head 1.1; access; symbols version39-41:1.1; locks; comment @ * @; 1.1 date 92.05.14.20.36.14; author mwild; state Exp; branches; next ; desc @trap handlers and glue code @ 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. * * $Id$ * * $Log$ */ .globl _trap_00 .globl _trap_20 .globl _restore_00 .globl _restore_20 .globl _supervisor .globl _do_sigreturn .globl _sup00_do_sigreturn .globl _sup20_do_sigreturn .globl _sup00_do_sigreturn_ssp .globl _sup20_do_sigreturn_ssp .globl _launch_glue .globl _addupc #undef DEBUG | | ATTENTION: | | do_sigreturn() uses absolute offsets into struct user. | if you change struct user, be sure to check whether the current | offsets of p_sigmask and u_onstack are still valid !!!! | | This is the trap processing function for the mc68000. | Things are quite easy here, just save the general purpose registers | and the pc/sr combo, call trap(), then restore the previous | context and return _trap_00: movel a5,sp@@- | need a scratch register movel usp,a5 | get usp moveml d0-d7/a0-a6,a5@@-| store registers on usp movel sp@@+,a5@@(0x34) | insert the saved a5 into the saveset movel sp@@+,d2 | remember trapnumber movew sp@@+,a5@@- | copy SR movel sp@@+,a0 | remember and movel a0,a5@@- | copy offending PC | | pass return address and ssp-value on userstack | This happens for the same reason as we have a glue_launch entry. | trap cleans up these 8 bytes on the user stack itself movel sp,a5@@- movel #_restore_00,a5@@- movel a5,usp | and remember current value of usp (a5) | fine, now process this trap. This might (doesn't have to) push | additional frames. If not, we just return where the exception | took place (and probably will again...) movel a0,sp@@- | pass offending address (don't know more about it) addl d2,d2 | convert the passed trap number into a fake addl d2,d2 | 68020 frame format word movel d2,sp@@- | and pass it as argument jsr _trap | to the higher level C trap lea sp@@(8),sp | processor _restore_00: movel usp,a5 | get usp lea a5@@(0x42),a1 | skip over the now no longer needed frame movel a1,usp | -> 15 registers, one PC and one SR | set up the original supervisor stack frame movel a5@@+,sp@@- | PC movew a5@@+,sp@@- | SR moveml a5@@,d0-d7/a0-a6 | and the other cpu registers rte | This is the trap processor for the mc68020 and above, paired with | an fpu (don't *need* an fpu though). | What is done: start is same as with 68000, but then the complete | additional exception frame is saved on the usp, together with the | fpu state. Then trap() is called, and then the previous context | is restored (involves copying back the frame from the usp over to the ssp) _trap_20: movel a5,sp@@ | nuke the trap number, we use the frame format word movel usp,a5 | get usp moveml d0-d7/a0-a6,a5@@-| store registers on usp movel sp@@+,a5@@(0x34) | insert the saved a5 into the saveset movew sp@@+,a5@@- | copy SR movel sp@@+,d2 | remember and movel d2,a5@@- | copy (offending?) PC | find out more about the frame (according to the MC68030 user manual) clrl d1 movew sp@@+,d1 | remember frame format word movew d1,d0 andw #0xf000,d0 beq Lfmt_S0 | S0 cmpw #0x1000,d0 beq Lfmt_S1 | S1 this (interrupt) frame shouldn't be here... cmpw #0x2000,d0 beq Lfmt_S2 | CHK{2},cpTRAPcc,TRAPV,Trace,Div0,MMUcfg,cp post instr cmpw #0x9000,d0 beq Lfmt_S9 | cp mid instr,main det prot viol,int during cp instr cmpw #0xa000,d0 beq Lfmt_SA_SB | address or bus error, short and long frame cmpw #0xb000,d0 bne Lfmt_S0 | ??? frame, this will probably not fully cleanup sp.. Lfmt_SA_SB: | this part (upto Lbe10) inspired by locore.s in sys/hp300/ of BSD4.3-reno movew sp@@(2),d0 | grab SSW for fault processing btst #12,d0 | RB set? beq LbeX0 | no, test RC bset #14,d0 | yes, must set FB movew d0,sp@@(2) | for hardware too LbeX0: btst #13,d0 | RC set? beq LbeX1 | no, skip bset #15,d0 | yes, must set FC movew d0,sp@@(2) | for hardware too LbeX1: btst #8,d0 | data fault? beq Lbe0 | no, check for hard cases movel sp@@(8),d2 | fault address is as given in frame bra Lbe10 | thats it Lbe0: btst #12,d1 | long (type B) stack frame? bne Lbe4 | yes, go handle btst #14,d0 | no, can use saved PC. FB set? beq Lbe3 | no, try FC addql #4,d2 | yes, adjust address bra Lbe10 | done Lbe3: btst #15,d0 | FC set? beq Lbe10 | no, done addql #2,d2 | yes, adjust address bra Lbe10 | done Lbe4: movel sp@@(28),d2 | long format, use stage B address btst #15,d0 | FC set? beq Lbe10 | no, all done subql #2,d2 | yes, adjust address Lbe10: | now move the frame over to the usp (6/21 longwords remain) moveml sp@@+,d3-d7/a0 | may trash as many registers as I like, I saved moveml d3-d7/a0,a5@@- | them already ;-) First copy 6 longs btst #12,d1 | long (type B) stack frame? beq Lfmt_S0 | nope, done moveml sp@@+,d3-d7/a0-a2 | first copy 8 longs moveml d3-d7/a0-a2,a5@@- moveml sp@@+,d3-d7/a0-a1 | plus 7 gives 15, plus already stored 6 is 21 moveml d3-d7/a0-a1,a5@@- bra Lfmt_S0 | finito Lfmt_S9: movel sp@@+,a5@@- | S9 is an S2 plus 4 internal (word length) registers movel sp@@+,a5@@- | so store those registers, and fall into S2 Lfmt_S2: movel sp@@+,d2 | S2 contains the offending instruction address | and the frame format word movel d2,a5@@- | we have the offending instruction address here | fall into Lfmt_S0: Lfmt_S1: movew d1,a5@@- | and as the last thing store the frame format word | | now lets look at the fpu, if there is an fpu in the system | btst #4,(4)@@(0x129) | is AFB_68881 set in SysBase->AttnFlags ?? beq Lno_fpu fsave a5@@- | dump the fpu state onto the usp moveb a5@@,d0 | and get the fpu state identifier beq Lno_fpu | null frame? clrl d0 moveb a5@@(1),d0 | load state frame size bset #3,a5@@(d0) | set bit 27 of BIU fmovemx fp0-fp7,a5@@- | push the fpu data registers and fmoveml fpcr/fpsr/fpi,a5@@- | fpu control registers movew #-1,a5@@- | mark that there is fpu stuff on the stack Lno_fpu: | | pass return address and ssp-value on userstack | This happens for the same reason as we have a glue_launch entry. | trap cleans up these 8 bytes on the user stack itself movel sp,a5@@- movel #_restore_20,a5@@- movel a5,usp | set the new value of the usp | that's it, phew.. now process this frame, and perhaps throw some | frames on it as well to deal with the signal movel d2,sp@@- | pass offending PC movel d1,sp@@- | pass frame format word jsr _trap | do distribution in C ;-) lea sp@@(8),sp _restore_20: | | restore the saved stack frame from the usp, and copy the necessary | parts over to the ssp | movel usp,a5 | first deal with fpu stuff, if there's an fpu btst #4,(4)@@(0x129) | is AFB_68881 set in SysBase->AttnFlags ?? beq Lno_fpu2 tstb a5@@ beq Lrst_fpu_frame | there's only the null frame, go and restore it lea a5@@(2),a5 | skip fpu indicator fmoveml a5@@+,fpcr/fpsr/fpi | restore fpu control and fmovemx a5@@+,fp0-fp7 | fpu data registers Lrst_fpu_frame: frestore a5@@+ | and restore the internal fpu state Lno_fpu2: movew a5@@+,d1 | get frame format word movew d1,d0 andw #0xf000,d0 beq Lrfmt_S0 | S0 cmpw #0x1000,d0 beq Lrfmt_S1 | S1 cmpw #0x2000,d0 beq Lrfmt_S2 | S2 cmpw #0x9000,d0 beq Lrfmt_S9 | S9 cmpw #0xa000,d0 beq Lrfmt_SA | SA cmpw #0xb000,d0 bne Lrfmt_S0 | ??? frame Lrfmt_SB: moveml a5@@+,d3-d7/a0-a2 moveml d3-d7/a0-a2,sp@@- moveml a5@@+,d3-d7/a0-a1 moveml d3-d7/a0-a1,sp@@- | copy 15 longs Lrfmt_SA: movel a5@@+,sp@@- | copy 3 longs movel a5@@+,sp@@- movel a5@@+,sp@@- Lrfmt_S9: movel a5@@+,sp@@- | copy 2 longs movel a5@@+,sp@@- Lrfmt_S2: movel a5@@+,sp@@- | copy 1 long Lrfmt_S1: Lrfmt_S0: movew d1,sp@@- | insert frame format word movel a5@@+,sp@@- | copy PC movew a5@@+,sp@@- | and SR lea a5@@(0x3c),a1 | skip the rest of the frame movel a1,usp | 0x3c -> 15 registers moveml a5@@,d0-d7/a0-a6 | restore the cpu registers rte | that's it (finally) .. | | jump to the given argument in supervisor mode | does NOT return | _supervisor: movel sp@@(4),a5 | where to go in supervisor movel sp@@(8),sp@@- | with this usp movel a6,sp@@- movel 4:w,a6 jmp a6@@(-0x1e) | do it (Supervisor() system call) | | restore signal context | argument comes in usp | | mc68020 entry _sup20_do_sigreturn_ssp: | entry via jsr from supervisor mode movel sp@@(4),sp | set ssp _sup20_do_sigreturn: lea sp@@(-8),sp | make room for an exception frame movew #0x20,sp@@(6) | fake format word bra fromsup_sigreturn | mc68000 entry _sup00_do_sigreturn_ssp: movel sp@@(4),sp | set ssp _sup00_do_sigreturn: lea sp@@(-6),sp | make room for an exception frame fromsup_sigreturn: moveml d0/d1/a0/a1,sp@@- movel usp,a0 | get signal context bra resume_sigreturn | fall into _do_sigreturn | Supervisor() entry (already comes on exception frame) _do_sigreturn: | make the sigreturn() function preserve all registers moveml d0/d1/a0/a1,sp@@- movel usp,a0 | get signal context movel a0@@+,a6 | restore the trashed a6 register movel a0@@,a0 resume_sigreturn: #if 0 movel sp,a0@@- movel a0,sp pea dumpsc_msg jsr _kprintf movel sp@@(4),sp movel usp,a0 #endif movel 4:w,a1 | SysBase movel a1,d1 | remember for later setting of sc_ap movel a1@@(0x114),a1 | ThisTask movel a1@@(0x2e),a1 | TrapData -> (struct user *) | ok, now a0:sc, a1:u | get those offsets in struct user with `print_user.c' ! movel a0@@+,a1@@(0x11c) | u.u_onstack = sc->sc_onstack movel a0@@+,a1@@(0x134) | u.p_sigmask = sc->sc_mask movel a0@@+,a1 | usp = sc->sc_sp movel a1,usp movel a0@@+,a5 | fp = sc->sc_fp #if 0 moveml d1/a0/a1,sp@@- movel a0@@,sp@@- pea before_foo jsr _kprintf lea sp@@(8),sp moveml sp@@+,d1/a0/a1 #endif movel d1,a1 | get back SysBase movel a1@@(0x114),a1 | ThisTask movel a0@@,a1@@(0x0e) | store Flags,State,IDNestCnt,TDNestCnt movel d1,a1 lea a0@@(2),a0 | skip unused part of sc_ap movew a0@@+,d1 | get IDNestCnt and TDNestCnt movew d1,a1@@(0x126) | store them in SysBase tstb a1@@(0x126) bmi Lenable Ldisabled: movew #0x4000,0xdff09a | disable interrupts bra Lint_twiddle Lenable: movew #0xc000,0xdff09a | enable interrupts Lint_twiddle: #if 0 moveml d1/a0/a1,sp@@- pea after_foo jsr _kprintf lea sp@@(4),sp moveml sp@@+,d1/a0/a1 #endif | set pc and sr in current exception frame movel a0@@+,sp@@(2+4*4) | set PC movew a0@@(2),sp@@(4*4) | and SR #ifdef DEBUG pea sp@@ pea dumpframe_msg jsr _kprintf lea sp@@(8),sp #endif moveml sp@@+,d0/d1/a0/a1 rte #ifdef DEBUG dumpsc_msg: .asciz "ssp = $%lx, onstack = %ld, mask = $%lx, sp = $%lx\nfp = $%lx, ap = $%lx, pc = $%lx, ps = $%lx\n" dumpframe_msg: .asciz "restore: ssp = $%lx, sr = $%x, pc = $%lx, fmt = $%x.\n" before_foo: .asciz "before foo ($%lx), " after_foo: .asciz "after foo.\n" .even #endif | | launch_glue is used to invoke the sig_launch handler. We have to care to | clean the supervisor stack, if we should call a signal handler from | the launch handler. | The bad thing is, that doing this right needs information on how | the tc_Launch entry is called from the OS. Thus I pass two parameters | on the user stack, the value of the `virgin' ssp and the value of | a4, which happens to contain the address of the context restore | function. | It is assumed, that tc_Launch is called via | ... jsr sub | ... | sub:jsr tc_Launch | Thus we have to backup the sp by two jsr's, which is 8. _launch_glue: movel 4:w,a0 movel a0@@(0x114),a0 | tid = SysBase->ThisTask movel a0@@(0x36),a0 | usp isn't setup correctly, do it now from tc_SPReg movel sp,a0@@- addl #8,a0@@ movel a4,a0@@- movel a0,usp jsr _sig_launch | sig_launch `(void *pc_ret, *ssp_ret)' (`' on usp) | sig_launch() already corrects the usp to pop those two arguments rts /* * update profiling information for the user * addupc(pc, &u.u_prof, ticks) */ _addupc: movl a2,sp@@- | scratch register movl sp@@(12),a2 | get &u.u_prof movl sp@@(8),d0 | get user pc subl a2@@(8),d0 | pc -= pr->pr_off jlt Lauexit | less than 0, skip it movl a2@@(12),d1 | get pr->pr_scale lsrl #1,d0 | pc /= 2 lsrl #1,d1 | scale /= 2 | mulul d1,d0 | pc /= scale moveml d0/d1,sp@@- jbsr ___mulsi3 lea sp@@(8),sp moveq #14,d1 lsrl d1,d0 | pc >>= 14 bclr #0,d0 | pc &= ~1 cmpl a2@@(4),d0 | too big for buffer? jge Lauexit | yes, screw it addl a2@@,d0 | no, add base | movl d0,sp@@- | push address | jbsr _fusword | grab old value | movl sp@@+,a0 | grab address back | cmpl #-1,d0 | access ok | jeq Lauerror | no, skip out movel d0,a0 movew a0@@,d0 addw sp@@(18),d0 | add tick to current value movew d0,a0@@ | movl d0,sp@@- | push value | movl a0,sp@@- | push address | jbsr _susword | write back new value | addql #8,sp | pop params | tstl d0 | fault? | jeq Lauexit | no, all done Lauerror: | clrl a2@@(12) | clear scale (turn off prof) Lauexit: movl sp@@+,a2 | restore scratch reg rts @