/* $NetBSD: locore.s,v 1.15 2024/01/19 05:46:36 thorpej Exp $ */ /* * Copyright (c) 1988 University of Utah. * Copyright (c) 1980, 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: Utah $Hdr: locore.s 1.66 92/12/22$ * * @(#)locore.s 8.6 (Berkeley) 5/27/94 */ #include "opt_compat_netbsd.h" #include "opt_compat_sunos.h" #include "opt_fpsp.h" #include "opt_ddb.h" #include "opt_kgdb.h" #include "opt_lockdebug.h" #include "opt_m68k_arch.h" #include "assym.h" #include #include #include "ksyms.h" /* * Memory starts at 0x0000.0000, and we have linked the kernel * at 0x0000.2000 to ensure that VA==0 is unmapped once we turn * on the MMU. We arrive here running VA==PA and with the MMU * disabled. * * This first 8KB of RAM at PA==0 won't go to waste, though; we * will use it for the kernel message buffer. */ /* * Temporary stack for a variety of purposes. * Try and make this the first thing is the data segment so it * is page aligned. Note that if we overflow here, we run into * our text segment. */ .data .space PAGE_SIZE ASLOCAL(tmpstk) /* * Macro to relocate a symbol, used before MMU is enabled. */ #define _RELOC(var, ar) \ lea var,ar #define RELOC(var, ar) _RELOC(_C_LABEL(var), ar) #define ASRELOC(var, ar) _RELOC(_ASM_LABEL(var), ar) BSS(esym,4) .globl _C_LABEL(edata) .globl _C_LABEL(etext),_C_LABEL(end) /* * This is for kvm_mkdb, and should be the address of the beginning * of the kernel text segment (not necessarily the same as kernbase). */ .text GLOBAL(kernel_text) /* * start of kernel and .text! */ ASENTRY_NOPROFILE(start) movw #PSL_HIGHIPL,%sr | no interrupts movl #0,%a5 | RAM starts at 0 (a5) ASRELOC(tmpstk, %a0) movl %a0,%sp | give ourselves a temporary stack RELOC(edata,%a0) | clear out BSS movl #_C_LABEL(end) - 4, %d0 | (must be <= 256 kB) subl #_C_LABEL(edata), %d0 lsrl #2,%d0 1: clrl %a0@+ dbra %d0,1b /* * Qemu does not pass us the symbols, so leave esym alone. * The bootinfo immediately follows the kernel. Go parse * it to get CPU/FPU/MMU information and figure out where * the end of the loaded image really is. */ RELOC(bootinfo_start,%a0) movl #_C_LABEL(end),%sp@- jbsr %a0@ | bootinfo_start(end) addql #4,%sp /* XXX XXX XXX */ movl #CACHE_OFF,%d0 movc %d0,%cacr | clear and disable on-chip cache(s) /* XXX XXX XXX */ /* initialize source/destination control registers for movs */ moveq #FC_USERD,%d0 | user space movc %d0,%sfc | as source movc %d0,%dfc | and destination of transfers /* * bootinfo_start() recorded the first PA following the * bootinfo in bootinfo_end. That represents the end of * the loaded image. Rounding that to a page gives us * the first free physical page. */ RELOC(bootinfo_end,%a0) movl %a0@,%d2 addl #PAGE_SIZE-1,%d2 andl #PG_FRAME,%d2 | round to a page movl %d2,%a4 addl %a5,%a4 | convert to PA pea %a5@ | firstpa pea %a4@ | nextpa RELOC(pmap_bootstrap,%a0) jbsr %a0@ | pmap_bootstrap(firstpa, nextpa) addql #8,%sp /* * Enable the MMU. * Since the kernel is mapped logical == physical, we just turn it on. */ RELOC(Sysseg_pa, %a0) | system segment table addr movl %a0@,%d1 | read value (a PA) RELOC(mmutype, %a0) cmpl #MMU_68040,%a0@ | 68040? jne Lmotommu1 | no, skip .long 0x4e7b1807 | movc d1,srp jra Lstploaddone Lmotommu1: #ifdef M68030 RELOC(protorp, %a0) movl %d1,%a0@(4) | segtable address pmove %a0@,%srp | load the supervisor root pointer #endif /* M68030 */ Lstploaddone: RELOC(mmutype, %a0) cmpl #MMU_68040,%a0@ | 68040? jne Lmotommu2 | no, skip movl #VIRT68K_TT40_IO,%d0 | DTT0 maps the I/O space .long 0x4e7b0006 | movc d0,dtt0 moveq #0,%d0 | ensure the other TT regs are disabled .long 0x4e7b0004 | movc d0,itt0 .long 0x4e7b0005 | movc d0,itt1 .long 0x4e7b0007 | movc d0,dtt1 .word 0xf4d8 | cinva bc .word 0xf518 | pflusha movl #MMU40_TCR_BITS,%d0 .long 0x4e7b0003 | movc d0,tc #ifdef M68060 RELOC(cputype, %a0) cmpl #CPU_68060,%a0@ | 68060? jne Lnot060cache movl #1,%d0 .long 0x4e7b0808 | movcl d0,pcr movl #0xa0808000,%d0 movc %d0,%cacr | enable store buffer, both caches jmp Lenab1 Lnot060cache: #endif movl #0x80008000,%d0 movc %d0,%cacr | turn on both caches jmp Lenab1 Lmotommu2: movl #VIRT68K_TT30_IO,%sp@- | TT0 maps the I/O space .long 0xf0170800 | pmove %sp@,%tt0 clrl %sp@ | ensure TT1 is disabled .long 0xf0170c00 | pmove %sp@,%tt1 pflusha movl #MMU51_TCR_BITS,%sp@ | value to load TC with pmove %sp@,%tc | load it /* * Should be running mapped from this point on */ Lenab1: lea _ASM_LABEL(tmpstk),%sp | re-load the temporary stack jbsr _C_LABEL(vec_init) | initialize the vector table /* call final pmap setup */ jbsr _C_LABEL(pmap_bootstrap_finalize) /* set kernel stack, user SP */ movl _C_LABEL(lwp0uarea),%a1 | get lwp0 uarea lea %a1@(USPACE-4),%sp | set kernel stack to end of area movl #USRSTACK-4,%a2 movl %a2,%usp | init user SP tstl _C_LABEL(fputype) | Have an FPU? jeq Lenab2 | No, skip. clrl %a1@(PCB_FPCTX) | ensure null FP context movl %a1,%sp@- jbsr _C_LABEL(m68881_restore) | restore it (does not kill a1) addql #4,%sp Lenab2: cmpl #MMU_68040,_C_LABEL(mmutype) | 68040? jeq Ltbia040 | yes, cache already on pflusha movl #CACHE_ON,%d0 movc %d0,%cacr | clear cache(s) jra Lenab3 Ltbia040: .word 0xf518 Lenab3: /* * final setup for C code: * Create a fake exception frame so that cpu_lwp_fork() can copy it. * main() nevers returns; we exit to user mode from a forked process * later on. */ jbsr _C_LABEL(virt68k_init) | additional pre-main initialization #if 0 /* * XXX Don't do the spl0() here; when Qemu performs a reboot request, * XXX it seems to not clear pending interrupts, and so we blow up * XXX early when the new kernel starts up. */ movw #PSL_LOWIPL,%sr | lower SPL #endif clrw %sp@- | vector offset/frame type clrl %sp@- | PC - filled in by "execve" movw #PSL_USER,%sp@- | in user mode clrl %sp@- | stack adjust count and padding lea %sp@(-64),%sp | construct space for D0-D7/A0-A7 lea _C_LABEL(lwp0),%a0 | save pointer to frame movl %sp,%a0@(L_MD_REGS) | in lwp0.l_md.md_regs jra _C_LABEL(main) | main() /* * Trap/interrupt vector routines */ #include /* * Use common m68k bus error and address error handlers. */ #include /* * FP exceptions. */ ENTRY_NOPROFILE(fpfline) #if defined(M68040) cmpl #FPU_68040,_C_LABEL(fputype) | 68040 FPU? jne Lfp_unimp | no, skip FPSP cmpw #0x202c,%sp@(6) | format type 2? jne _C_LABEL(illinst) | no, not an FP emulation #ifdef FPSP jmp _ASM_LABEL(fpsp_unimp) | yes, go handle it #else clrl %sp@- | stack adjust count moveml #0xFFFF,%sp@- | save registers moveq #T_FPEMULD,%d0 | denote as FP emulation trap jra _ASM_LABEL(fault) | do it #endif Lfp_unimp: #endif /* M68040 */ jra _C_LABEL(illinst) ENTRY_NOPROFILE(fpunsupp) #if defined(M68040) cmpl #FPU_68040,_C_LABEL(fputype) | 68040 FPU? jne Lfp_unsupp | No, skip FPSP #ifdef FPSP jmp _ASM_LABEL(fpsp_unsupp) | yes, go handle it #else clrl %sp@- | stack adjust count moveml #0xFFFF,%sp@- | save registers moveq #T_FPEMULD,%d0 | denote as FP emulation trap jra _ASM_LABEL(fault) | do it #endif Lfp_unsupp: #endif /* M68040 */ jra _C_LABEL(illinst) /* * Handles all other FP coprocessor exceptions. * Note that since some FP exceptions generate mid-instruction frames * and may cause signal delivery, we need to test for stack adjustment * after the trap call. */ ENTRY_NOPROFILE(fpfault) clrl %sp@- | stack adjust count moveml #0xFFFF,%sp@- | save user registers movl %usp,%a0 | and save movl %a0,%sp@(FR_SP) | the user stack pointer clrl %sp@- | no VA arg movl _C_LABEL(curpcb),%a0 | current pcb lea %a0@(PCB_FPCTX),%a0 | address of FP savearea fsave %a0@ | save state #if defined(M68040) || defined(M68060) /* always null state frame on 68040, 68060 */ cmpl #FPU_68040,_C_LABEL(fputype) jge Lfptnull #endif tstb %a0@ | null state frame? jeq Lfptnull | yes, safe clrw %d0 | no, need to tweak BIU movb %a0@(1),%d0 | get frame size bset #3,%a0@(0,%d0:w) | set exc_pend bit of BIU Lfptnull: fmovem %fpsr,%sp@- | push fpsr as code argument frestore %a0@ | restore state movl #T_FPERR,%sp@- | push type arg jra _ASM_LABEL(faultstkadj) | call trap and deal with stack cleanup /* * Other exceptions only cause four and six word stack frame and require * no post-trap stack adjustment. */ ENTRY_NOPROFILE(badtrap) moveml #0xC0C0,%sp@- | save scratch regs movw %sp@(22),%sp@- | push exception vector info clrw %sp@- movl %sp@(22),%sp@- | and PC jbsr _C_LABEL(straytrap) | report addql #8,%sp | pop args moveml %sp@+,#0x0303 | restore regs jra _ASM_LABEL(rei) | all done ENTRY_NOPROFILE(trap0) clrl %sp@- | stack adjust count moveml #0xFFFF,%sp@- | save user registers movl %usp,%a0 | save the user SP movl %a0,%sp@(FR_SP) | in the savearea movl %d0,%sp@- | push syscall number jbsr _C_LABEL(syscall) | handle it addql #4,%sp | pop syscall arg tstl _C_LABEL(astpending) | AST pending? jne Lrei1 | Yup, go deal with it. movl %sp@(FR_SP),%a0 | grab and restore movl %a0,%usp | user SP moveml %sp@+,#0x7FFF | restore most registers addql #8,%sp | pop SP and stack adjust rte /* * Trap 12 is the entry point for the cachectl "syscall" (both HPUX & BSD) * cachectl(command, addr, length) * command in d0, addr in a1, length in d1 */ ENTRY_NOPROFILE(trap12) movl _C_LABEL(curlwp),%a0 movl %a0@(L_PROC),%sp@- | push current proc pointer movl %d1,%sp@- | push length movl %a1,%sp@- | push addr movl %d0,%sp@- | push command jbsr _C_LABEL(cachectl1) | do it lea %sp@(16),%sp | pop args jra _ASM_LABEL(rei) | all done /* * Trace (single-step) trap. Kernel-mode is special. * User mode traps are simply passed on to trap(). */ ENTRY_NOPROFILE(trace) clrl %sp@- | stack adjust count moveml #0xFFFF,%sp@- moveq #T_TRACE,%d0 | Check PSW and see what happen. | T=0 S=0 (should not happen) | T=1 S=0 trace trap from user mode | T=0 S=1 trace trap on a trap instruction | T=1 S=1 trace trap from system mode (kernel breakpoint) movw %sp@(FR_HW),%d1 | get PSW notw %d1 | XXX no support for T0 on 680[234]0 andw #PSL_TS,%d1 | from system mode (T=1, S=1)? jeq Lkbrkpt | yes, kernel breakpoint jra _ASM_LABEL(fault) | no, user-mode fault /* * Trap 15 is used for: * - GDB breakpoints (in user programs) * - KGDB breakpoints (in the kernel) * - trace traps for SUN binaries (not fully supported yet) * User mode traps are simply passed to trap(). */ ENTRY_NOPROFILE(trap15) clrl %sp@- | stack adjust count moveml #0xFFFF,%sp@- moveq #T_TRAP15,%d0 movw %sp@(FR_HW),%d1 | get PSW andw #PSL_S,%d1 | from system mode? jne Lkbrkpt | yes, kernel breakpoint jra _ASM_LABEL(fault) | no, user-mode fault Lkbrkpt: | Kernel-mode breakpoint or trace trap. (d0=trap_type) | Save the system sp rather than the user sp. movw #PSL_HIGHIPL,%sr | lock out interrupts lea %sp@(FR_SIZE),%a6 | Save stack pointer movl %a6,%sp@(FR_SP) | from before trap | If were are not on tmpstk switch to it. | (so debugger can change the stack pointer) movl %a6,%d1 cmpl #_ASM_LABEL(tmpstk),%d1 jls Lbrkpt2 | already on tmpstk | Copy frame to the temporary stack movl %sp,%a0 | a0=src lea _ASM_LABEL(tmpstk)-96,%a1 | a1=dst movl %a1,%sp | sp=new frame movql #FR_SIZE,%d1 Lbrkpt1: movl %a0@+,%a1@+ subql #4,%d1 jbgt Lbrkpt1 Lbrkpt2: | Call the trap handler for the kernel debugger. | Do not call trap() to do it, so that we can | set breakpoints in trap() if we want. We know | the trap type is either T_TRACE or T_BREAKPOINT. | If we have both DDB and KGDB, let KGDB see it first, | because KGDB will just return 0 if not connected. | Save args in d2, a2 movl %d0,%d2 | trap type movl %sp,%a2 | frame ptr #ifdef KGDB | Let KGDB handle it (if connected) movl %a2,%sp@- | push frame ptr movl %d2,%sp@- | push trap type jbsr _C_LABEL(kgdb_trap) | handle the trap addql #8,%sp | pop args cmpl #0,%d0 | did kgdb handle it? jne Lbrkpt3 | yes, done #endif #ifdef DDB | Let DDB handle it movl %a2,%sp@- | push frame ptr movl %d2,%sp@- | push trap type jbsr _C_LABEL(kdb_trap) | handle the trap addql #8,%sp | pop args #endif /* Sun 3 drops into PROM here. */ Lbrkpt3: | The stack pointer may have been modified, or | data below it modified (by kgdb push call), | so push the hardware frame at the current sp | before restoring registers and returning. movl %sp@(FR_SP),%a0 | modified sp lea %sp@(FR_SIZE),%a1 | end of our frame movl %a1@-,%a0@- | copy 2 longs with movl %a1@-,%a0@- | ... predecrement movl %a0,%sp@(FR_SP) | sp = h/w frame moveml %sp@+,#0x7FFF | restore all but sp movl %sp@,%sp | ... and sp rte | all done /* * Interrupt handlers. * * For auto-vectored interrupts, the CPU provides the * vector 0x18+level. * * intrhand_autovec is the entry point for auto-vectored * interrupts. */ ENTRY_NOPROFILE(intrhand_autovec) addql #1,_C_LABEL(intr_depth) INTERRUPT_SAVEREG jbsr _C_LABEL(intr_dispatch) | call dispatcher INTERRUPT_RESTOREREG subql #1,_C_LABEL(intr_depth) /* FALLTHROUGH to rei */ /* * Emulation of VAX REI instruction. * * This code deals with checking for and servicing ASTs * (profiling, scheduling). * After identifying that we need an AST we drop the IPL to allow device * interrupts. * * This code is complicated by the fact that sendsig may have been called * necessitating a stack cleanup. */ ASENTRY_NOPROFILE(rei) tstl _C_LABEL(astpending) | AST pending? jeq Ldorte | Nope. Just return. btst #5,%sp@ | Returning to kernel mode? jne Ldorte | Yup. Can't do ASTs movw #PSL_LOWIPL,%sr | lower SPL clrl %sp@- | stack adjust moveml #0xFFFF,%sp@- | save all registers movl %usp,%a1 | including movl %a1,%sp@(FR_SP) | the users SP Lrei1: clrl %sp@- | VA == none clrl %sp@- | code == none movl #T_ASTFLT,%sp@- | type == async system trap pea %sp@(12) | fp == address of trap frame jbsr _C_LABEL(trap) | go handle it lea %sp@(16),%sp | pop value args movl %sp@(FR_SP),%a0 | restore user SP movl %a0,%usp | from save area movw %sp@(FR_ADJ),%d0 | need to adjust stack? jne Laststkadj | yes, go to it moveml %sp@+,#0x7FFF | no, restore most user regs addql #8,%sp | toss SP and stack adjust Ldorte: rte | and do real RTE Laststkadj: lea %sp@(FR_HW),%a1 | pointer to HW frame addql #8,%a1 | source pointer movl %a1,%a0 | source addw %d0,%a0 | + hole size = dest pointer movl %a1@-,%a0@- | copy movl %a1@-,%a0@- | 8 bytes movl %a0,%sp@(FR_SP) | new SSP moveml %sp@+,#0x7FFF | restore user registers movl %sp@,%sp | and our SP rte | and do real RTE /* * Primitives */ /* * Use common m68k process/lwp switch and context save subroutines. */ #define FPCOPROC /* XXX: Temp. Reqd. */ #include #if defined(M68040) || defined(M68060) ENTRY(suline) movl %sp@(4),%a0 | address to write movl _C_LABEL(curpcb),%a1 | current pcb movl #Lslerr,%a1@(PCB_ONFAULT) | where to return to on a fault movl %sp@(8),%a1 | address of line movl %a1@+,%d0 | get lword movsl %d0,%a0@+ | put lword nop | sync movl %a1@+,%d0 | get lword movsl %d0,%a0@+ | put lword nop | sync movl %a1@+,%d0 | get lword movsl %d0,%a0@+ | put lword nop | sync movl %a1@+,%d0 | get lword movsl %d0,%a0@+ | put lword nop | sync moveq #0,%d0 | indicate no fault jra Lsldone Lslerr: moveq #-1,%d0 Lsldone: movl _C_LABEL(curpcb),%a1 | current pcb clrl %a1@(PCB_ONFAULT) | clear fault address rts #endif ENTRY(ecacheon) rts ENTRY(ecacheoff) rts /* * Misc. global variables. */ .data GLOBAL(mmutype) .long MMU_68040 | default to MMU_68040 GLOBAL(cputype) .long CPU_68040 | default to CPU_68040 GLOBAL(fputype) .long FPU_68040 | default to FPU_68040