annotate target-utils/libc/memcpy.S @ 965:2969032bdfac

fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing The only 100% safe way to pass a NULL pointer as a function argument in K&R C is to cast 0 to a pointer type; failing to do so may cause mysterious bugs (invalid stack frames or garbage in argument registers) on 64-bit machines. This issue has already been fixed in most of FC host tools, but I just found some missed spots: passing of NULL UDH to PDU encoding functions in fcup-smsend[mult] in the case of single (not concatenated) SMS.
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 01 Sep 2023 07:33:51 +0000
parents f4619719834f
children
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f4619719834f target-utils/libc: our own memcpy assembly implementation
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1 .text
f4619719834f target-utils/libc: our own memcpy assembly implementation
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2 .code 32
f4619719834f target-utils/libc: our own memcpy assembly implementation
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3 .globl memcpy
f4619719834f target-utils/libc: our own memcpy assembly implementation
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4 memcpy:
f4619719834f target-utils/libc: our own memcpy assembly implementation
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5 1: subs r2, r2, #1
f4619719834f target-utils/libc: our own memcpy assembly implementation
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6 ldrcsb r3, [r1], #1
f4619719834f target-utils/libc: our own memcpy assembly implementation
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7 strcsb r3, [r0], #1
f4619719834f target-utils/libc: our own memcpy assembly implementation
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8 bhi 1b
f4619719834f target-utils/libc: our own memcpy assembly implementation
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9 bx lr