From d6b2bbaf1b5f86c29ddc20c5e698fa0f426a8e9a Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Wed, 18 Sep 1996 20:56:35 +0000 Subject: new files submitted by Craig Lebakken (lebakken@minn.net) and Derrick Ostertag (ostertag@transition.com) --- c/src/lib/start/a29k/crt0.s | 288 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 288 insertions(+) create mode 100644 c/src/lib/start/a29k/crt0.s (limited to 'c/src/lib/start/a29k/crt0.s') diff --git a/c/src/lib/start/a29k/crt0.s b/c/src/lib/start/a29k/crt0.s new file mode 100644 index 0000000000..017f2d4cca --- /dev/null +++ b/c/src/lib/start/a29k/crt0.s @@ -0,0 +1,288 @@ +; @(#)crt0.s 1.3 96/05/31 14:40:27, AMD +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +; Copyright 1988, 1989, 1990 Advanced Micro Devices, Inc. +; +; This software is the property of Advanced Micro Devices, Inc (AMD) which +; specifically grants the user the right to modify, use and distribute this +; software provided this notice is not removed or altered. All other rights +; are reserved by AMD. +; +; AMD MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS +; SOFTWARE. IN NO EVENT SHALL AMD BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL +; DAMAGES IN CONNECTION WITH OR ARISING FROM THE FURNISHING, PERFORMANCE, OR +; USE OF THIS SOFTWARE. +; +; So that all may benefit from your experience, please report any problems +; or suggestions about this software to the 29K Technical Support Center at +; 800-29-29-AMD (800-292-9263) in the USA, or 0800-89-1131 in the UK, or +; 0031-11-1129 in Japan, toll free. The direct dial number is 512-462-4118. +; +; Advanced Micro Devices, Inc. +; 29K Support Products +; Mail Stop 573 +; 5900 E. Ben White Blvd. +; Austin, TX 78741 +; 800-292-9263 +; +; /* $Id$ */ +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + + .file "crt0.s" + +; crt0.s version 3.3-0 +; +; This module gets control from the OS. +; It saves away the Am29027 Mode register settings and +; then sets up the pointers to the resident spill and fill +; trap handlers. It then establishes argv and argc for passing +; to main. It then calls _main. If main returns, it calls _exit. +; +; void = start( ); +; NOTE - not C callable (no lead underscore) +; + .include "sysmac.h" +; +; + .extern V_SPILL, V_FILL +; .comm __29027Mode, 8 ; A shadow of the mode register + .comm __LibInit, 4 + + .text + .extern _main, _exit, _atexit + + .word 0 ; Terminating tag word + .global start +start: + sub gr1, gr1, 6 * 4 + asgeu V_SPILL, gr1, rab ; better not ever happen + add lr1, gr1, 6 * 4 + +; +; Save the initial value of the Am29027's Mode register +; +; If your system does not enter crt0 with value for Am29027's Mode +; register in gr96 and gr97, and also the coprocessor is active +; uncomment the next 4 instructions. +; +; const gr96, 0xfc00820 +; consth gr96, 0xfc00820 +; const gr97, 0x1375 +; store 1, 3, gr96, gr97 +; +; const gr98, __29027Mode +; consth gr98, __29027Mode +; store 0, 0, gr96, gr98 +; add gr98, gr98, 4 +; store 0, 0, gr97, gr98 +; +; Now call the system to setup the spill and fill trap handlers +; + const lr3, spill + consth lr3, spill + const lr2, V_SPILL + syscall setvec + const lr3, fill + consth lr3, fill + const lr2, V_FILL + syscall setvec + +; +; atexit(_fini) +; +; const lr0, _atexit +; consth lr0, _atexit +; const lr2,__fini +; calli lr0,lr0 +; consth lr2,__fini +; +; Now call _init +; +; const lr0, __init +; consth lr0, __init +; calli lr0,lr0 +; nop + +; +; Get the argv base address and calculate argc. +; + syscall getargs + add lr3, v0, 0 ; argv + add lr4, v0, 0 + constn lr2, -1 +argcloop: ; scan for NULL terminator + load 0, 0, gr97, lr4 + add lr4, lr4, 4 + cpeq gr97, gr97, 0 + jmpf gr97, argcloop + add lr2, lr2, 1 +; +; Now call LibInit, if there is one. To aid runtime libraries +; that need to do some startup initialization, we have created +; a bss variable called LibInit. If the library doesn't need +; any run-time initialization, the variable is still 0. If the +; library does need run-time initialization, the library will +; contain a definition like +; void (*_LibInit)(void) = LibInitFunction; +; The linker will match up our bss LibInit with this data LibInit +; and the variable will not be 0. This results in the LibInit routine +; being called via the calli instruction below. +; + const lr0, __LibInit + consth lr0, __LibInit + load 0, 0, lr0, lr0 + cpeq gr96, lr0, 0 + jmpt gr96, NoLibInit + nop + calli lr0, lr0 + nop +NoLibInit: + +; +; Call RAMInit to initialize the data memory. +; +; The following code segment was used to create the two flavors of the +; run-time initialization routines (crt0_1.o, and crt0_2.o) as described +; in the User's Manual. If osboot is used to create a stand-alone +; application, or the call to RAMInit is made in the start-up routine, +; then the following is not needed. +; +; .ifdef ROM_LOAD +; .extern RAMInit +; +; const lr0, RAMInit +; consth lr0, RAMInit +; calli gr96, lr0 +; nop +; .else +; nop +; nop +; nop +; nop +; .endif + +; +; Uncomment the following .comm, if you ARE NOT using osboot as released +; with the High C 29K product, AND plan to use the romcoff utility to +; move code and/or data sections to ROM. +; +; .comm RAMInit, 4 +; +; Furthermore, if the above is uncommented, then use the following logic +; to call the RAMInit function, if needed. +; +; const lr0, RAMInit +; consth lr0, RAMInit +; load 0, 0, gr96, lr0 +; cpeq gr96, gr96, 0 ; nothing there? +; jmpt gr96, endRAMInit ; yes, nothing to init +; nop +; calli gr96, lr0 ; no, then instruction found +; nop ; execute function. +; + + +; +; call main, passing it 2 arguments. main( argc, argv ) +; + const lr0, _main + consth lr0, _main + calli lr0, lr0 + nop +; +; call exit +; + const lr0, _exit + consth lr0, _exit + calli lr0, lr0 + add lr2, gr96, 0 +; +; Should never get here, but just in case +; +loop: + syscall exit + jmp loop + nop + .sbttl "Spill and Fill trap handlers" + .eject +; +; SPILL, FILL trap handlers +; +; Note that these Spill and Fill trap handlers allow the OS to +; assume that the only registers of use are between gr1 and rfb. +; Therefore, if the OS desires to, it may simply preserve from +; lr0 for (rfb-gr1)/4 registers when doing a context save. +; +; +; Here is the spill handler +; +; spill registers from [*gr1..*rab) +; and move rab downto where gr1 points +; +; rab must change before rfb for signals to work +; +; On entry: rfb - rab = windowsize, gr1 < rab +; Near the end: rfb - rab > windowsize, gr1 == rab +; On exit: rfb - rab = windowsize, gr1 == rab +; + .global spill +spill: + sub tav, rab, gr1 ; tav = number of bytes to spill + srl tav, tav, 2 ; change byte count to word count + sub tav, tav, 1 ; make count zero based + mtsr CR, tav ; set Count Remaining register + sub tav, rab, gr1 + sub tav, rfb, tav ; pull down free bound and save it in rab + add rab, gr1, 0 ; first pull down allocate bound + storem 0, 0, lr0, tav ; store lr0..lr(tav) into rfb + jmpi tpc ; return... + add rfb, tav, 0 +; +; Here is the fill handler +; +; fill registers from [*rfb..*lr1) +; and move rfb upto where lr1 points. +; +; rab must change before rfb for signals to work +; +; On entry: rfb - rab = windowsize, lr1 > rfb +; Near the end: rfb - rab < windowsize, lr1 == rab + windowsize +; On exit: rfb - rab = windowsize, lr1 == rfb +; + .global fill +fill: + const tav, 0x80 << 2 + or tav, tav, rfb ; tav = ((rfb>>2) | 0x80)<<2 == [rfb]<<2 + mtsr IPA, tav ; ipa = [rfb]<<2 == 1st reg to fill + ; gr0 is now the first reg to fill + sub tav, lr1, rfb ; tav = number of bytes to fill + add rab, rab, tav ; push up allocate bound + srl tav, tav, 2 ; change byte count to word count + sub tav, tav, 1 ; make count zero based + mtsr CR, tav ; set Count Remaining register + loadm 0, 0, gr0, rfb ; load registers + jmpi tpc ; return... + add rfb, lr1, 0 ; ... first pushing up free bound + +; +; The __init function +; +; .sect .init,text +; .use .init +; .global __init +;__init: +; sub gr1,gr1,16 +; asgeu V_SPILL,gr1,gr126 +; add lr1,gr1,24 +; +; +; The __fini function +; +; .sect .fini,text +; .use .fini +; .global __fini +;__fini: +; sub gr1,gr1,16 +; asgeu V_SPILL,gr1,gr126 +; add lr1,gr1,24 +; + .end -- cgit v1.2.3