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* 3857Kartik K. Agaram2017-05-131-12/+0
* 3856Kartik K. Agaram2017-05-131-0/+1
* 3854Kartik K. Agaram2017-05-139-39/+39
* 3853Kartik K. Agaram2017-05-121-2/+13
* 3852Kartik K. Agaram2017-05-123-2/+35
* 3844Kartik K. Agaram2017-05-061-43/+4
* 3843Kartik K. Agaram2017-05-062-7/+10
* 3831Kartik K. Agaram2017-04-181-1/+1
* 3825Kartik K. Agaram2017-04-161-0/+6
* 3824 - experiment: stop buffering in termboxKartik K. Agaram2017-04-168-35/+0
* 3806Kartik K. Agaram2017-03-211-9/+4
* 3797Kartik K. Agaram2017-03-152-2/+0
* 3796Kartik K. Agaram2017-03-141-26/+30
* 3795Kartik K. Agaram2017-03-142-5/+5
* 3794Kartik K. Agaram2017-03-141-2/+2
* 3793Kartik K. Agaram2017-03-142-63/+63
* 3790Kartik K. Agaram2017-03-121-1/+4
* 3789Kartik K. Agaram2017-03-121-0/+1
* 3748Kartik K. Agaram2017-02-281-1/+1
* 3733Kartik K. Agaram2017-01-111-1/+1
* 3731Kartik K. Agaram2017-01-111-1/+2
* 3706Kartik K. Agaram2016-12-111-2/+2
* 3705 - switch to tested file-system primitivesKartik K. Agaram2016-12-118-256/+393
* 3700Kartik K. Agaram2016-11-284-89/+51
* 3699Kartik K. Agaram2016-11-284-13/+10
* 3698Kartik K. Agaram2016-11-276-142/+148
* 3656Kartik K. Agaram2016-11-103-5/+5
* 3599Kartik K. Agaram2016-10-271-2/+4
* 3565Kartik K. Agaram2016-10-232-2/+2
* 3561Kartik K. Agaram2016-10-224-9/+9
* 3552Kartik K. Agaram2016-10-2211-36/+36
* 3498Kartik K. Agaram2016-10-141-1/+1
* 3490Kartik K. Agaram2016-10-098-148/+148
* 3489Kartik K. Agaram2016-10-0811-264/+264
* 3457Kartik K. Agaram2016-10-0611-264/+264
* 3445Kartik K. Agaram2016-10-0611-395/+395
* 3429 - standardize Mu scenariosKartik K. Agaram2016-09-2811-814/+883
* 3428Kartik K. Agaram2016-09-281-2/+2
* 3396Kartik K. Agaram2016-09-1712-747/+747
* 3391 - type abbreviations everywhereKartik K. Agaram2016-09-1712-1485/+1485
* 3369Kartik K. Agaram2016-09-151-12/+0
* 3347Kartik K. Agaram2016-09-134-8/+8
* 3341Kartik K. Agaram2016-09-123-4/+4
* 3338Kartik K. Agaram2016-09-124-6/+6
* 3337 - first use of type abbreviations: textKartik K. Agaram2016-09-1212-352/+352
* 3234Kartik K. Agaram2016-08-202-1/+6
* 3233 - change how Mu escapes stringsKartik K. Agaram2016-08-201-4/+3
* 3168 - skip loading recipe 'main' in edit/Kartik K. Agaram2016-08-123-3/+3
* 3101 - purge .traces/ dir from repo historyKartik K. Agaram2016-07-051-4/+0
* 3067Kartik K. Agaram2016-06-255-69/+69
generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-12-22 20:41:48 +0000
t immediate # . op subop mod rm32 base index scale r32 # . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes # Configure an exit-descriptor for a call pushing 'nbytes' bytes of args to # the stack. # Ugly that we need to know the size of args, but so it goes. tailor-exit-descriptor: # ed : (address exit-descriptor), nbytes : int -> <void> # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP # . save registers 50/push-EAX 51/push-ECX # EAX = nbytes 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 0/r32/EAX 0xc/disp8 . # copy *(EBP+12) to EAX # Let X be the value of ESP in the caller, before the call to tailor-exit-descriptor. # The return address for a call in the caller's body will be at: # X-8 if the caller takes 4 bytes of args for the exit-descriptor (add 4 bytes for the return address) # X-12 if the caller takes 8 bytes of args # ..and so on # That's the value we need to return: X-nbytes-4 # # However, we also need to account for the perturbance to ESP caused by the # call to tailor-exit-descriptor. It pushes 8 bytes of args followed by 4 # bytes for the return address and 4 bytes to push EBP above. # So EBP at this point is X-16. # # So the return address for the next call in the caller is: # EBP+8 if the caller takes 4 bytes of args # EBP+4 if the caller takes 8 bytes of args # EBP if the caller takes 12 bytes of args # EBP-4 if the caller takes 16 bytes of args # ..and so on # That's EBP+12-nbytes. # option 1: 6 + 3 bytes #? 2d/subtract 3/mod/direct 0/rm32/EAX . . . . . 8/imm32 # subtract from EAX #? 8d/copy-address 0/mod/indirect 4/rm32/sib 5/base/EBP 0/index/EAX . 0/r32/EAX . . # copy EBP+EAX to EAX # option 2: 2 + 4 bytes f7 3/subop/negate 3/mod/direct 0/rm32/EAX . . . . . . # negate EAX 8d/copy-address 1/mod/*+disp8 4/rm32/sib 5/base/EBP 0/index/EAX . 0/r32/EAX 0xc/disp8 . # copy EBP+EAX+12 to EAX # copy EAX to ed->target 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 1/r32/ECX 8/disp8 . # copy *(EBP+8) to ECX 89/copy 0/mod/indirect 1/rm32/ECX . . . 0/r32/EAX . . # copy EAX to *ECX # initialize ed->value c7 0/subop/copy 1/mod/*+disp8 1/rm32/ECX . . . . 4/disp8 0/imm32 # copy to *(ECX+4) $tailor-exit-descriptor:end: # . restore registers 59/pop-to-ECX 58/pop-to-EAX # . epilog 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP 5d/pop-to-EBP c3/return stop: # ed : (address exit-descriptor), value : int # no prolog; one way or another, we're going to clobber registers # EAX = ed 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX 4/disp8 . # copy *(ESP+4) to EAX # if (ed->target == 0) really exit 81 7/subop/compare 0/mod/indirect 0/rm32/EAX . . . . . 0/imm32 # compare *EAX 75/jump-if-not-equal $stop:fake/disp8 # . syscall(exit, value) 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 3/r32/EBX 8/disp8 . # copy *(ESP+8) to EBX b8/copy-to-EAX 1/imm32/exit cd/syscall 0x80/imm8 $stop:fake: # otherwise: # ed->value = value+1 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 1/r32/ECX 8/disp8 . # copy *(ESP+8) to ECX 41/increment-ECX 89/copy 1/mod/*+disp8 0/rm32/EAX . . . 1/r32/ECX 4/disp8 . # copy ECX to *(EAX+4) # perform a non-local jump to ed->target 8b/copy 0/mod/indirect 0/rm32/EAX . . . 4/r32/ESP . . # copy *EAX to ESP $stop:end: c3/return # doesn't return to caller test-stop-skips-returns-on-exit: # This looks like the standard prolog, but is here for different reasons. # A function calling 'stop' can't rely on EBP persisting past the call. # # Use EBP here as a stable base to refer to locals and arguments from in the # presence of push/pop/call instructions. # *Don't* use EBP as a way to restore ESP. 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP # Make room for an exit descriptor on the stack. That's almost always the # right place for it, available only as long as it's legal to use. Once this # containing function returns we'll need a new exit descriptor. # var ed/EAX : (address exit-descriptor) 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP 89/copy 3/mod/direct 0/rm32/EAX . . . 4/r32/ESP . . # copy ESP to EAX # Size the exit-descriptor precisely for the next call below, to _test-stop-1. # tailor-exit-descriptor(ed, 4) # . . push args 68/push 4/imm32/nbytes-of-args-for-_test-stop-1 50/push-EAX # . . call e8/call tailor-exit-descriptor/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP # call/ed(ed) _test-stop-1(ed) # w/exit(ed) _test-stop-1(ed) # . _test-stop-1(ed) # . . push args 50/push-EAX # . . call e8/call _test-stop-1/disp32 # registers except ESP may be clobbered at this point # restore args 58/pop-to-EAX # check that _test-stop-1 tried to call exit(1) # check-ints-equal(ed->value, 2, msg) # i.e. stop was called with value 1 # . . push args 68/push "F - test-stop-skips-returns-on-exit"/imm32 68/push 2/imm32 # . . push ed->value ff 6/subop/push 1/mod/*+disp8 0/rm32/EAX . . . . 4/disp8 . # push *(EAX+4) # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP # . epilog # don't restore ESP from EBP; manually reclaim locals 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP 5d/pop-to-EBP c3/return _test-stop-1: # ed : (address exit-descriptor) # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP # _test-stop-2(ed) # . . push args ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) # . . call e8/call _test-stop-2/disp32 # should never get past this point $_test-stop-1:dead-end: # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP # signal test failed: check-ints-equal(1, 0, msg) # . . push args 68/push "F - test-stop-skips-returns-on-exit"/imm32 68/push 0/imm32 68/push 1/imm32 # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP # . epilog 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP 5d/pop-to-EBP c3/return _test-stop-2: # ed : (address exit-descriptor) # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP # . stop(ed, 1) # . . push args 68/push 1/imm32 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) # . . call e8/call stop/disp32 # should never get past this point $_test-stop-2:dead-end: # . epilog 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP 5d/pop-to-EBP c3/return # . . vim:nowrap:textwidth=0
generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-12-22 20:41:47 +0000