New Error Handler with backtrace and symbol support (#377)

* New error handler from MD Debugger project with backtrace and source code symbols
  The original SGDK's error handler is available via LEGACY_ERROR_HANDLER option.
* Makefile.gen: Remove redundant character in `convsym` format string
* Add ConvSym 2.12 source code
* Split error handler from `sega.s` to `error_a.s`

Author: vladikcomper

bin/convsym.exe

@@ -19,6 +19,7 @@ ifeq ($(OS),Windows_NT)
 	LD:= $(BIN)/ld
 	NM:= $(BIN)/nm
 	OBJCPY := $(BIN)/objcopy
+	CONVSYM := $(BIN)/convsym
 	ASMZ80 := $(BIN)/sjasm
 	MACCER := $(BIN)/mac68k
 	BINTOS := $(BIN)/bintos
@@ -37,6 +38,7 @@ else
 	LD := $(PREFIX)ld
 	NM := $(PREFIX)nm
 	OBJCPY := $(PREFIX)objcopy
+	CONVSYM := convsym
 	ASMZ80 := sjasm
 	MACCER := mac68k
 	BINTOS := bintos

common.mk

@@ -81,6 +81,16 @@
  */
 #define LEGACY_SPRITE_ENGINE    0
 
+/**
+ * \brief
+ *      Set it to 1 to use the original SGDK's error handling screen and vectors.<br>
+ *      Otherwise error handler from the MD Debugger project is used, which supports source code symbols with "debug" build proifle and backtrace.<br>
+ *
+ *      The new error handler, however, completely takes over exception vectors and doesn't allow to set your own callbacks for errors (e.g. addressErrorCB).<br>
+ *      If you rely on callbacks to override error handling behavior, consider using legacy system instead.
+ */
+#define LEGACY_ERROR_HANDLER    0
+
 /**
  *  \brief
  *      Set it to 1 to enable automatic bank switch using official SEGA mapper for ROM > 4MB.

inc/config.h

@@ -93,7 +93,7 @@ typedef enum
     ON_VBLANK_START     /** Start VBlank process on VBlank *start* period, means that we wait the next *start* of VBlank period if we missed it */
 } VBlankProcessTime;
 
-
+#if LEGACY_ERROR_HANDLER
 /**
  *  \brief
  *      Bus error interrupt callback.
@@ -164,6 +164,8 @@ extern VoidCallback *line1x1xCB;
  * You can modify it to use your own callback (for debug purpose).
  */
 extern VoidCallback *errorExceptionCB;
+#endif
+
 /**
  *  \brief
  *      Level interrupt callback.

inc/sys.h

@@ -81,11 +81,12 @@ release: $(OUT)/rom.bin $(OUT)/symbol.txt
 #release: $(info $$var is [${SRC_C}])
 
 debug: FLAGS= $(DEFAULT_FLAGS) -O1 -DDEBUG=1
-debug: CFLAGS= $(FLAGS) -ggdb
+debug: CFLAGS= $(FLAGS) -ggdb -g
 debug: AFLAGS= $(FLAGS)
 debug: LIBMD= $(LIB)/libmd_debug.a
 debug: $(OUT)/rom.bin $(OUT)/rom.out $(OUT)/symbol.txt
-.PHONY: debug
+debug: injectSymbolsInROM
+.PHONY: debug injectSymbolsInROM
 
 asm: FLAGS= $(DEFAULT_FLAGS) -O3 -fuse-linker-plugin -fno-web -fno-gcse -fomit-frame-pointer -S
 asm: CFLAGS= $(FLAGS)
@@ -159,12 +160,15 @@ cleanAsm: cleanasm
 .PHONY: cleanRelease cleanDebug cleanAsm
 
 
-$(OUT)/rom.bin: $(OUT)/rom.out
+injectSymbolsInROM:	$(OUT)/rom.bin $(OUT)/rom.out $(OUT)/symbol.txt
+	$(CONVSYM) $(OUT)/symbol.txt $(OUT)/rom.bin -in txt -inopt "/fmt='%X %*[TtBbCcDd] %511s' /offsetFirst+" -range 0 FFFFFF -a -ref @MDDBG__SymbolDataPtr
+
+$(OUT)/rom.bin: $(OUT)/rom.out $(OUT)/symbol.txt
 	$(OBJCPY) -O binary $(OUT)/rom.out $(OUT)/rom.bin
 	$(SIZEBND) $(OUT)/rom.bin -sizealign 131072 -checksum
 
 $(OUT)/symbol.txt: $(OUT)/rom.out
-	$(NM) $(LTO_PLUGIN) -n $(OUT)/rom.out > $(OUT)/symbol.txt
+	$(NM) $(LTO_PLUGIN) -nl $(OUT)/rom.out > $(OUT)/symbol.txt
 
 $(OUT)/rom.out: $(OUT)/sega.o $(OUT)/cmd_ $(LIBMD)
 	$(MKDIR) -p $(dir $@)

lib/libmd.a

@@ -52,175 +52,46 @@ rom_header:
         .incbin "out/rom_head.bin", 0, 0x100
 
 _Entry_Point:
+* disable interrupts
         move    #0x2700,%sr
+
+* Configure a USER_STACK_LENGTH bytes user stack at bottom, and system stack on top of it
+        move    %sp, %usp
+        sub     #USER_STACK_LENGTH, %sp
+
+* Halt Z80 (need to be done as soon as possible on reset)
+        move.l  #0xA11100,%a0       /* Z80_HALT_PORT */
+        move.w  #0x0100,%d0
+        move.w  %d0,(%a0)           /* HALT Z80 */
+        move.w  %d0,0x0100(%a0)     /* END RESET Z80 */
+
         tst.l   0xa10008
-        bne.s   SkipJoyDetect
+        bne.s   SkipInit
 
         tst.w   0xa1000c
+        bne.s   SkipInit
 
-SkipJoyDetect:
-        bne.s   SkipSetup
-
-        lea     Table,%a5
-        movem.w (%a5)+,%d5-%d7
-        movem.l (%a5)+,%a0-%a4
 * Check Version Number
-        move.b  -0x10ff(%a1),%d0
+        move.b  -0x10ff(%a0),%d0
         andi.b  #0x0f,%d0
-        beq.s   WrongVersion
+        beq.s   NoTMSS
 
 * Sega Security Code (SEGA)
-        move.l  #0x53454741,0x2f00(%a1)
-WrongVersion:
-* Read from the control port to cancel any pending read/write command
-        move.w  (%a4),%d0
-
-* Configure a USER_STACK_LENGTH bytes user stack at bottom, and system stack on top of it
-        move    %sp, %usp
-        sub     #USER_STACK_LENGTH, %sp
-
-        move.w  %d7,(%a1)
-        move.w  %d7,(%a2)
-
-* Jump to initialisation process now...
+        move.l  #0x53454741,0x2f00(%a0)
 
+NoTMSS:
         jmp     _start_entry
 
-SkipSetup:
+SkipInit:
         jmp     _reset_entry
 
 
-Table:
-        dc.w    0x8000,0x3fff,0x0100
-        dc.l    0xA00000,0xA11100,0xA11200,0xC00000,0xC00004
-
-
 *------------------------------------------------
 *
 *       interrupt functions
 *
 *------------------------------------------------
 
-registersDump:
-        move.l %d0,registerState+0
-        move.l %d1,registerState+4
-        move.l %d2,registerState+8
-        move.l %d3,registerState+12
-        move.l %d4,registerState+16
-        move.l %d5,registerState+20
-        move.l %d6,registerState+24
-        move.l %d7,registerState+28
-        move.l %a0,registerState+32
-        move.l %a1,registerState+36
-        move.l %a2,registerState+40
-        move.l %a3,registerState+44
-        move.l %a4,registerState+48
-        move.l %a5,registerState+52
-        move.l %a6,registerState+56
-        move.l %a7,registerState+60
-        rts
-
-busAddressErrorDump:
-        move.w 4(%sp),ext1State
-        move.l 6(%sp),addrState
-        move.w 10(%sp),ext2State
-        move.w 12(%sp),srState
-        move.l 14(%sp),pcState
-        jmp registersDump
-
-exception4WDump:
-        move.w 4(%sp),srState
-        move.l 6(%sp),pcState
-        move.w 10(%sp),ext1State
-        jmp registersDump
-
-exceptionDump:
-        move.w 4(%sp),srState
-        move.l 6(%sp),pcState
-        jmp registersDump
-
-
-_Bus_Error:
-        jsr busAddressErrorDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  busErrorCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Address_Error:
-        jsr busAddressErrorDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  addressErrorCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Illegal_Instruction:
-        jsr exception4WDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  illegalInstCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Zero_Divide:
-        jsr exceptionDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  zeroDivideCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Chk_Instruction:
-        jsr exception4WDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  chkInstCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Trapv_Instruction:
-        jsr exception4WDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  trapvInstCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Privilege_Violation:
-        jsr exceptionDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  privilegeViolationCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Trace:
-        jsr exceptionDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  traceCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Line_1010_Emulation:
-_Line_1111_Emulation:
-        jsr exceptionDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  line1x1xCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
-_Error_Exception:
-        jsr exceptionDump
-        movem.l %d0-%d1/%a0-%a1,-(%sp)
-        move.l  errorExceptionCB, %a0
-        jsr    (%a0)
-        movem.l (%sp)+,%d0-%d1/%a0-%a1
-        rte
-
 _INT:
         movem.l %d0-%d1/%a0-%a1,-(%sp)
         move.l  intCB, %a0