Mercurial > pub > dyncall > dyncall
annotate dyncall/dyncall_call_arm32_thumb_gas.s @ 315:3840e0188520
- allowing lookup of running executable's path by passing NULL to dynload's dlGetLibraryPath()
| author | Tassilo Philipp |
|---|---|
| date | Wed, 06 Nov 2019 14:13:49 +0100 |
| parents | 00dd15cc5c87 |
| children | 351bb41d3bb1 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 | |
| 3 Package: dyncall | |
| 4 Library: dyncall | |
| 5 File: dyncall/dyncall_call_arm32_thumb_gas.s | |
| 6 Description: ARM Thumb call kernel implementation for GNU assembler. | |
| 7 License: | |
| 8 | |
| 9 Copyright (c) 2007-2011 Daniel Adler <dadler@uni-goettingen.de>, | |
| 10 Tassilo Philipp <tphilipp@potion-studios.com> | |
| 11 | |
| 12 Permission to use, copy, modify, and distribute this software for any | |
| 13 purpose with or without fee is hereby granted, provided that the above | |
| 14 copyright notice and this permission notice appear in all copies. | |
| 15 | |
| 16 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
| 17 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
| 18 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
| 19 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
| 20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
| 21 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
| 22 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
| 23 | |
| 24 */ | |
| 25 | |
| 26 | |
| 27 .text | |
| 28 #if !defined(__thumb2__) | |
| 29 .code 16 /* THUMB mode */ | |
| 30 #endif | |
| 31 | |
| 32 .globl dcCall_arm32_thumb | |
| 33 | |
| 34 /* Main dyncall call. */ | |
| 35 .thumb_func | |
| 36 dcCall_arm32_thumb: | |
| 37 | |
| 38 /* Prolog. This function never needs to spill inside its prolog, so just store the permanent registers. */ | |
|
175
00dd15cc5c87
- fixed ARM32-THUMB stack alignment issues (found on Cortex-m0, thanks Darren Whobrey!)
cslag
parents:
27
diff
changeset
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39 /* Code below is not using high registers, so not storing them in prolog, which is more involved with thumb, anyways. */ |
|
00dd15cc5c87
- fixed ARM32-THUMB stack alignment issues (found on Cortex-m0, thanks Darren Whobrey!)
cslag
parents:
27
diff
changeset
|
40 push {%r4-%r7, %r14} /* Frame ptr, permanent registers, link register -> save area on stack. */ |
| 0 | 41 mov %r7, %r13 /* Set frame ptr. */ |
|
175
00dd15cc5c87
- fixed ARM32-THUMB stack alignment issues (found on Cortex-m0, thanks Darren Whobrey!)
cslag
parents:
27
diff
changeset
|
42 sub %r13, #4 /* Realign stack to 8 bytes (b/c we stored 5 regs = 20b). */ |
| 0 | 43 |
| 44 /* Call. */ | |
| 45 mov %r4, %r0 /* Move 'fptr' to r4 (1st argument is passed in r0). */ | |
| 46 mov %r5, %r1 /* Move 'args' to r5 (2nd argument is passed in r1). */ | |
| 47 mov %r6, %r2 /* Move 'size' to r6 (3rd argument is passed in r2). */ | |
| 48 | |
| 49 cmp %r6, #16 /* Jump to call if no more than 4 arguments. */ | |
| 50 ble call | |
| 51 | |
| 52 sub %r6, #16 /* Size of remaining arguments. */ | |
| 53 mov %r0, %r13 /* Set stack pointer to top of stack. */ | |
| 54 sub %r0, %r0, %r6 | |
| 55 lsr %r0, #3 /* Align stack on 8 byte boundaries. */ | |
| 56 lsl %r0, #3 | |
| 57 mov %r13, %r0 | |
| 58 | |
| 59 add %r1, #16 /* Let r1 point to remaining arguments. */ | |
| 60 mov %r2, #0 /* Init byte counter to 0. */ | |
| 61 .thumb_func | |
| 62 pushArgs: | |
| 63 ldrb %r3, [%r1, %r2] /* Load a byte into r3. */ | |
| 64 strb %r3, [%r0, %r2] /* Push byte onto stack. */ | |
| 65 add %r2, %r2, #1 /* Increment byte counter. */ | |
| 66 cmp %r2, %r6 | |
| 67 bne pushArgs | |
| 68 .thumb_func | |
| 69 call: | |
| 70 ldmia %r5!, {%r0-%r3} /* Load first 4 arguments for new call into r0-r3. */ | |
| 71 | |
| 72 /* 'blx %r4' workaround for ARMv4t in THUMB: */ | |
| 73 mov %r6, %r15 /* Load PC+2 instructions from here */ | |
| 74 add %r6, #5 /* Increment by 2 instructions (Address of 'Epilog') and set bit 0 (THUMB) */ | |
| 75 mov %r14, %r6 /* Store in link register. */ | |
| 76 bx %r4 /* Branch and force THUMB-mode return (LR bit 0 set). */ | |
| 77 | |
| 78 /* Epilog. */ | |
| 79 mov %r13, %r7 /* Reset stack ptr. */ | |
| 80 pop {%r4-%r7, %r15} /* Restore permanent registers and program counter. (Force a stay in THUMB in ARMv4, whether ARMv5 can return in ARM or THUMB depending on the bit 0. */ | |
| 81 |