openpcd/firmware/lib/bitops.h @ master
1 | 5ab655eb | (no author) | .macro bitop, instr |
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2 | and r2, r0, #7 |
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3 | mov r3, #1 |
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4 | mov r3, r3, lsl r2 |
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5 | save_and_disable_irqs ip |
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6 | ldrb r2, [r1, r0, lsr #3] |
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7 | \instr r2, r2, r3 |
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8 | strb r2, [r1, r0, lsr #3] |
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9 | restore_irqs ip |
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10 | mov pc, lr |
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11 | .endm |
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12 | |||
13 | /**
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14 | * testop - implement a test_and_xxx_bit operation.
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15 | * @instr: operational instruction
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16 | * @store: store instruction
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17 | *
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18 | * Note: we can trivially conditionalise the store instruction
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19 | * to avoid dirting the data cache.
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20 | */
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21 | .macro testop, instr, store |
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22 | add r1, r1, r0, lsr #3 |
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23 | and r3, r0, #7 |
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24 | mov r0, #1 |
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25 | save_and_disable_irqs ip |
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26 | ldrb r2, [r1] |
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27 | tst r2, r0, lsl r3 |
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28 | \instr r2, r2, r0, lsl r3 |
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29 | \store r2, [r1] |
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30 | restore_irqs ip |
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31 | moveq r0, #0 |
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32 | mov pc, lr |
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33 | .endm |