;---; RESET ;-------------------------------------------------------------------- * * **** RESET ROUTINE **** * * Author Daniel Weber * Version 1.13 * Last Revision 14.02.93 * Identifier rtr_defined * Prefix rtr_ (Reset Routine) * ¯ ¯ ¯ * Functions ColdReboot() * ;------------------------------------------------------------------------------ * * Amiga Software Reboot * * By Daniel Weber in 1990 * * * Based on the offical reboot code published by Commodore * * * - The entire risk as to the use of this - * - information is assumed by the user - * * For more information read "The Official Way to Software Reboot an * Amiga" from the July/August 1989 issue of Amiga Mail, Exec, * page III-9. * * * The ColdReboot() function listed below should be used whenever an * application needs to reboot the Amiga. * This code represents the *best* available general purpose reset. * * * TECHNICAL DESCRIPTION: * The code below turns an installed MMU off, precalculates a jump * address, executes a RESET instruction, then relies on CPU * prefetch to execute the jump. The precalculated jump is * constructed to enter the system ROM at the location of a second * RESET instruction. * ;------------------------------------------------------------------------------ * * NAME * ColdReboot * * SYNOPSIS * ColdReboot() * * void ColdReboot(void); * * FUNCTION * Reboot the machine. Turn an installed MMU off, all external * memory and peripherals will be RESET, and the machine will * start its power up diagnostics. * * NOTE * Rebooting an Amiga in software is very tricky. Differing * memory configurations and processor cards require careful * treatment. This code represents the *best* available * general purpose reset. * * The MagicResetCode must be used exactly as specified here. * The code *must* be longword aligned. Failure to duplicate * the code *exactly* may result in improper operation under * certain system configurations. * * RESULT * This function never returns. * ;------------------------------------------------------------------------------ ;------------------ IFND rtr_defined rtr_defined =1 ;------------------ rtr_oldbase equ __BASE base rtr_base rtr_base: ; ;-------------------------------------------------------------------- ; opt sto ;only for the ProAsm assembler opt o+,ow-,q+ mc68030 ;use the MC68030 for the MMU coding ; ;-------------------------------------------------------------------- ; rtr_MAGIC_ROMEND EQU $01000000 ;End of Kickstart ROM rtr_MAGIC_SIZEOFFSET EQU -$14 ;Offset from end of ROM to Kickstart size rtr_V36_EXEC EQU 36 ;Exec with the ColdReboot() function rtr_TEMP_ColdReboot EQU -726 ;Offset of the V36 ColdReboot function ; ;-------------------------------------------------------------------- ; ColdReboot: bsr.s rtr_CacheOff bsr rtr_killMMU move.l 4.w,a6 cmp.w #rtr_V36_EXEC,20(a6) blt.s rtr_old_exec jmp rtr_TEMP_ColdReboot(a6) ;Let Exec do it... ; ; NOTE: Control flow never returns to here ; ;--- manually reset the Amiga --------------------------------------- ; rtr_old_exec: lea rtr_GoAway(pc),a5 ;address of code to execute jsr -30(a6) ;trap to code at (a5) ; ; ; NOTE: Control flow never returns to here ; ;--- MagicResetCode ---------------- PLEASE DO NOT CHANGE ----------- ; CNOP 0,4 ;IMPORTANT! Longword align! rtr_GoAway: lea rtr_MAGIC_ROMEND,a0 ;(end of ROM) sub.l rtr_MAGIC_SIZEOFFSET(a0),a0 ;(end of ROM)-(ROM size)=PC move.l 4(a0),a0 ;Get Initial Program Counter subq.l #2,a0 ;now points to second RESET RESET ;first RESET instruction jmp (a0) ;CPU prefetch executes this ; ; ; NOTE: the RESET an JMP instruction must share a longword!!! ; ; ;--- turn caches off... ; ; rtr_CacheOff: move.l 4.w,a6 btst #1,AttnFlags+1(a6) ;AFB_68020 beq.s 4$ ;at least a 68020 expected cmp.w #rtr_V36_EXEC,20(a6) blt.s 3$ moveq #0,d0 move.l #CACRF_ClearI|CACRF_ClearD|CACRF_EnableI|CACRF_EnableD|CACRF_IBE|CACRF_DBE,d1 jsr _LVOCacheControl(a6) ;this function clears all caches rts 3$: lea 5$(pc),a5 jsr _LVOSupervisor(a6) 4$: rts 5$: move.l #CACRF_ClearI|CACRF_ClearD|CACRF_WriteAllocate,d0 movec d0,cacr rte ; ;--- kill an installed MMU --------- DO NOT CHANGE ANYTHING ! ------- ; ; rtr_killMMU: move.l 4.w,a6 sub.l a1,a1 ;look first for a MMU jsr -294(a6) ;get ThisTask move.l d0,a1 move.l 50(a1),a2 ;save old TaskException pea rtr_taskexception(pc) move.l (a7)+,50(a1) ;put own Exceptionhandler in moveq #-1,d0 ;set flag "MMU FOUND" subq.l #4,a7 nop pmove tc,(a7) nop nop addq.l #4,a7 tst.l d0 bne.s 1$ nop mc68040 movec tc,d1 ;68040 instruction mc68030 nop nop neg.l d0 ;-1 => +1 (mc68040) 1$: move.l a2,50(a1) ;restore old Exceptionhandler rtr_killMMU_now: tst.l d0 ;MMU found??? beq.s \no_MMU_around lea rtr_kill_it(pc),a5 jsr -30(a6) ;trap on code at (a5) \no_MMU_around: rts ;-------------------------------------------------------------------- rtr_kill_it: ;kill MMU tst.w d0 bpl.s 1$ clr.l -(a7) pmove (a7),tc ;turn 68030/68851 mmu off addq.l #4,a7 rte ;back to 'no_MMU_around' mc68040 1$: movec tc,d0 ;turn 68040 mmu off bclr #15,d0 movec d0,tc rte mc68030 ;-------------------------------------------------------------------- rtr_taskexception: moveq #0,d0 ;'NO MMU FOUND' move.l (a7)+,d1 ;load trapnumber in d1 cmp.w #4,d1 ;'illegal' (no movec) beq.s 1$ cmp.w #11,d1 ;'line-f' (no pmove) beq.s 1$ moveq #-1,d0 ;'MMU FOUND' 1$: addq.l #4,2(a7) ;adjust PC *after* pmove instruction rte ;-------------------------------------------------------------------- ;------------------ base rtr_oldbase ;------------------ opt rcl ;only for the ProAsm assembler ;------------------ ENDIF ;-------------------------------------------------------------------- END