nand.s

Samsung公司S3C6400芯片的BSP源码包

;
; Copyright (c) Microsoft Corporation.  All rights reserved.
;
;
; Use of this source code is subject to the terms of the Microsoft end-user
; license agreement (EULA) under which you licensed this SOFTWARE PRODUCT.
; If you did not accept the terms of the EULA, you are not authorized to use
; this source code. For a copy of the EULA, please see the LICENSE.RTF on your
; install media.
;
;
; NAND Flash Related Routines
;

	INCLUDE kxarm.h

	TEXTAREA

;----------------------------------------------
NFDATA		EQU		(0xb0200010)
;----------------------------------------------

;----------------------------------------------
; Read one sector.  Buffer (r0) must be aligned.
;
	LEAF_ENTRY RdPage512

		stmfd	sp!,{r1 - r11}

		ldr		r1, =NFDATA
		mov		r2, #0x200
1
		ldr		r4, [r1]
		ldr		r5, [r1]
		ldr		r6, [r1]
		ldr		r7, [r1]
		ldr		r8, [r1]
		ldr		r9, [r1]
		ldr		r10, [r1]
		ldr		r11, [r1]

		stmia	r0!, {r4 - r11}
		subs    	r2, r2, #32
		bne		%B1

		ldmfd	sp!, {r1 - r11}

	IF Interworking :LOR: Thumbing
		bx		lr
	ELSE
		mov		pc, lr	; return
	ENDIF

;----------------------------------------------
; Read one sector.  Handles case where buffer (r0) is unaligned.
;
	LEAF_ENTRY RdPage512Unalign

		stmfd	sp!,{r1 - r12}

		ldr		r1, =NFDATA
		mov		r2, #480

		; Calculate number of unaligned bytes to read (r12 = 4 - (r0 & 3))
		and		r12, r0, #3
		rsb		r12, r12, #4
		mov		r3, r12

rd_unalign1
		; Read unaligned bytes
		ldrb		r4, [r1]
		strb		r4, [r0]
		add		r0, r0, #1
		subs		r3, r3, #1
		bne		rd_unalign1

rd_main
		; Read 480 bytes (32 x 15)
		ldr		r4, [r1]
		ldr		r5, [r1]
		ldr		r6, [r1]
		ldr		r7, [r1]
		ldr		r8, [r1]
		ldr		r9, [r1]
		ldr		r10, [r1]
		ldr		r11, [r1]

		stmia	r0!,{r4-r11}
		subs		r2, r2, #32
		bne		rd_main

		; Read 28 bytes
		ldr		r4, [r1]
		ldr		r5, [r1]
		ldr		r6, [r1]
		ldr		r7, [r1]
		ldr		r8, [r1]
		ldr		r9, [r1]
		ldr		r10, [r1]
		stmia	r0!, {r4 - r10}

		; Read trailing unaligned bytes
		rsbs		r12, r12, #4
		beq		rd_exit

rd_unalign2
		ldrb		r4, [r1]
		strb		r4, [r0]
		add		r0, r0, #1
		subs		r12, r12, #1
		bne		rd_unalign2
rd_exit
		ldmfd	sp!, {r1 - r12}

	IF Interworking :LOR: Thumbing
		bx		lr
	ELSE
		mov		pc, lr	; return
	ENDIF


;----------------------------------------------
; Write one sector.  Buffer (r0) must be aligned.
;

	LEAF_ENTRY WrPage512

		stmfd	sp!,{r1 - r11}

		ldr		r1, =NFDATA
		mov		r2, #0x200
1
		ldmia	r0!, {r4 - r11}

		str		r4, [r1]
		str		r5, [r1]
		str		r6, [r1]
		str		r7, [r1]
		str		r8, [r1]
		str		r9, [r1]
		str		r10, [r1]
		str		r11, [r1]

		subs		r2, r2, #32
		bne		%B1

		ldmfd	sp!, {r1 - r11}

	IF Interworking :LOR: Thumbing
		bx		lr
	ELSE
		mov		pc, lr	; return
	ENDIF

;----------------------------------------------
; Writes one sector.  Handles case where buffer (r0) is unaligned.
;

	LEAF_ENTRY WrPage512Unalign

		stmfd	sp!,{r1 - r11}

		ldr		r1, =NFDATA
		mov		r2, #480

		; Calculate number of unaligned bytes to read (r12 = 4 - (r0 & 3))
		and		r12, r0, #3
		rsb		r12, r12, #4
		mov		r3, r12

wr_unalign1
		; Write unaligned bytes
		ldrb		r4, [r0]
		strb		r4, [r1]
		add		r0, r0, #1
		subs		r3, r3, #1
		bne		wr_unalign1

wr_main
		; Write 480 bytes (32 x 15)
		ldmia	r0!, {r4-r11}

		str		r4, [r1]
		str		r5, [r1]
		str		r6, [r1]
		str		r7, [r1]
		str		r8, [r1]
		str		r9, [r1]
		str		r10, [r1]
		str		r11, [r1]

		subs		r2, r2, #32
		bne		wr_main

		; Write 28 bytes
		ldmia	r0!, {r4 - r10}
		str		r4, [r1]
		str		r5, [r1]
		str		r6, [r1]
		str		r7, [r1]
		str		r8, [r1]
		str		r9, [r1]
		str		r10, [r1]

		; Write trailing unaligned bytes
		rsbs		r12, r12, #4
		beq		wr_exit

wr_unalign2
		ldrb		r4, [r0]
		strb		r4, [r1]
		add		r0, r0, #1
		subs		r12, r12, #1
		bne		wr_unalign2

wr_exit
		ldmfd	sp!, {r1 - r11}

	IF Interworking :LOR: Thumbing
		bx		lr
	ELSE
		mov		pc, lr	; return
	ENDIF

;----------------------------------------------
; Read page/sector information.  This includes logical sector number
; and block status flags (RO, OEM-defined, etc.).
;

	LEAF_ENTRY RdPageInfo

		stmfd	sp!, {r1 - r4}

		ldr		r1, =NFDATA
		ldr		r3, [r1]
		ldr		r4, [r1]
		stmia	r0!, {r3 - r4}
		ldmfd	sp!, {r1 - r4}

	IF Interworking :LOR: Thumbing
		bx		lr
	ELSE
		mov		pc, lr	; return
	ENDIF

;----------------------------------------------
; Store page/sector information.  This includes logical sector number
; and block status flags (RO, OEM-defined, etc.).
;

	LEAF_ENTRY WrPageInfo

		stmfd	sp!, {r1 - r3}

		ldr		r1, =NFDATA
		ldmia	r0!, {r2 - r3}
		str		r2, [r1]
		str		r3, [r1]
		ldmfd	sp!, {r1 - r3}

	IF Interworking :LOR: Thumbing
		bx		lr
	ELSE
		mov		pc, lr	; return
	ENDIF

	END