409 lines
14 KiB
ArmAsm
409 lines
14 KiB
ArmAsm
*******************************************************
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* Program/data relocation routine is driven by a table
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* describing program, vectors, and data segments. The
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* table has the general format:
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* (1)command: 0= zero destinaton range.
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* 1= move data to from src to dst.
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* 2= high address ref tbl, relocate & move.
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* 3= lo-hi addr ref tbl, relocate & move.
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* 4= program, relocate & move.
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* >4= end of table.
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* (2)dest addr: address of where segment is to be moved.
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* (2)byte count: length of segment.
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* (2)source addr: start address segment to be operated on,
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* n/a if type=0, code does not have to be
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* assembled at this address.
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* (1)segments: number of address ranges to be tested
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* and altered, n/a if type=0 or 1.
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* limit and offset lists should each
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* contain segments+1 (s) bytes.
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* (s)limitlow: list of low page addresses to be tested.
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* (s)limithigh: list of high page addresses to be tested.
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* (s)offset: list of amounts to be added if
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* low & high limits have been met.
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*
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* on entry: (X)=table address low, (Y)=table address high
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* on exit: carry clear if no error; else carry set,
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* (X)=addrLo, (Y)=addrHi of error causing source.
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* (A)=0 if input table error, =$ff if illegal opcode.
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*******************************************************
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Reloc STX relocTbl
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STY relocTbl+1 ;Save address of control table
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RelLoop LDA (relocTbl) ;Get relocation command
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CMP #$05 ;If 5 or greater then done...
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BCS RelocEnd ;Branch if done
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TAX
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LDY #$01 ;Move destination address to
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LDA (relocTbl),Y ; zero page for indirect access
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STA dst
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INY
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LDA (relocTbl),Y
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STA dst+1
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INY
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LDA (relocTbl),Y ;Also the length (byte count)
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STA cnt ; of the destination area
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INY
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LDA (relocTbl),Y
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STA cnt+1
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BMI RelocErr ;Branch if >=32K
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TXA ;Request to zero out destination?
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BEQ Zero ;Branch if it is
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INY
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LDA (relocTbl),Y ;Now get the source address
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STA src
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STA code ;src is used for the move, 'code' is
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INY ; used for relocation
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CLC ;Add length to get final address
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ADC cnt
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STA endCode
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LDA (relocTbl),Y
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STA src+1
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STA code+1
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ADC cnt+1
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STA endCode+1
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DEX ;Now that set-up is done, test for 'move'
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BEQ MovEm ;Branch if move only (no relocation)
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STX wSize ;Save element size (1,2,3)
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INY
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LDA (relocTbl),Y ;Now get the number of ranges
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STA segCnt ; that are valid relocation target addresses
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TAX ;Separate serial range groups into tables
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RLimLo INY ;Transfer low limits to 'limlo' table
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LDA (relocTbl),Y
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STA LimLo,X
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DEX
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BPL RLimLo
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LDX segCnt
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RLimHi INY
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LDA (relocTbl),Y ;Transfer high limits to 'limhi' table
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STA LimHi,X
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DEX
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BPL RLimHi
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LDX segCnt
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Rofset INY
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LDA (relocTbl),Y ;Transfer offsets to 'ofset' table
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STA Ofset,X
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DEX
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BPL Rofset
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JSR AdjTbl ;Adjust 'relocTbl' to point at next spec
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LDX wSize ;Test for machine code relocation
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CPX #$03
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BEQ RelCode ;Branch if program relocation
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* 2/3 - Relocate addresses
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JSR RelAdr ;Otherwise, relocate addresses in
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RelocEnd1 JSR Move ; one or two byte tables, then move to destination
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BRA RelLoop ;Do next table entry...
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RelocEnd CLC
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RTS
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RelocErr JMP TblErr
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*-------------------------------------------------
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* 4 - Relocate instructions
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RelCode JSR RelProg ;Go relocate machine code references
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BRA RelocEnd1
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* 0 - Zero block
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Zero JSR AdjTbl ;Adjust 'relocTbl' pointer to next entry
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LDA #$00 ;Fill destination range with zeros
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LDY cnt+1 ;Is it at least a page?
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BEQ ZPart ;Branch if less than 256 bytes
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TAY
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:ZeroLoop STA (dst),Y
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INY
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BNE :ZeroLoop
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INC dst+1 ;bump to next page
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DEC cnt+1
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BNE :ZeroLoop
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ZPart LDY cnt ;any bytes left to zero?
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BEQ Zeroed ;branch if not
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TAY
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:loop STA (dst),Y
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INY
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CPY cnt
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BCC :loop
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Zeroed JMP RelLoop
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* 1 - Copy block
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MovEm JSR AdjTbl
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BRA RelocEnd1
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*-------------------------------------------------
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* Advance table ptr
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AdjTbl TYA ;Add previous table length to 'relocTbl'
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SEC ; to get position of next entry in table
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ADC relocTbl
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STA relocTbl
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BCC :Rtn
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INC relocTbl+1
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:Rtn RTS
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*-------------------------------------------------
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Move LDA src+1 ;Determine if move is up, down
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CMP dst+1 ; or not at all
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BCC MovUp ;Branch if definitely up...
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BNE MovDown ;Branch if definitely down...
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LDA src
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CMP dst
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BCC MovUp ;Branch if definitely up...
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BNE MovDown ;Branch if definitely down...
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RTS ;Otherwise, don't move nuting
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*-------------------------------------------------
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* src addr < dest addr
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MovUp LDY cnt+1 ;Calc highest page of move up
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TYA
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CLC
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ADC src+1
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STA src+1 ; & adjust src & dst accordingly
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TYA
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CLC
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ADC dst+1
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STA dst+1
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LDY cnt ;Move partial page first
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BEQ :1 ;Branch if no partial pages
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:MovLoop DEY
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LDA (src),Y
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STA (dst),Y
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TYA ;End of page transfer?
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BNE :MovLoop ;No
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:1 DEC dst+1
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DEC src+1
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DEC cnt+1 ;Done with all pages?
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BPL :MovLoop ;Branch if not
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RTS
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*-------------------------------------------------
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* src addr > dest addr
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MovDown LDY #$00
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LDA cnt+1 ;Partial page move only?
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BEQ :1 ;Branch if less than a page to be moved
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:MovLoop1 LDA (src),Y
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STA (dst),Y
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INY
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BNE :MovLoop1
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INC dst+1 ;Bump addresses
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INC src+1
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DEC cnt+1 ;More pages?
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BNE :MovLoop1 ;Branch if more pages
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:1 LDA cnt ;Move partial page
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BEQ :Rtn ;Branch if no more to move
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:MovLoop2 LDA (src),Y
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STA (dst),Y
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INY
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CPY cnt
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BNE :MovLoop2
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:Rtn RTS ;All done...
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*-------------------------------------------------
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* Address/page relocate
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RelAdr LDY wSize ;Determine 1 or 2 byte reference
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DEY
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LDA (code),Y
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JSR AdjAdr ;Relocate reference
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LDA wSize ;Update and test 'code' pointer
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JSR AdjCode
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BCC RelAdr ;Branch if more to do
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RTS
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*-------------------------------------------------
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* Instructions relocate
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RelProg LDY #$00 ;Fetch next opcode
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LDA (code),Y
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JSR GetOpLen ;Determine if it's a 3-byte instruction
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BEQ RPerr ;Branch if not an opcode
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CMP #$03
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BNE :1
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LDY #$02
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JSR AdjAdr ;Relocate address
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LDA #$03
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:1 JSR AdjCode ;Update and test 'code' for done
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BCC RelProg ;Loop if more to do
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RTS
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*-------------------------------------------------
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* Error handling...
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RPerr PLA ;Return bad code address
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PLA ;First un-do stack
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LDX code
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LDY code+1
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LDA #$FF ;Indicate bad opcode
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SEC ;Indicate error
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RTS
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*-------------------------------------------------
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* Error return
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TblErr LDX relocTbl ;Return table address error
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LDY relocTbl+1
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LDA #$00 ;Indicate input table error
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SEC
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RTS
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*-------------------------------------------------
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* Relocate absolute addr
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AdjAdr LDA (code),Y ;Get page address
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LDX segCnt ; and test against limits
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:AdjLoop CMP LimLo,X ;Is it >= low?
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BCC :Next ;Branch if not
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CMP LimHi,X ;Is it =< highest page limit
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BCC :1 ;Branch if it is
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BEQ :1
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:Next DEX ;Try next limit set
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BPL :AdjLoop
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RTS ;Teturn without adjustment
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:1 CLC ;Add offset to form relocated
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ADC Ofset,X ; page address
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STA (code),Y ; & replace old address with result
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RTS
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*-------------------------------------------------
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* Bump ptr to next addr
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AdjCode CLC ;Update 'code' pointer
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ADC code
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LDY code+1
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BCC :1 ;Branch if not page cross
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INY ;Update high order address too
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:1 CPY endCode+1 ;Has all code/data been processed?
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BCC :2 ;Branch if definitely not
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CMP endCode ;If carry results set, end of code
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:2 STA code
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STY code+1 ;Save updated values
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RTS ;Return result (carry set=done)
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*-------------------------------------------------
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* Compute instruction len
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GetOpLen PHA ;Form index to table and which 2-bit group
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AND #$03 ;Low 2 bits specify group
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TAY
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PLA
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LSR ;Upper 6 bits specify byte in table
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LSR
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TAX
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LDA OpCodeLen,X
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NxtGroup DEY ;Is opcode length in lowest 2 bits of A-reg?
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BMI RtnLen ;Branch if it is
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LSR
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LSR ;Shift to next group
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BNE NxtGroup ;If len=0 then error...
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RtnLen AND #$03 ;Strip other garbage
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RTS ;If z-flag true, then error!!!
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*-------------------------------------------------
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* The following table contains the length of each
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* machine instruction (in two-bit groups).
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OpCodeLen HEX 0928193C
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HEX 0A280D3C
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HEX 0B2A193F
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HEX 0A280D3C
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HEX 0928193F
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HEX 0A280D3C
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HEX 0928193F
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HEX 0A280D3C
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HEX 082A113F
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HEX 0A2A1D0C
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HEX 2A2A193F
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HEX 0A2A1D3F
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HEX 0A2A193F
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HEX 0A280D3C
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HEX 0A2A193F
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HEX 0A280D3C
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*-------------------------------------------------
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* Relocation Data
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wSize DB $00
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segCnt DB $00
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LimLo HEX 0000000000000000;Start of range pages
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LimHi HEX 0000000000000000;End of pages+1
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Ofset HEX 0000000000000000;Additive factors
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*-------------------------------------------------
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* Install an exit code
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* The locations GSOS($E100A8) & GSOS2 ($E100B0)
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* are patched if the boot OS is P8
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GSPatches PHP
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SEI
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CLC
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XCE
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REP #$30
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PHB
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PHA
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PHA ;long result
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PushLong #ZZSize ;size 16 bytes
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PushWord #$3101 ;userID
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PushWord #attrLocked+attrNoCross+attrNoSpec
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PHA
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PHA
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_NewHandle
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LDA $01,S ;Let handle remain on stack
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TAX ; since we need it later but
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LDA $03,S ; move a copy to (Y,X)
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TAY
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PushLong #ExitPatch ; srcPtr
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PHY
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PHX ;destHndl
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PushLong #ZZSize ;# of bytes to be copied
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_PtrToHand
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PLX ;Put 24 bits of the 32-bit
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PLB ; handle that was left on stack
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LDA |$0001,X ; deref
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TAY ;mid & hi-byte of 24-bit ptr
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LDA |$0000,X ; low 16-bit of 24-bit ptr
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AND #$00FF ; Mask off mid byte
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XBA ;Lobyte of ptr to Hi-byte in ACC
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ORA #$005C ;Add in JMPL inst
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STAL GSOS2 ;$5C xx
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CLC
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ADC #$000B ; ADC[]
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STAL GSOS
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TYA ; mid & hi byte of 24-bit ptr
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STAL GSOS2+2 ;yy zz
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ADC #$0000
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STAL GSOS+2
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PLB ;Discard the rest of the handle
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PLB
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SEC
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XCE
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PLP
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RTS
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*-------------------------------------------------
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* Remove 3 words & adjust stack
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* to return to caller
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MX %00
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ExitPatch LDA $01,S ;RTL-1 addr
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STA $07,S
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LDA $02,S
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STA $07+1,S
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PLA
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PLA
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PLA
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LDA #$00FF
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SEC
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RTL
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ZZSize EQU *-ExitPatch
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DS $23,0 |