Clarify duties of traps 1, 2, 12, 15 for emulations
Include <m68k/m68k/sigreturn.s> code. Add/fix some comments...
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gwr
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4756c63625
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a9bc70551a
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@ -1,4 +1,4 @@
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/* $NetBSD: locore.s,v 1.45 1997/02/11 00:05:01 gwr Exp $ */
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/* $NetBSD: locore.s,v 1.46 1997/03/11 22:58:57 gwr Exp $ */
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/*
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* Copyright (c) 1994, 1995 Gordon W. Ross
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@ -104,9 +104,11 @@ L_high_code:
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| just before the start of the kernel text segment, so the
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| kernel can sanity-check the DDB symbols at [end...esym].
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| Pass the struct exec at tmpstk-32 to __bootstrap().
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| Also, make sure the initial frame pointer is zero so that
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| the backtrace algorithm used by KGDB terminates nicely.
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lea tmpstk-32, sp
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movl #0,a6
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jsr __bootstrap | See sun3_startup.c
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jsr __bootstrap | See _startup.c
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| Now that __bootstrap() is done using the PROM setcxsegmap
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| we can safely set the sfc/dfc to something != FC_CONTROL
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@ -144,9 +146,9 @@ L_high_code:
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lea _proc0,a0 | proc0.p_md.md_regs =
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movl a1,a0@(P_MDREGS) | trapframe
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movl a2,a1@(FR_SP) | a2 == usp (from above)
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pea a1@ |
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pea a1@ | push &trapframe
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jbsr _main | main(&trapframe)
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addql #4,sp | help backtrace work
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addql #4,sp | help DDB backtrace
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trap #15 | should not get here
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| This is used by cpu_fork() to return to user mode.
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@ -443,66 +445,50 @@ _trap0:
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jra rei | all done
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/*
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* Trap 1 is either:
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* sigreturn (native NetBSD executable)
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* breakpoint (HPUX executable)
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* Trap 1 action depends on the emulation type:
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* NetBSD: sigreturn "syscall"
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* HPUX: user breakpoint
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*/
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_trap1:
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#if 0 /* COMPAT_HPUX */
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/* If process is HPUX, this is a user breakpoint. */
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jne trap15 | breakpoint
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jne _trap15 | HPUX user breakpoint
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#endif
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/* fall into sigreturn */
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jra sigreturn | NetBSD
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/*
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* The sigreturn() syscall comes here. It requires special handling
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* because we must open a hole in the stack to fill in the (possibly much
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* larger) original stack frame.
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*/
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sigreturn:
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lea sp@(-84),sp | leave enough space for largest frame
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movl sp@(84),sp@ | move up current 8 byte frame
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movl sp@(88),sp@(4)
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movl #84,sp@- | default: adjust by 84 bytes
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moveml #0xFFFF,sp@- | save user registers
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movl usp,a0 | save the user SP
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movl a0,sp@(FR_SP) | in the savearea
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movl #SYS_sigreturn,sp@- | push syscall number
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jbsr _syscall | handle it
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addql #4,sp | pop syscall#
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movl sp@(FR_SP),a0 | grab and restore
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movl a0,usp | user SP
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lea sp@(FR_HW),a1 | pointer to HW frame
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movw sp@(FR_ADJ),d0 | do we need to adjust the stack?
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jeq Lsigr1 | no, just continue
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moveq #92,d1 | total size
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subw d0,d1 | - hole size = frame size
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lea a1@(92),a0 | destination
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addw d1,a1 | source
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lsrw #1,d1 | convert to word count
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subqw #1,d1 | minus 1 for dbf
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Lsigrlp:
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movw a1@-,a0@- | copy a word
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dbf d1,Lsigrlp | continue
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movl a0,a1 | new HW frame base
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Lsigr1:
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movl a1,sp@(FR_SP) | new SP value
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moveml sp@+,#0x7FFF | restore user registers
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movl sp@,sp | and our SP
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jra rei | all done
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/*
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* Trap 2 is one of:
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* NetBSD: not used (ignore)
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* SunOS: Some obscure FPU operation
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* HPUX: sigreturn
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* Trap 2 action depends on the emulation type:
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* NetBSD: user breakpoint -- See XXX below...
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* SunOS: cache flush
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* HPUX: sigreturn
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*/
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_trap2:
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#if 0 /* COMPAT_HPUX */
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/* XXX: If HPUX, this is a user breakpoint. */
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/* If process is HPUX, this is a sigreturn call */
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jne sigreturn
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#endif
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/* fall into trace (NetBSD or SunOS) */
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jra _trap15 | NetBSD user breakpoint
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| XXX - Make NetBSD use trap 15 for breakpoints?
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| XXX - That way, we can allow this cache flush...
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| XXX SunOS trap #2 (and NetBSD?)
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| Flush on-chip cache (leave it enabled)
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| movl #IC_CLEAR,d0
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| movc d0,cacr
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| rte
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/*
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* Trap 12 is the entry point for the cachectl "syscall"
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* cachectl(command, addr, length)
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* command in d0, addr in a1, length in d1
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*/
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.globl _cachectl
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_trap12:
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movl d1,sp@- | push length
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movl a1,sp@- | push addr
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movl d0,sp@- | push command
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jbsr _cachectl | do it
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lea sp@(12),sp | pop args
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jra rei | all done
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/*
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* Trace (single-step) trap. Kernel-mode is special.
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@ -512,9 +498,8 @@ _trace:
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clrl sp@- | stack adjust count
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moveml #0xFFFF,sp@-
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moveq #T_TRACE,d0
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movw sp@(FR_HW),d1 | get PSW
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andw #PSL_S,d1 | from system mode?
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jne kbrkpt | yes, kernel breakpoint
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btst #5,sp@(FR_HW) | was supervisor mode?
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jne kbrkpt | yes, kernel brkpt
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jra fault | no, user-mode fault
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/*
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@ -522,18 +507,18 @@ _trace:
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* - GDB breakpoints (in user programs)
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* - KGDB breakpoints (in the kernel)
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* - trace traps for SUN binaries (not fully supported yet)
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* User mode traps are passed simply passed to trap()
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* User mode traps are simply passed to trap().
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*/
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_trap15:
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clrl sp@- | stack adjust count
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moveml #0xFFFF,sp@-
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moveq #T_TRAP15,d0
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movw sp@(FR_HW),d1 | get PSW
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andw #PSL_S,d1 | from system mode?
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jne kbrkpt | yes, kernel breakpoint
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btst #5,sp@(FR_HW) | was supervisor mode?
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jne kbrkpt | yes, kernel brkpt
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jra fault | no, user-mode fault
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kbrkpt: | Kernel-mode breakpoint or trace trap. (d0=trap_type)
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kbrkpt:
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| Kernel-mode breakpoint or trace trap. (d0=trap_type)
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| Save the system sp rather than the user sp.
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movw #PSL_HIGHIPL,sr | lock out interrupts
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lea sp@(FR_SIZE),a6 | Save stack pointer
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@ -555,7 +540,7 @@ Lbrkpt1:
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bgt Lbrkpt1
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Lbrkpt2:
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| Call the special kernel debugger trap handler.
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| Call the trap handler for the kernel debugger.
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| Do not call trap() to handle it, so that we can
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| set breakpoints in trap() if we want. We know
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| the trap type is either T_TRACE or T_BREAKPOINT.
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@ -576,19 +561,8 @@ Lbrkpt2:
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movl sp@,sp | ... and sp
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rte | all done
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/*
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* Trap 12 is the entry point for the cachectl "syscall"
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* cachectl(command, addr, length)
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* command in d0, addr in a1, length in d1
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*/
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.globl _cachectl
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_trap12:
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movl d1,sp@- | push length
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movl a1,sp@- | push addr
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movl d0,sp@- | push command
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jbsr _cachectl | do it
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lea sp@(12),sp | pop args
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jra rei | all done
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/* Use common m68k sigreturn */
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#include <m68k/m68k/sigreturn.s>
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/*
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* Interrupt handlers. Most are auto-vectored,
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@ -1030,22 +1004,31 @@ Lswnofpsave:
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movl a0@(P_ADDR),a1 | get p_addr
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movl a1,_curpcb
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/* see if pmap_activate needs to be called; should remove this */
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movl a0@(P_VMSPACE),a2 | a2 = p->p_vmspace
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/*
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* Load the new VM context (new MMU root pointer)
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*/
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movl a0@(P_VMSPACE),a2 | vm = p->p_vmspace
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#ifdef DIAGNOSTIC
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tstl a2 | map == VM_MAP_NULL?
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jeq Lbadsw | panic
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#endif
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| Important note: We MUST call pmap_activate to set the
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| MMU context register (like setting a root table pointer).
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| XXX - Eventually, want to do that here, inline.
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lea a2@(VM_PMAP),a2 | pmap = &vmspace.vm_pmap
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#if 1 /* XXX: PMAP_DEBUG */
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/*
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* Just call pmap_activate() for now. Later on,
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* use the in-line version below (for speed).
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*/
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lea a2@(VM_PMAP),a2 | pmap = &vmspace.vm_pmap
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pea a2@ | push pmap
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jbsr _pmap_activate | pmap_activate(pmap)
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addql #4,sp
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movl _curpcb,a1 | restore p_addr
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| Note: pmap_activate will clear the cache if needed.
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#else
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/* XXX - Later, use this unfinished inline.. */
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XXX XXX (PM_CTXNUM)
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movl #IC_CLEAR,d0
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movc d0,cacr | invalidate cache(s)
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#endif
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/*
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* Reload the registers for the new process.
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