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| /****************************************************************************** |
| FILE : start08.c |
| PURPOSE : 68HC08 standard startup code |
| LANGUAGE : ANSI-C / INLINE ASSEMBLER |
| ---------------------------------------------------------------------------- |
| HISTORY |
| 22 oct 93 Created. |
| 04/17/97 Also C++ constructors called in Init(). |
| ******************************************************************************/ |
| |
| /**********************************************************************/ |
| /* NOTE: */ |
| /* This version of the startup code does assumes that main */ |
| /* does never return (saving the 2 byte return address of _Startup on */ |
| /* the stack). */ |
| /**********************************************************************/ |
| |
| #define __NO_FLAGS_OFFSET /* we do not need the flags field in the startup data descriptor */ |
| #define __NO_MAIN_OFFSET /* we do not need the main field in the startup data descriptor */ |
| |
| #include <start08.h> |
| |
| #ifdef __cplusplus |
| #define __EXTERN_C extern "C" |
| #else |
| #define __EXTERN_C |
| #endif |
| |
| |
| /**********************************************************************/ |
| /* __ONLY_INIT_SP define: */ |
| /* This define selects an shorter version of the startup code */ |
| /* which only loads the stack pointer and directly afterwards calls */ |
| /* main. This version does however NOT initialized global variables */ |
| /* (So this version is not ANSI compliant!) */ |
| /**********************************************************************/ |
| |
| #ifndef __ONLY_INIT_SP |
| |
| #pragma DATA_SEG FAR _STARTUP |
| struct _tagStartup _startupData; /* read-only: |
| _startupData is allocated in ROM and |
| initialized by the linker */ |
| |
| #pragma MESSAGE DISABLE C20001 /* Warning C20001: Different value of stackpointer depending on control-flow */ |
| /* the function _COPY_L releases some bytes from the stack internally */ |
| |
| #ifdef __OPTIMIZE_FOR_SIZE__ |
| #pragma NO_ENTRY |
| #pragma NO_EXIT |
| #pragma NO_FRAME |
| /*lint -esym(528, loadByte) inhibit warning about not referenced loadByte function */ |
| static void near loadByte(void) { |
| asm { |
| PSHH |
| PSHX |
| #ifdef __HCS08__ |
| LDHX 5,SP |
| LDA 0,X |
| AIX #1 |
| STHX 5,SP |
| #else |
| LDA 5,SP |
| PSHA |
| LDX 7,SP |
| PULH |
| LDA 0,X |
| AIX #1 |
| STX 6,SP |
| PSHH |
| PULX |
| STX 5,SP |
| #endif |
| PULX |
| PULH |
| RTS |
| } |
| } |
| #endif /* __OPTIMIZE_FOR_SIZE__ */ |
| |
| |
| /*lint -esym(752,_COPY_L) inhibit message on dunction declared, but not used (it is used in HLI) */ |
| __EXTERN_C extern void _COPY_L(void); |
| /* DESC: copy very large structures (>= 256 bytes) in 16 bit address space (stack incl.) |
| IN: TOS count, TOS(2) @dest, H:X @src |
| OUT: |
| WRITTEN: X,H */ |
| #ifdef __ELF_OBJECT_FILE_FORMAT__ |
| #define toCopyDownBegOffs 0 |
| #else |
| #define toCopyDownBegOffs 2 /* for the hiware format, the toCopyDownBeg field is a long. Because the HC08 is big endian, we have to use an offset of 2 */ |
| #endif |
| static void Init(void) { |
| /* purpose: 1) zero out RAM-areas where data is allocated |
| 2) init run-time data |
| 3) copy initialization data from ROM to RAM |
| */ |
| /*lint -esym(529,p,i) inhibit warning about symbols not used: it is used in HLI below */ |
| int i; |
| int *far p; |
| |
| asm { |
| ZeroOut: ; |
| LDA _startupData.nofZeroOuts:1 ; nofZeroOuts |
| INCA |
| STA i:1 ; i is counter for number of zero outs |
| LDA _startupData.nofZeroOuts:0 ; nofZeroOuts |
| INCA |
| STA i:0 |
| LDHX _startupData.pZeroOut ; *pZeroOut |
| BRA Zero_5 |
| Zero_3: ; |
| ; CLR i:1 is already 0 |
| Zero_4: ; |
| ; { HX == _pZeroOut } |
| PSHX |
| PSHH |
| ; { nof bytes in (int)2,X } |
| ; { address in (int)0,X } |
| LDA 0,X |
| PSHA |
| LDA 2,X |
| INCA |
| STA p ; p:0 is used for high byte of byte counter |
| LDA 3,X |
| LDX 1,X |
| PULH |
| INCA |
| BRA Zero_0 |
| Zero_1: ; |
| ; CLRA A is already 0, so we do not have to clear it |
| Zero_2: ; |
| CLR 0,X |
| AIX #1 |
| Zero_0: ; |
| DBNZA Zero_2 |
| Zero_6: |
| DBNZ p, Zero_1 |
| PULH |
| PULX ; restore *pZeroOut |
| AIX #4 ; advance *pZeroOut |
| Zero_5: ; |
| DBNZ i:1, Zero_4 |
| DBNZ i:0, Zero_3 |
| ; |
| CopyDown: ; |
| |
| } |
| |
| /* copy down */ |
| /* _startupData.toCopyDownBeg ---> {nof(16) dstAddr(16) {bytes(8)}^nof} Zero(16) */ |
| #if defined(__OPTIMIZE_FOR_SIZE__) |
| asm { |
| #ifdef __HCS08__ |
| LDHX _startupData.toCopyDownBeg:toCopyDownBegOffs |
| PSHX |
| PSHH |
| #else |
| LDA _startupData.toCopyDownBeg:(1+toCopyDownBegOffs) |
| PSHA |
| LDA _startupData.toCopyDownBeg:(0+toCopyDownBegOffs) |
| PSHA |
| #endif |
| Loop0: |
| JSR loadByte ; load high byte counter |
| TAX ; save for compare |
| INCA |
| STA i |
| JSR loadByte ; load low byte counter |
| INCA |
| STA i:1 |
| DECA |
| BNE notfinished |
| CBEQX #0, finished |
| notfinished: |
| |
| JSR loadByte ; load high byte ptr |
| PSHA |
| PULH |
| JSR loadByte ; load low byte ptr |
| TAX ; HX is now destination pointer |
| BRA Loop1 |
| Loop3: |
| Loop2: |
| JSR loadByte ; load data byte |
| STA 0,X |
| AIX #1 |
| Loop1: |
| DBNZ i:1, Loop2 |
| DBNZ i:0, Loop3 |
| BRA Loop0 |
| |
| finished: |
| AIS #2 |
| }; |
| #else /* defined(__OPTIMIZE_FOR_SIZE__) time optimized asm version. */ |
| asm { |
| #ifdef __HCS08__ |
| LDHX _startupData.toCopyDownBeg:toCopyDownBegOffs |
| #else |
| LDX _startupData.toCopyDownBeg:(0+toCopyDownBegOffs) |
| PSHX |
| PULH |
| LDX _startupData.toCopyDownBeg:(1+toCopyDownBegOffs) |
| #endif |
| next: |
| LDA 0,X ; list is terminated by 2 zero bytes |
| ORA 1,X |
| BEQ copydone |
| PSHX ; store current position |
| PSHH |
| LDA 3,X ; psh dest low |
| PSHA |
| LDA 2,X ; psh dest high |
| PSHA |
| LDA 1,X ; psh cnt low |
| PSHA |
| LDA 0,X ; psh cnt high |
| PSHA |
| AIX #4 |
| JSR _COPY_L ; copy one block |
| PULH |
| PULX |
| TXA |
| ADD 1,X ; add low |
| PSHA |
| PSHH |
| PULA |
| ADC 0,X ; add high |
| PSHA |
| PULH |
| PULX |
| AIX #4 |
| BRA next |
| copydone: |
| }; |
| #endif /* defined(__OPTIMIZE_FOR_SIZE__) */ |
| |
| |
| /* FuncInits: for C++, this are the global constructors */ |
| #ifdef __cplusplus |
| #ifdef __ELF_OBJECT_FILE_FORMAT__ |
| i = (int)(_startupData.nofInitBodies - 1); |
| while (i >= 0) { |
| (&_startupData.initBodies->initFunc)[i](); /* call C++ constructors */ |
| i--; |
| } |
| #else /* __ELF_OBJECT_FILE_FORMAT__ */ |
| /* HIWARE object file format */ |
| if (_startupData.mInits != NULL) { |
| _PFunc *fktPtr; |
| fktPtr = _startupData.mInits; |
| while(*fktPtr != NULL) { |
| (**fktPtr)(); /* call constructor */ |
| fktPtr++; |
| } |
| } |
| #endif /* __ELF_OBJECT_FILE_FORMAT__ */ |
| #endif /* __cplusplus */ |
| |
| /* implement ROM libraries initialization here (see startup.c) */ |
| } |
| #endif /* __ONLY_INIT_SP */ |
| |
| __EXTERN_C extern void main(void); /* prototype of main function */ |
| |
| #pragma NO_EXIT |
| __EXTERN_C void _Startup(void) { |
| /* set the reset vector to _Startup in the linker parameter file (*.prm): |
| 'VECTOR 0 _Startup' |
| |
| purpose: 1) initialize the stack |
| 2) initialize run-time, ... |
| initialize the RAM, copy down init dat etc (Init) |
| 3) call main; |
| called from: _PRESTART-code generated by the Linker |
| */ |
| |
| INIT_SP_FROM_STARTUP_DESC(); |
| #ifndef __ONLY_INIT_SP |
| Init(); |
| #endif |
| __asm JMP main; /* with a C style main(); we would push the return address on the stack wasting 2 RAM bytes */ |
| } |