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annotate target-utils/libbase/waitarm.S @ 698:9ecbf1bf2e1b

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fc-iram: added '+' to getopt magic string like in fc-xram Both fc-iram and fc-xram now support secondary program invokation. If the user needs to pass some options to the secondary program, we don't want fc-iram or fc-xram to claim these options as its own, thus we need to stop getopt() from reordering arguments. This fix was already implemented in fc-xram a long time ago, but the issue was overlooked when secondary program invokation ability was added to fc-iram.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 31 Mar 2020 03:23:26 +0000
parents 06ad5e30e8d0
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
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1 /*
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06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
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2 * This assembly module provides a wait_ARM_cycles() function similar to
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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3 * the one in TI's firmware; it is meant to gradually replace and phase out
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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4 * osmo_delay_ms(). One loop count for this function equals 4 ARM clock
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
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parents: 453
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5 * cycles when running out of IRAM; if the ARM clock is 52 MHz, 13 loop counts
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
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parents: 453
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6 * equal one microsecond.
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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7 *
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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8 * Note the instruction sequence difference from TI's firmware version:
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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9 * we use the SUBS instruction (equivalent of plain SUB in Thumb) and omit
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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10 * the CMP, which is why our version is 4 cycles per loop (when running
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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11 * out of IRAM), as opposed to 5 cycles per loop (plus wait states as they
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
Mychaela Falconia <falcon@freecalypso.org>
parents: 453
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12 * execute from flash) in TI's fw version.
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13 */
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6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
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15 .text
6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
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16 .code 32
6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
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17 .globl wait_ARM_cycles
6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
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18 wait_ARM_cycles:
6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
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19 cmp r0, #0
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20 bxeq lr
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21 1: subs r0, r0, #1
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22 bne 1b
6228d27738d1 target-utils: wait_ARM_cycles() added to libbase
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23 bx lr