ARM R5f settting stack on TCM error

Question

I'm trying to set ARM cortex R5f processor stack on TCM to measure processor performance. but each time the stack accessed, to processor goes to abort handler.

when I write data on address 0x41000000 (BTCM) I got no error.

I got the following status registers :

CP15_DFSR = 0x800

SD axi_decode_error RW : write_access_abort

 CP15_IFSR = x0000

SD axi_decode_error

CP15_DFAR = 0x40FFFFF4

Holds the address of the fault when a synchronous abort occurs.

BTCM configuration

; The Cortex-R5 has
; 4K BTCM from 0x41000000 to 0x41000FFF 
        MRC p15, 0, r0, c9, c1, 0       ; Read BTCM Region Register
        ; r0 now contains ATCM size in bits [6:2]
        BFC     r0,#12,#20
        ORR r0, r0, #1                  ; Enable it
        LDR     r1, =||Image$$BTCM$$Base||
        ORR r0, r0, r1                  ; Set BTCM base address
        MCR p15, 0, r0, c9, c1, 0       ; Write BTCM Region Register

MPU configuration

 ; Region - BTCM
        ADD     r1, r1, #1
        MCR     p15, 0, r1, c6, c2, 0       ; Set memory region number register
        LDR     r2, =||Image$$BTCM$$Base||
        MCR     p15, 0, r2, c6, c1, 0       ; Set region base address register
        LDR     r2, =0x0 :OR: (Region_4K << 1) :OR: Region_Enable
        MCR     p15, 0, r2, c6, c1, 2       ; Set region size & enable register
        LDR     r2, =0x0 :OR: (Full_Access << 8) :OR: Normal_nShared
        MCR     p15, 0, r2, c6, c1, 4       ; Set region access control register

configure stack

 MOV R1, 0x4100000 ;------------------------ set stack @ in BTCM -------------------  0x41001000
    ADD R1, R1, 0x1000


; Set up UNDEF registers
    mov     r0, #ARM_MODE_UNDEF:OR:I_BIT:OR:F_BIT
    msr     CPSR_cxsf, r0
    mov     r13,r1
    mov r14, #0
    msr spsr_cxsf, r6
    sub     r1,r1,#UNDEF_STACK_SIZE

; Set up ABORT registers
    mov     r0, #ARM_MODE_ABORT:OR:I_BIT:OR:F_BIT
    msr     CPSR_cxsf, r0
    mov     r13,r1
    mov r14, #0
    msr spsr_cxsf, r6
    sub     r1,r1,#ABORT_STACK_SIZE

; Set up Fast Interrupt registers
    mov     r0, #ARM_MODE_FIQ:OR:I_BIT:OR:F_BIT
    msr     CPSR_cxsf, r0
    mov     r13,r1
    mov r8, #0
    mov r9, #0
    mov r10, #0
    mov r11, #0
    mov r12, #0
    mov r14, #0
    msr spsr_cxsf, r6
    sub     r1,r1,#FIQ_STACK_SIZE

; Set up Interrupt registers
    mov     r0, #ARM_MODE_IRQ:OR:I_BIT:OR:F_BIT
    msr     CPSR_cxsf, r0
    mov     r13,r1
    mov r14, #0
    msr spsr_cxsf, r6
    sub     r1,r1,#IRQ_STACK_SIZE

; Set up supervisor registers
    mov     r0, #ARM_MODE_SVC:OR:I_BIT:OR:F_BIT
    msr     CPSR_cxsf, r0
    mov     r13,r1
    mov r14, #0
    msr spsr_cxsf, r6
    sub     r1,r1,#SVC_STACK_SIZE

; Set up System registers
    mov     r0, #ARM_MODE_SYS:OR:I_BIT:OR:F_BIT
    msr     CPSR_cxsf, r0
    mov     r13,r1
    mov r14, #0

jump to main

B main

What do the *FSR/*FAR registers have to say about the abort? Even just knowing the syndrome (e.g. external abort vs. permission fault) should narrow things down significantly. — Notlikethat, Jul 27 '15 at 07:49
@Notlikethat I posted the status register in the question. any clue? — bouqbouq, Jul 27 '15 at 08:20
@Notlikethat it worked just by putting `mov r1, #0x40001000 mov r13, r1`insteed of `mov r1, 0x40001000 mov r13, r1` . the `#`made the difference. what's the difference here?? — bouqbouq, Jul 27 '15 at 08:47
Well, from the fault address you've clearly run off the bottom of the TCM - how big are all those *_STACK_SIZE constants? — Notlikethat, Jul 27 '15 at 09:08

score 1 · Answer 1 · answered Jul 28 '15 at 08:29

1

Either your total "STACK_SIZE" constants are bigger than your TCM, or your program is using more than STACK_SIZE bytes and running over its assigned space. The fault is because you are trying to access below your TCM address.

answered Jul 28 '15 at 08:29

solidpixel

10,688
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in fact it worked just by putting `mov r1, #0x40001000` `mov r13, r1`insteed of `mov r1, 0x40001000` `mov r13, r1` . the #made the difference. do you think it may be the problem???? – bouqbouq Jul 28 '15 at 08:31
Probably - you need the "#" to make it see a literal constant. – solidpixel Jul 28 '15 at 08:33

ARM R5f settting stack on TCM error

1 Answers1