/* * This file is part of ixemul.library for the Amiga. * Copyright (C) 1991, 1992 Markus M. Wild * Portions Copyright (C) 1994 Rafael W. Luebbert * * 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 "../include/library_gl@TARGET@.h" #include "../include/version_gl@TARGET@.h" /* size of C_PRIVATE was generated by create_header.c */ /* include the generated header */ #include "../start/start_gl@TARGET@.h" .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 MesaGL@TARGET@_VERSION | UBYTE RT_VERSION .byte NT_LIBRARY | UBYTE RT_TYPE .byte MesaGL@TARGET@_PRIORITY | BYTE RT_PRI .long name@TARGET@ | APTR RT_NAME .long idString@TARGET@ | 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 name@TARGET@: .asciz MesaGL@TARGET@_NAME | this is an identifier tag to help in supporting the library | format is name version.revision (dd.mm.yy),,, | without any leading zeros in dd.mm.yy idString@TARGET@: .ascii MesaGL@TARGET@_IDSTRING .byte 13 .byte 10 .byte 0 | force word alignment .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 MesaGL@TARGET@BASE_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 _libOpen .long _libClose .long _libExpunge .long Null |------ my libraries definitions #define __reserved Null #define SYSTEM_CALL(func, vec) .long _##func #include "../include/GL/gl@TARGET@_calls.def" #undef SYSTEM_CALL |------ function table end marker .long -1 | 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, name@TARGET@) INITBYTE (MesaGL@TARGET@BASE_FLAGS, 0x6) | LIBF_CHANGED_SUMUSED INITWORD (MesaGL@TARGET@BASE_VERSION, MesaGL@TARGET@_VERSION) INITWORD (MesaGL@TARGET@BASE_REVISION, MesaGL@TARGET@_REVISION) INITLONG (MesaGL@TARGET@BASE_IDSTRING, idString@TARGET@) .long 0 | 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: |------ get the library pointer into a convenient A register movel a5,sp@- movel d0,a5 |------ save a pointer to our loaded code movel a0,a5@(MesaGL@TARGET@BASE_SEGLIST) |------ do the higher-level initialization in C |------ the MesaGL@TARGET@init function checks if the hardware is supported |------ (using 68000 instructions only) and if so will call MesaGL@TARGET@init() |------ for the main initialization. | pea a5@ | jsr _MesaGL@TARGET@init | addqw #4,sp 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... _libOpen: | ( libptr:a6, version:d0 ) |------ mark us as having another opener addqw #1,a6@(MesaGL@TARGET@BASE_OPENCNT) |------ prevent delayed expunges | !!!!!! | commo - example code uses private flags field (MesaGL@TARGET@BASE_MYFLAGS), WHY???? | !!!!!! bclr #LIBB_DELEXP,a6@(MesaGL@TARGET@BASE_FLAGS) |------ do other things in C | pea a6@ | jsr _MesaGL@TARGET@open | addqw #4,sp | beq OpenFailed |--- MesaGL@TARGET@open() should return the library base, if all ok rts OpenFailed: subqw #1,a6@(MesaGL@TARGET@BASE_OPENCNT) 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. _libClose: | ( libptr:a6 ) |------ do any cleanups needed in C | pea a6@ | jsr _MesaGL@TARGET@close | addqw #4,sp |------ mark us as having one fewer openers subqw #1,a6@(MesaGL@TARGET@BASE_OPENCNT) |------ see if there is anyone left with us open bne Null |------ see if we have a delayed expunge pending btst #LIBB_DELEXP,a6@(MesaGL@TARGET@BASE_FLAGS) | SEE ABOVE! bne _libExpunge | reserved entry Null: moveq #0,d0 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. _libExpunge: | ( libptr: a6 ) moveml a2/a5/a6,sp@- movel a6,a5 |------ assume we cant expunge subal a2,a2 bset #LIBB_DELEXP,a5@(MesaGL@TARGET@BASE_FLAGS) | SEE ABOVE !! |------ see if anyone has us open tstw a5@(MesaGL@TARGET@BASE_OPENCNT) bne L21 |------ go ahead and get rid of us. Store our seglist in a2 movel a5@(MesaGL@TARGET@BASE_SEGLIST),a2 movel 4:w,a6 |------ unlink from library list movel a5,a1 jsr a6@(_LVORemove) | | device specific closings here... | | pea a5@ | jsr _MesaGL@TARGET@expunge | addqw #4,sp |------ free our memory movel a5,a1 moveq #0,d0 movew a5@(MesaGL@TARGET@BASE_NEGSIZE),d0 subl d0,a1 addw a5@(MesaGL@TARGET@BASE_POSSIZE),d0 jsr a6@(_LVOFreeMem) L21: |------ set up our return value movel a2,d0 moveml sp@+,a2/a5/a6 rts