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Assembly Source File | 1993-10-25 | 17.1 KB | 899 lines

* safram.asm Roy Lipscomb * Version 1.0 Aug 1, 1982 * * Creates a "safe" partition below BDOS. Modules residing * in the partition are safe from destruction until the * the next system reset. * * Copyright 1982 by Roy Lipscomb, Logic Associates, Chicago * * Original distributor: HP/RCPM, (312) 955-4493 * * ******************************************************************** * * Description of this program is contained in SAFRAM.DOC and * in SAFRAM.H. * * Before attempting to assemble this source, please read the * ASSEMBLING section in SAFRAM.DOC. * ********************************************************* * service/loader routines * ********************************************************* if copy1 ;service routines org 100h jmp begin no equ 0 yes equ 1 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; customizing variables ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; boot equ 0 ;lowest address within CP/M notify equ yes ;at each ^C, notify of secure addr hotboot equ 0 ;set to 0 to deactivate. ;hotboot gives displacement from start ; of bios to first instruction after ; code that loads CCP/BDOS/BIOS. ; See document SAFRAM.H for information. pagebnd equ no ;to force all secure addresses ;to page boundary, change to "yes" ;nothing below this point needs to be customized. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; bell equ 7 coutdsp equ 12-3 ;displacement of charout from wboot bdosjmp equ boot+5 pstr equ 9 deffcb equ boot+5ch tbuff equ boot+80h tab equ 9 cr equ 13 lf equ 10 blank equ ' ' pageopt equ (not pagebnd)/100h ;if pagebnd = no, pageopt = 0ffh secaddr dw 0 ;highest available RAM excluding CCP loadpnt dw 0 modbase dw 0 ;starting point of module ;(different from loadpnt if old module) ;values used in setting traps biosdsp dw 0 biosav dw 0 trapent dw 0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;values used in manipulating the ccp doslen1 equ 0d00h ;length of cpm 1.x bdos doslen2 equ 0e00h ;length of cpm 2.x bdos ccplen equ 800h ;length of ccp ccpclen equ 7 ;ccp command-length byte ccpcchr equ 88h ;ccp current-char displacement ccp dw 0 ;ccp entry point curdrv equ 4 ;current drive in pg zero ccpstrt dw 0 ;pointer to first char in ccp buff ;messages eom equ '$' baddr db cr,lf db bell db 'Abort: Valid address range at present is ' badad1 db '....H through ' badad2 db '....H.' db cr,lf db '$' ccpmess db 'Abort: unable to locate CCP' db bell,cr,lf,cr,lf,eom helpmes db cr,lf db ' SAFRAM' db ' Copyright 1982 by Roy Lipscomb, Logic Associates' db cr,lf db ' Version 1.0 Aug, 1982' db cr,lf db cr,lf db ' Assigns safe partition (removed only by system' db ' reset) below BDOS.' db cr,lf db ' (Multiple executions of SAFRAM are permitted).' db cr,lf db cr,lf db ' [] To secure the CCP or the boot+6 address, ' db 'type "SAFRAM".' db cr,lf db ' [] To secure a lower address, type "SAFRAM xxxx",' db ' where' db cr,lf db ' "xxxx" is address in hex.' db cr,lf db cr,lf db ' ',eom crlf db cr,lf db eom ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; mainline ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; begin call signon ;print signon message call getbase ;compute load address: just below CCP cz ccperr ;ccp not found jz exit ;test for explicit address on command line. Abort if bad. call expladr jnz exit ;quit if error ;if already loaded and active, don't load again (just update it) call tstact cz active cnz instal ;if ddt executing, do restart 7; else return to cpm exit lxi h,0 dad sp ;if stack pointer <= 100, mov a,h ; then ddt active cpi 2 rnc ;stack pointer >1ff, so must be cpm rst 7 ;ddt active; do restart 7 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; compute load address ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;if ccp not found, return with zero set ;first try to find ccp: standard method getbase lhld boot+6 shld secaddr ;secure-address if ccp already ; secured (default) lxi d,0 call tstccp ;add de and hl for candidate ccpbase jz ccpnosc ;ccp found, not secured ;second try: via cbios entry point of cpm 2.x lhld boot+1 lxi d,-doslen2 call tstccp ;add de and hl for candidate ccpbase jz ccpsec ;ccp found, secured ;last try: via cbios entry point of cpm 1.x lhld boot+1 lxi d,-doslen1 call tstccp ;add de and hl for candidate ccpbase jz ccpsec ;ccp found, secured ;ccp not found xra a ret ;set zero flag ("not found") ;ccp secured/not-secured ccpnosc lhld ccp ;(really contains bdos addr here) shld secaddr ;set to secure ccp ccpsec ori 1 ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;test for explicit address on command line. Abort if error ;if no error, return with z flag = yes ;get parm length and address expladr lxi d,tbuff ;get parm length ldax d mov b,a ;save parm length byte inr b ;skip leading blanks, exit if nothing left expl4 dcr b jz expl9 inx d ldax d call blnktab ;test for blank or tab jz expl4 ;digest the parm lxi h,0 ;initialize hex value expl6 call asc2hex ;build hex value in hl jnz expl8 ;exit if error dcr b jz expl7 inx d ldax d call blnktab ;test for blank or tab jnz expl6 ;value digested: verify it's acceptable expl7 xchg ;save in de lxi h,progend+2 call neghl dad d jnc expl8 ;error if below end of this prog... lhld secaddr inx h call neghl dad d jc expl8 ; ...or if higher than available top ;value ok: substitute it for implicit address xchg shld secaddr xra a ;set z = "no error" jmp expl9 ;error exit: display acceptable addr range, then exit. expl8 lxi h,progend+3 call hex2asc ;put value in de and hl lxi h,badad1 call put2bad lhld secaddr call hex2asc lxi h,badad2 call put2bad lxi d,baddr mvi c,pstr call bdosjmp ori 1 ;set z = "error" expl9 ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;test for blank or tab in a; if yes, return z = yes blnktab cpi blank rz cpi tab ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;put address into error message put2bad mov m,b inx h mov m,c inx h mov m,d inx h mov m,e ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;convert ascii characters into hex (using hl) asc2hex sui '0' rc ;exit if invalid char cpi 10 jc asc2b sui 7 cpi 16 jnc asc2x asc2b dad h dad h dad h dad h add l mov l,a xra a ;set z = "no error" ret ;error exit asc2x ori 1 ;set z = "error" ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;convert hex value to ascii hex2asc call hex2b mov b,d mov c,e hex2b call hex2c mov d,a call hex2c mov e,a ret hex2c mov a,h dad h dad h dad h dad h rar rar rar rar ani 0fh adi '0' cpi '9'+1 rc adi 7 ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;convert hl to its negative neghl push psw mov a,h cma mov h,a mov a,l cma mov l,a inx h pop psw ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;test if this location has ccp ;compute tentative ccpbase tstccp mvi l,0 dad d ;compute tentative bdos entry point lxi d,-ccplen dad d ;tentative bdos entry minus ccp length shld ccp ; ...gives tentative ccp entry ;test for the two leading jumps in the ccp mvi a,jmp lxi b,3 cmp m rnz dad b cmp m rnz ;test for standard "maximum buffer length" value dad b mov a,m cpi 7fh ;standard ccp maxbuff len jz tstcc4 cpi 50h ;standard zcp maxbuff len rnz ;test for "buffer length" < "maximum buffer length" tstcc4 inx h cmp m rc ;give up if bufflen > maxbufflen xra a ;looks ok ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; test if module already active ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;check address in bios table for wboot tstact lhld boot+1 inx h mov e,m inx h mov d,m xchg shld modbase ;save it ;test if "secure" message present where expected lxi d,wb2mess ;get adjustment for message dad d ;compare to unmoved module message lxi d,message+module1 mvi b,testlen tstmess ldax d cmp m jnz failtst inx h inx d dcr b jnz tstmess ;active already xra a ret failtst ori 1 ;set flag ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; module already active: process only stub ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;determine where to install bypass active lhld secaddr lxi d,-3 dad d mvi a,pageopt ana l mov l,a shld loadpnt ;determine old module's start lhld modbase lxi d,-beforwb dad d shld modbase ;secure, then update message and savearea call doprot ;set for display of current secured address lhld modbase lxi d,bootflg dad d mvi m,on ;set flag to "on" ;set to bypass "not active" module xra a ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; module not active: load from scratch ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;if hotboot option requested, set it now instal call sethot ;compute load point lhld secaddr lxi d,-length dad d mvi a,pageopt ana l mov l,a shld loadpnt shld modbase ;modbase = new module entry ;move it call chgaddr ;convert to true addresses call movemod ;move module to load address call traps ;install traps call doprot ;do secure, and update message ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;overlay warmboot jmptable entry with hotboot, if hotboot > bdos. sethot lxi b,hotboot mov a,b ora c jz noacex ;hotboot option not in effect, so exit. lhld boot+1 ;put warmstart jmptab entry into hl mov d,h mov e,l ; point de to warmboot jmp addr inx d dcx b ;normalize bc for warmstart, not cold dcx b dcx b dad b ;compute hl = hotboot jump address mov a,l ;substitute hot for warm boot address stax d inx d mov a,h stax d noacex ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; convert module1 to true addresses ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; change pseudo addresses to true addresses chgaddr lxi b,length lxi d,module1 lxi h,module2 truloop ldax d cmp m cnz convert inx h inx d dcx b mov a,b ora c jnz truloop ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; convert displacement into address ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; convert push b ;length of module not yet processed push h ;module2 character position ; get displacement from instruction, put into bc. ldax d mov b,a dcx d ldax d mov c,a lxi h,-module1 ;normalize displacement to zero dad b push h pop b lhld loadpnt ;add load point for true addr dad b ; move true address to instruction mov a,l stax d inx d mov a,h stax d pop h pop b ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; move module into place ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; movemod lhld loadpnt xchg ;de=destination lxi h,module1 ;hl=source lxi b,length call move ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; install security, describe in message ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;move the new secured address to de, then store wherever needed ; secure the module doprot lhld 6 xchg lhld loadpnt shld 6 ;install bypass at base of secured RAM push h ;save new secured address mvi m,jmp inx h mov m,e inx h mov m,d pop d ;restore new secured address ;store new secured address in module lhld modbase lxi b,savbase dad b mov m,e inx h mov m,d ;convert hex address at location 6 to ascii, put in message lhld modbase ;address message lxi b,messadr dad b ;pointer to message into hl ;output hi and lo bytes of address to message call hilo hilo mov a,d mov d,e ;get next byte push psw rar rar rar rar call hexbyte pop psw hexbyte ani 0fh adi '0' cpi '9'+1 jc movhex adi 7 movhex mov m,a inx h ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; set all traps ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;set trap for wboot traps lxi h,toboot+1 shld biosav lxi h,beforwb shld trapent lxi h,0 shld biosdsp call settrap ;set trap for conout lxi h,jmpcout+1 shld biosav lxi h,pentry shld trapent lxi h,coutdsp shld biosdsp call settrap ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; set a trap ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; settrap lhld modbase ;get address of moved module push h pop b ;save in bc lhld biosdsp ;get displace for bios jmptable into de push h pop d ;get contents of bios jumptable entry lhld boot+1 dad d ;address bios jumptable entry inx h push h ;...save pointer to table entry mov e,m ;...and get contents inx h mov d,m ;store bios entry into trap savearea lhld biosav ;save bios contents into trap mod dad b mov m,e inx h mov m,d ;set bios entry to trap entry lhld trapent ;get addr of appropriate trap into de dad b xchg pop h ;store trap addr in bios jmptab mov m,e inx h mov m,d ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; print messages ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; signon lxi d,helpmes jmp domess ccperr lxi d,ccpmess domess mvi c,pstr call bdosjmp xra a ;set zero flag (for ccperr return) ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; move block of data ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;source in hl, destination in de, length in bc. move mov a,b ora c rz mov a,m stax d inx d inx h dcx b jmp move ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; end of service routines ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; endif ********************************************************* ********************************************************* * beginning of movable module * ********************************************************* ********************************************************* org ($+0ffh)/100h*100h ;must be page boundary adjust set $ if copy1 module1 equ $ endif if not copy1 module2 equ $ endif ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; address equ 0ffffh ;various address to fill at runtime on equ 0 ;do resecure off equ 0ffh pflag equ on ;harden security as soon as loaded pbase equ $-adjust jmp address ;security base: "address" set at run ;time to jump to previous pbase notiflg equ $-adjust db notify ;yes/no for message at each ^C ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;maintrap: perform setup if wboot (or trap just loaded) pentry equ $-adjust bootflg equ pentry+1 mvi a,pflag ;"on" for wboot cpi on ;test for "on" cz afterwb+adjust jmpcout equ $-adjust jmp address ;from bios conout jmptable entry ;("address" set at runtime) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;pre-wboot action: set flag beforwb equ $-adjust mvi a,on sta bootflg+adjust toboot equ $-adjust jmp address ;on to wboot (address set at runtime) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;post-wboot action: reset flag, restore security, rearm boot trap afterwb equ $-adjust mvi a,off sta bootflg+adjust ;turn off flag savbase equ $-adjust+1 lxi h,address ;restore secured address to 5h shld 6 ;("address" filled at runtime) ;if display option set, notify that security still in effect lda notiflg+adjust cpi yes rnz push b lxi d,message+adjust ;notify of current pbase display equ $-adjust ldax d inx d cpi eom jz dispend+adjust mov c,a push d call jmpcout+adjust pop d jmp display+adjust dispend equ $-adjust pop b ret ;don't remove the message below; used to test if module already present message equ $-adjust ;(number of blanks below is arbitrary) db ' ' db '(Safram at ' messadr equ $-adjust db '....)',cr,lf,eom wb2mess equ message-beforwb ;distance from wboot trap testlen equ messadr-message ********************************************************* * end of relocatable routines * ********************************************************* ;get length of relocatable routines length equ $-adjust ;flip the copy1/copy2 toggle copy1 set not copy1 ;assemble address of end of this program if copy1 progend equ $ endif ;link a second copy, if this was the first copy if not copy1 link safram endif ram if copy1 p