head 1.1; access; symbols version39-41:1.1; locks; comment @ * @; 1.1 date 92.05.18.12.31.18; author mwild; state Exp; branches; next ; desc @use new trace hooks (without TRACE_ACTION_JSR), and pass function address @ 1.1 log @Initial revision @ text @/* * This file is part of ixemul.library for the Amiga. * Copyright (C) 1991, 1992 Markus M. Wild * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #define START #include "ixemul.h" #undef DEBUG .text | The first executable location. This should return an error | in case someone tried to run you as a program (instead of | loading you as a library). .globl Start | we use this to force inclusion of start.s Start: movel #-1,d0 rts |----------------------------------------------------------------------- | A romtag structure. Both "exec" and "ramlib" look for | this structure to discover magic constants about you | (such as where to start running you from...). |----------------------------------------------------------------------- initDDescrip: |STRUCTURE RT,0 .word RTC_MATCHWORD | UWORD RT_MATCHWORD .long initDDescrip | APTR RT_MATCHTAG .long EndCode | APTR RT_ENDSKIP .byte RTF_AUTOINIT | UBYTE RT_FLAGS .byte IX_VERSION | UBYTE RT_VERSION .byte NT_LIBRARY | UBYTE RT_TYPE .byte IX_PRIORITY | BYTE RT_PRI .long ixName | APTR RT_NAME .long idString | APTR RT_IDSTRING .long Init | APTR RT_INIT | this is just fool proof, and this library will never make it to ROM | anyway, so resident tags are not that important ;-) EndCode: | this is the name that the library will have ixName: .asciz IX_NAME | this is an identifier tag to help in supporting the library | format is 'name version.revision (dd MON yyyy)',,, idString: .asciz IX_IDSTRING | force word allignment .even | The romtag specified that we were "RTF_AUTOINIT". This means | that the RT_INIT structure member points to one of these | tables below. If the AUTOINIT bit was not set then RT_INIT | would point to a routine to run. Init: .long IXBASE_SIZEOF | size of library base data space .long funcTable | pointer to function initializers .long dataTable | pointer to data initializers .long initRoutine | routine to run funcTable: |------ standard system routines .long Open .long Close .long Expunge .long Null |------ my libraries definitions #ifdef TRACE_LIBRARY #define SYSTEM_CALL(func, vec) .long trace_/**/func #else #define SYSTEM_CALL(func, vec) .long _/**/func #endif #include #undef SYSTEM_CALL |------ function table end marker .long -1 #ifdef TRACE_LIBRARY #define SYSTEM_CALL(func, vec) \ trace_/**/func: ; \ pea _/**/func; \ pea vec; \ jsr _trace_entry; \ lea sp@@(8),sp; \ tstl d0; \ beq 1f; /* jump directly there */ \ /* in that case, trace_entry already provided the result */ \ movel sp@@(-4),d0; \ rts; \ 1: jmp _/**/func; #include #undef SYSTEM_CALL #endif | The data table initializes static data structures. | The format is specified in exec/InitStruct routines | manual pages. The INITBYTE/INITWORD/INITLONG routines | are in the file "exec/initializers.i". The first argument | is the offset from the library base for this byte/word/long. | The second argument is the value to put in that cell. | The table is null terminated | NOTE - LN_TYPE below is a correction - old example had LH_TYPE dataTable: INITBYTE (LN_TYPE, NT_LIBRARY) INITLONG (LN_NAME, ixName) INITBYTE (IXBASE_FLAGS, LIBF_CHANGED_SUMUSED) INITWORD (IXBASE_VERSION, IX_VERSION) INITWORD (IXBASE_REVISION, IX_REVISION) INITLONG (IXBASE_IDSTRING, idString) .long 0 /* #ifdef DEBUG */ twoint: .asciz "$%lx, $%lx\n" /* #endif */ | This routine gets called after the library has been allocated. | The library pointer is in D0. The segment list is in A0. | If it returns non-zero then the library will be linked into | the library list. initRoutine: #ifdef DEBUG moveml d0/a0,sp@@- movel #twoint,sp@@- jsr _kprintf lea sp@@(4),sp moveml sp@@+,d0/a0 #endif |------ get the library pointer into a convenient A register movel a5,sp@@- movel d0,a5 |------ save a pointer to exec movel a6,a5@@(IXBASE_SYSLIB) |------ save a pointer to our loaded code movel a0,a5@@(IXBASE_SEGLIST) |------ do the higher-level initialization in C pea a5@@ jbsr _ix_init lea sp@@(4),sp #ifdef DEBUG movel d0,sp@@- movel d0,sp@@- movel #twoint,sp@@- jsr _kprintf lea sp@@(4),sp movel sp@@+,d0 movel sp@@+,d0 #endif movel sp@@+,a5 rts |---------------------------------------------------------------------- | | here begins the system interface commands. When the user calls | OpenLibrary/CloseLibrary/RemoveLibrary, this eventually gets translated | into a call to the following routines (Open/Close/Expunge). Exec | has already put our library pointer in A6 for us. Exec has turned | off task switching while in these routines (via Forbid/Permit), so | we should not take too long in them. | |---------------------------------------------------------------------- | Open returns the library pointer in d0 if the open | was successful. If the open failed then null is returned. | It might fail if we allocated memory on each open, or | if only open application could have the library open | at a time... Open: | ( libptr:a6, version:d0 ) #ifdef DEBUG moveml d0/a6,sp@@- movel #twoint,sp@@- jsr _kprintf lea sp@@(4),sp moveml sp@@+,d0/a6 #endif |------ mark us as having another opener addw #1,a6@@(IXBASE_OPENCNT) |------ prevent delayed expunges | !!!!!! | commo - example code uses private flags field (IXBASE_MYFLAGS), WHY???? | !!!!!! bclr #LIBB_DELEXP,a6@@(IXBASE_FLAGS) |------ do other things in C pea a6@@ jbsr _ix_open lea sp@@(4),sp |--- ix_open() should return the library base, if all ok rts | There are two different things that might be returned from | the Close routine. If the library is no longer open and | there is a delayed expunge then Close should return the | segment list (as given to Init). Otherwise close should | return NULL. Close: | ( libptr:a6 ) |------ do any cleanups needed in C pea a6@@ jbsr _ix_close lea sp@@(4),sp |------ set the return value clrl d0 |------ mark us as having one fewer openers subw #1,a6@@(IXBASE_OPENCNT) |------ see if there is anyone left with us open bne L11 |------ see if we have a delayed expunge pending btst #LIBB_DELEXP,a6@@(IXBASE_FLAGS) | SEE ABOVE! beq L11 |------ do the expunge bsr Expunge L11: rts | There are two different things that might be returned from | the Expunge routine. If the library is no longer open | then Expunge should return the segment list (as given to | Init). Otherwise Expunge should set the delayed expunge | flag and return NULL. | | One other important note: because Expunge is called from | the memory allocator, it may NEVER Wait() or otherwise | take long time to complete. Expunge: | ( libptr: a6 ) moveml d2/a5/a6,sp@@- movel a6,a5 movel a5@@(IXBASE_SYSLIB),a6 |------ see if anyone has us open tstw a5@@(IXBASE_OPENCNT) beq L21 |------ it is still open. set the delayed expunge flag bset #LIBB_DELEXP,a5@@(IXBASE_FLAGS) | SEE ABOVE !! clrl d0 bra Expunge_End L21: |------ go ahead and get rid of us. Store our seglist in d2 movel a5@@(IXBASE_SEGLIST),d2 |------ unlink from library list movel a5,a1 jsr a6@@(_LVORemove) | | device specific closings here... | pea a5@@ jbsr _ix_expunge lea sp@@(4),sp |------ free our memory clrl d0 movel a5,a1 movew a5@@(IXBASE_NEGSIZE),d0 subl d0,a1 addw a5@@(IXBASE_POSSIZE),d0 jsr a6@@(_LVOFreeMem) |------ set up our return value movel d2,d0 Expunge_End: moveml sp@@+,d2/a5/a6 rts Null: clrl d0 rts @