I need to swap to elements in an array in ARM Assembly, I have the code started I just need help finishing the final subroutine. the swap_array subroutine swaps two elements of an array, given the address of the array and two (valid) indexes of that array. Use a temp variable on the stack as part of the swap.

@ Swap the array data MOV R1, #1 STMFD SP!, {R1} @ Push j MOV R1, #7 STMFD SP!, {R1} @ Push i LDR R1, =Data STMFD SP!, {R1} @ Push a BL swap_array ADD SP, SP, #12 BL PrintLF

@-------------------------------------------------------

PrintLF:

/*

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Prints the line feed character ( )

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Uses:

R0 - set to ' '

(SWI_PrChr automatically prints to stdout)

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*/

STMFD SP!, {R0, LR}

MOV R0, #' ' @ Define the line feed character

SWI SWI_PrChr @ Print the character to Stdout

LDMFD SP!, {R0, PC}

@-------------------------------------------------------

swap_array:

/*

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Swaps location of two values in list. swap(a, i, j)

Parameters passed on stack:

Address of list

Index of first value (i)

Index of second value (j)

Local variable

temp

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Uses:

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*/

STMFD SP!, {FP, LR} @ push frame pointer and link register onto the stack

MOV FP, SP @ save current stack top to frame pointer

SUB SP, SP, #4 @ set aside space for temp

STMFD SP!, {?} @ preserve other registers

@ your code here

LDMFD SP!, {?} @ pop preserved registers

ADD SP, SP, #4 @ remove local storage

LDMFD SP!, {FP, PC} @ pop frame pointer and program counter

@-----------------------------------------------------

.data Data: .byte 4,5,9,0,8,0,8,7,1 @ The list of data _Data: @ End of list address .end