Files
aqhomecontrol/avr/modules/flash/flash1p.asm
2025-03-24 00:18:50 +01:00

341 lines
8.2 KiB
NASM

; ***************************************************************************
; copyright : (C) 2025 by Martin Preuss
; email : martin@libchipcard.de
;
; ***************************************************************************
; * This file is part of the project "AqHome". *
; * Please see toplevel file COPYING of that project for license details. *
; ***************************************************************************
.equ FLASH_PAGESIZE = (PAGESIZE*2)
; ***************************************************************************
; data
.dseg
flashPageNum: .byte 2
flashPageBuffer: .byte FLASH_PAGESIZE
; ***************************************************************************
; code
.cseg
; ---------------------------------------------------------------------------
; @routine Flash_Init
;
; @clobbers R16
Flash_Init:
ldi r16, 0xff
sts flashPageNum, r16
sts flashPageNum+1, r16
ret
; @end
; ---------------------------------------------------------------------------
; @routine Flash_Fini
;
; @clobbers (R0, R1, R16, R18, R19, R20, R21, R24, R25, X)
Flash_Fini:
push r15
in r15, SREG
cli
rcall flash1pEndPage ; (R0, R1, R16, R18, R19, R20, R24, R25, X)
out SREG, r15
pop r15
ret
; @end
; ---------------------------------------------------------------------------
; @routine Flash_WriteData
;
; @param Z destination address in FLASH memory (byte address as for LPM!)
; @param Y source address
; @param r17 number of bytes to write
; @clobbers (R0, R1, R16, R18, R19, R20, R24, R25, X)
Flash_WriteData:
push r15
in r15, SREG
cli
Flash_WriteData_loop:
tst r17
breq Flash_WriteData_done
rcall flashWriteData ; (R0, R1, R16, R18, R19, R20, R24, R25, X)
rjmp Flash_WriteData_loop
Flash_WriteData_done:
out SREG, r15
pop r15
ret
; @end
; ---------------------------------------------------------------------------
; @routine flashWriteData
;
; Interrupts must be disabled!
;
; @return Z next position
; @return R17 remainder of bytes to flash
; @param Z position to flash data to
; @param Y source pointer
; @param R17 number of bytes to flash
; @clobbers R16, R18, R24, R25, X (R0, R1, R19, R20)
flashWriteData:
rcall flashCheckCurrentValid ; (r18, r19)
brcc flashWriteData_beginPage
rcall flashWriteCheckPage ; (r18, r19)
brcs flashWriteData_calcPosAndLength ; still inside current page, jump
rcall flash1pEndPage ; (R0, R1, R16, R18, R19, R20, R24, R25, X)
flashWriteData_beginPage:
rcall flash1pBeginPage ; (r16, r24, r25, X)
flashWriteData_calcPosAndLength:
rcall flashCalcPosAndLength ; (r24, r25)
; X=abs pos in buffer, r18=bytes to read, r17=bytes initially requested
; prepare data for return
sub r17, r18 ; r17 holds remainder
add zl, r18 ; Z points to next data
adc zh, r18 ; only add carry flag
sub zh, r18
flashWriteData_copyLoop:
ld r16, Y+
st X+, r16
dec r18
brne flashWriteData_copyLoop
ret
; @end
; ---------------------------------------------------------------------------
; @routine flashCalcPosAndLength
;
; @return X absolute write position inside buffer
; @return R18 bytes to write
; @param Z destination pos
; @param R17 number of bytes to write
; @clobbers r24, r25
flashCalcPosAndLength:
; calc offset into buffer
mov r24, zl
andi r24, (FLASH_PAGESIZE-1) ; r24=rel pos inside buffer
ldi r25, FLASH_PAGESIZE
sub r25, r24 ; r25=bytes left inside page
mov r18, r17
cp r25, r17 ; bytes to read > bytes left in page?
brcc flashCalcPosAndLength_l1 ; no: jump
mov r18, r25 ; yes: cut r18 to number of bytes left in page
flashCalcPosAndLength_l1:
ldi xl, LOW(flashPageBuffer) ; set X to pos within page buffer
ldi xh, HIGH(flashPageBuffer)
add xl, r24
adc xh, r24
sub xh, r24
ret
; @end
; ---------------------------------------------------------------------------
; @routine flashWriteCheckPage
;
; check whether the given address is inside the current page in buffer
;
; @return CFLAG set if same page, cleared otherwise
; @param Z address to write to
; @clobbers r18, r19
flashWriteCheckPage:
; check low byte of page
mov r18, zl
andi r18, LOW(~(FLASH_PAGESIZE-1))
lds r19, flashPageNum
cp r18, r19
brne flashWriteCheckPage_ClcRet
; check high byte of page
mov r18, zh
andi r18, HIGH(~(FLASH_PAGESIZE-1))
lds r19, flashPageNum+1
cp r18, r19
brne flashWriteCheckPage_ClcRet
sec
ret
flashWriteCheckPage_ClcRet:
clc
ret
; @end
; ---------------------------------------------------------------------------
; @routine flashCheckCurrentValid
;
; check whether the page buffer contains a valid page (e.g. flashPageNum is not 0xffff)
;
; @return CFLAG set if current page is valid, cleared otherwise
; @clobbers r18, r19
flashCheckCurrentValid:
lds r18, flashPageNum
lds r19, flashPageNum+1
and r18, r19
inc r18
breq flashCheckCurrentValid_ClcRet
sec
ret
flashCheckCurrentValid_ClcRet:
clc
ret
; @end
; ---------------------------------------------------------------------------
; @routine flash1pBeginPage
;
; Interrupts must be disabled!
;
; @param Z Address to read from (byte address as for LPM!)
; @clobbers (r16, r24, r25, X)
flash1pBeginPage:
push zl
push zh
andi zl, LOW(~(FLASH_PAGESIZE-1))
andi zh, HIGH(~(FLASH_PAGESIZE-1))
sts flashPageNum, zl
sts flashPageNum+1, zh
rcall flash1pReadPageIntoSram ; r16, r24, r25, X, Z
pop zh
pop zl
ret
; @end
; ---------------------------------------------------------------------------
; @routine flash1pEndPage
;
; Interrupts must be disabled!
;
; @clobbers (R0, R1, R16, R18, R19, R20, R24, R25, X)
flash1pEndPage:
rcall flashCheckCurrentValid ; (r18, r19)
brcs flash1pEndPage_write
ret
flash1pEndPage_write:
push zl
push zh
rcall flash1pWritePage ; (r0, r1, r20, r24, r25, X, Z)
pop zh
pop zl
ret
; @end
; ---------------------------------------------------------------------------
; @routine flash1pReadPageIntoSram
;
; Interrupts must be disabled!
;
; @param Z Address to read from (byte address as for LPM!)
; @clobbers r16, r24, X, Z
flash1pReadPageIntoSram:
ldi xl, LOW(flashPageBuffer)
ldi xh, HIGH(flashPageBuffer)
ldi r24, LOW(FLASH_PAGESIZE)
flash1pReadPageIntoSram_loop:
lpm r16, Z+
st X+, r16
adiw ZH:ZL, 1
dec r24
brne flash1pReadPageIntoSram_loop
ret
; @end
; ---------------------------------------------------------------------------
; flash1pWritePage
;
; Interrupts must be disabled!
;
; @clobbers r0, r1, r20, r24, r25, X, Z
flash1pWritePage:
lds zl, flashPageNum
lds zh, flashPageNum+1
; erase page
ldi r20, (1<<PGERS) + (1<<SPMEN) ; enable next SPM, erase page (R1/R0 ignored)
rcall flash1pDoSpm ; (R16)
; copy from SDRAM into MCUs temporary page buffer
ldi xl, LOW(flashPageBuffer)
ldi xh, HIGH(flashPageBuffer)
ldi r24, LOW(PAGESIZE)
push zl
push zh
flash1pWritePages_loop:
ld r0, X+ ; read source data from buffer (low)
ld r1, X+ ; read source data from buffer (high)
ldi r20, (1<<SPMEN) ; enable next SPM, write R1:R0 into temp page buffer
rcall flash1pDoSpm ; (R16)
adiw zh:zl, 2
dec r24
brne flash1pWritePages_loop
pop zh
pop zl
; transfer data from temporary page buffer into FLASH memory
ldi r20, (1<<PGWRT) + (1<<SPMEN) ; enable next SPM, write page (R1/R0 ignored)
rcall flash1pDoSpm ; (R16)
ret
; @end
; ---------------------------------------------------------------------------
; flash1pDoSpm
;
; wait until possible previous SPM finished and then issue another SPM.
;
; IN:
; - R20: value for register SPMCR
; - R0: low value for SPM
; - R1: high value for SPM
; - Z : address for SPM (byte address!)
; OUT:
; - nothing
; REGS: R16
flash1pDoSpm:
flash1pDoSpm_wait: ; wait for possibly previous SPM to complete
in r16, SPMCSR
sbrc r16, SPMEN
rjmp flash1pDoSpm_wait
; SPM timed sequence
out SPMCSR, r20
spm
ret