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annotate target-utils/libbase/waitarm.S @ 926:6a0aa8d36d06

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rvinterf backslash escape: introduce libprint The new helper function library named libprint is meant to replace the badly misnamed libg23, and will soon contain functions for printing all of the same kinds of GPF TST packets that are now handled in libg23. However, we are also moving safe_print_trace() from libasync to this new library, and changing it to emit our new backslash escape format.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 23 May 2023 03:47:46 +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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2 * This assembly module provides a wait_ARM_cycles() function similar to
06ad5e30e8d0 target-utils: wait_ARM_cycles() changed to 4 cycles per loop
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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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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
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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
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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
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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
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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
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23 bx lr