqMask(void)
+{
+    __asm__ volatile
+    (
+        "mrs r0, cpsr\n"
+        "orr r0, r0, 0x80\n"
+        "msr cpsr_c, r0\n"
+        ::: "r0"
+    );
+}
+
+_LIBSEVEN_TARGET_ARM extern void irqUnmask(void)
+{
+    __asm__ volatile
+    (
+        "mrs r0, cpsr\n"
+        "bic r0, r0, 0x80\n"
+        "msr cpsr_c, r0\n"
+        ::: "r0"
+    );
+}
+
+_LIBSEVEN_TARGET_ARM extern bool irqMasked(void)
+{
+    bool masked;
+
+    __asm__ volatile
+    (
+        "mrs %0, cpsr\n"
+        "lsr %0, %0, 7\n"
+        "and %0, %0, 1\n"
+        : "=r"(masked)
+    );
 
-    return;
+    return masked;
 }