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112 lines
2.9 KiB

;___ROM0_______________________________________________________________________________________________________________
;
; HARDWARE BOOTSTRAP
;
; TEMPORARY HARDWARE BOOTSTRAP TO USE UNTIL JOHN COFFMAN'S
; VERSION IS READY.
;______________________________________________________________________________________________________________________
;
;
#INCLUDE "std.asm"
;
.ORG $0000
;
DI ; NO INTERRUPTS
IM 1 ; INTERRUPT MODE 1
LD SP,$HBX_LOC ; START WITH SP BELOW HBIOS PROXY LOCATION
;
#IF ((PLATFORM == PLT_N8) | (PLATFORM == PLT_MK4))
; SET BASE FOR CPU IO REGISTERS
LD A,CPU_BASE
OUT0 (CPU_ICR),A
; SET DEFAULT CPU CLOCK MULTIPLIERS (XTAL / 2)
XOR A
OUT0 (CPU_CCR),A
OUT0 (CPU_CMR),A
; SET DEFAULT WAIT STATES
LD A,$F0
OUT0 (CPU_DCNTL),A
#IF (Z180_CLKDIV >= 1)
; SET CLOCK DIVIDE TO 1 RESULTING IN FULL XTAL SPEED
LD A,$80
OUT0 (CPU_CCR),A
#ENDIF
#IF (Z180_CLKDIV >= 2)
; SET CPU MULTIPLIER TO 1 RESULTINT IN XTAL * 2 SPEED
LD A,$80
OUT0 (CPU_CMR),A
#ENDIF
; SET DESIRED WAIT STATES
LD A,0 + (Z180_MEMWAIT << 6) | (Z180_IOWAIT << 4)
OUT0 (CPU_DCNTL),A
; MMU SETUP
LD A,$80
OUT0 (CPU_CBAR),A ; SETUP FOR 32K/32K BANK CONFIG
XOR A
OUT0 (CPU_BBR),A ; BANK BASE = 0
LD A,(RAMSIZE + RAMBIAS - 64) >> 2
OUT0 (CPU_CBR),A ; COMMON BASE = LAST (TOP) BANK
#ENDIF
;
; EMIT FIRST SIGN OF LIFE TO SERIAL PORT
;
CALL XIO_INIT ; INIT SERIAL PORT
LD HL,STR_BOOT ; POINT TO MESSAGE
CALL XIO_OUTS ; SAY HELLO
;
; COPY OURSELF TO HIRAM
;
; NOTE: STACK IS WIPED OUT, STACK IS ASSUMED TO BE EMPTY HERE!!!!
;
LD HL,$0000 ; COPY MEMORY FROM LOMEM (0000H)
LD DE,$8000 ; TO HIMEM (8000H)
LD BC,COD_SIZ ; COPY CODE
LDIR
;
CALL XIO_DOT ; MARK PROGRESS
;
JP PHASE2 ; JUMP TO PHASE 2 IN UPPER MEMORY
;
STR_BOOT .DB PLATFORM_NAME, '$'
;
; IMBED DIRECT SERIAL I/O ROUTINES
;
#INCLUDE "xio.asm"
;
;______________________________________________________________________________________________________________________
;
; THIS IS THE PHASE 2 CODE THAT MUST EXECUTE IN UPPER MEMORY
;
.ORG $ + $8000 ; WE ARE NOW EXECUTING IN UPPER MEMORY
;
PHASE2:
CALL XIO_DOT ; MARK PROGRESS
CALL XIO_CRLF ; FINISH LINE
CALL XIO_CRLF ; A BLANK LINE FOR SPACING
;
; SWAP LOMEM TO BANK 1 AND CHAIN TO $0000
;
; LD A,1 ; SPECIFY PAGE 1
; CALL ROMPG ; PUT ROM PAGE 1 IN LOW RAM
LD A,BID_COMIMG ; CHAIN TO COMMON IMAGE IN ROM
CALL PGSEL ; SELECT THE PAGE
JP $0000 ; CHAIN EXECUTION TO IT
;______________________________________________________________________________________________________________________
;
; NOTE THAT MEMORY MANAGER CODE IS IN UPPER MEMORY!
;
#INCLUDE "memmgr.asm"
;______________________________________________________________________________________________________________________
;
; PAD OUT REMAINDER OF PAGE
;
.ORG $ - $8000 ; ORG BACK TO LOWER MEMORY
COD_SIZ .EQU $ ; SIZE OF CODE
.FILL $8000 - $,$FF ; PAD OUT REMAINDER OF ROM SPACE
;
.END