FreeCalypso > hg > freecalypso-tools
annotate target-utils/libbase/waitarm.S @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Mon, 11 Feb 2019 00:00:19 +0000 |
| parents | 6228d27738d1 |
| children | 06ad5e30e8d0 |
| rev | line source |
|---|---|
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453
6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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1 /* |
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6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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2 * This assembly module provides a wait_ARM_cycles() function just like |
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6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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3 * in TI's firmware; it is meant to gradually replace and phase out |
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6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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4 * osmo_delay_ms(). One loop count for this function equals 5 ARM clock |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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5 * cycles when running out of IRAM. |
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6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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6 */ |
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6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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7 |
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6228d27738d1
target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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8 .text |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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9 .code 32 |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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10 .globl wait_ARM_cycles |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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11 wait_ARM_cycles: |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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12 cmp r0, #0 |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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13 bxeq lr |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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14 1: sub r0, r0, #1 |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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15 cmp r0, #0 |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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16 bne 1b |
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target-utils: wait_ARM_cycles() added to libbase
Mychaela Falconia <falcon@freecalypso.org>
parents:
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17 bx lr |
