Masm push model flat,stdcall CREATE/OPEN push NULL push FILE_ATTRIBUTE_NORMAL push OPEN_EXISTING push NULL push 0 push GENERIC_READ push offset FileNameFrom call CreateFile ;-----; ;or push str+4 is valid NASM syntax and will assemble to what you want: push imm32 with the absolute address as the immediate (or in the . Otherwise those 24 bytes are the bottom of the shadow space the called function I finally was able to fix it in XP mode by changing a push/pop to eax instead of ax. The MASM Forum Archive 2004 to 2012; General Forums; The Campus; USES versus PUSH for register preservation; USES versus PUSH for register preservation. The stack (esp/rsp should be the same value, as before push 0, as the GetProcAddress should restore it (remove arguments from stack), that's how stdcall is defined). News: Masm32 SDK description, downloads and other helpful links One more thing, try and avoid using PUSH POP as they change the RSP register. Вот пример:. Passing string parameter to a PROC. Previous topic - Next 2005, 09:25:27 AM by pmpnfrsh Hey ppl I am fairly new to MASM, and i am trying to re-write the "hello world" application using PUSH/POP parameters rather than invoke. However, this prevents . push 0 ret abc ENDP END abc 4. call mystruct. AX is the lower word of EAX, then you push it 16 bits to the left (SHL), now the upper word is no longer in AX, now it is in the upper word of EAX. January 10, 2025, 09:55:47 PM. Explain Push and Pop Loop. If you don't want to rely on USES, you'll need to preserve the registers that you want to keep or that need preserving. Ratch The video comprehensively explains the Stack Data Structure, its core concepts and also explains the Push and Pop operations on Stack. Using LEA to get the address into a register is only useful in position-independent x86-64 code since LEA can use RIP-relative addressing. With two words in EAX, you can move the value from EAX to any variable. exe or ml64. ExitProcess By hitting F7 in Olly, you can dig inside StdOut to see this: push ebp mov ebp, esp add esp, -0C push -0B call GetStdHandle ; jmp to kernel32. I'm trying divide two numbers in assembly. Синтаксис. This works for IA-32 because its pop doesn't just pop the stack, it also delivers the value it pops. As I don't know which directive to toggle to get it to recognize it, I just left it for now :lol. PUSH / CALL syntax is relatively simple on win 32 using STDCALL but from the specs I have read recently for Win 64 the version of FASTCALL is somewhat more complicated and while the more experienced Microsoft Macro Assembler (MASM) [перевод] ЮРИДИЧЕСКИЙ ОТКАЗ ОТ ОТВЕТСТВЕННОСТИ: Все ссылки на продукты Microsoft, включая: Microsoft Macro Assembler (MASM), MS-DOS, Visual C++, Visual Basic, Visual Studio, Windows, Windows NT, Windows Software Development Kit (SDK) и связанные с ними продукты NASM. , ml. Started by Nyatta, January 23, 2016, 08:38:32 AM. Share. mov cl, 4 ; Rotate register 4 bits. IF largestVal < ebx from working. Основы ассемблера MASM для Intel x86-64. The MASM notation ADDR is an abstraction of an address which can be either an OFFSET or a dynamically created memory location on the stack, normally called a LOCAL variable. code mai proc push rbp push rsp mov ecx,3 call writei pop rsp pop rbp ret mai endp end c++; visual-c++; masm; Share. MASM: How to pass value by reference. printf) from a 0Ah is the backslash - escapes are not supported . If the ESP or SP register is 1 when the PUSH instruction is executed in real-address mode, Использование 32-разрядных инструкций push/pop в режиме x64 Assembler, MASM Решение и ответ на вопрос 2609347 операции jmp/call и push/pop с 32-битными регистрами-операндами невозможны, In this article. What I mean is that when you're promming in assembly for Windows you don't need to use registers to "invoke" the APIs, you have to push the arguments and then call (or invoke) the API. FAQ для раздела Assembler, MASM, TASM Assembler Решение и ответ на вопрос 883314 15A3:0100 57 PUSH DI 15A3:0101 69 DB 69 15A3:0102 6E DB 6E 15A3:0103 64 DB 64 15A3:0104 30795A XOR [BX+DI+5A] ,BH 15A3:0107 206D75 AND [DI+75 printf working not correct in masm. LISTALL DISPE PROC NEAR MOV EBX, 10 PUSH BX MOV CL, 0 I am trying to pass 3 parameters to a procedure, add them, and return them in tax register in MASM. Later, in the video, I push 2 push 4 push 6 push 8 push 10 Then the first value popped off the stack is 10, then 8, then 6, etc. How to push and pop from a stack in Assembly mips? 2. MASM uses the standard Intel syntax for writing x86 assembly code. Currently I'm running DOSBOX on Windows 8 64-bit. This question already has an answer here: Assembly x86 division with DX:AX (1 answer) Closed 8 What is perfectly possible is to push all the arguments that an API call requires and then you just call the desired function. UsedBytes mov ch,dl mov si,offset InpBuf. 386 . Member; I have to write code that is supposed to read the text from a . SH Codez SH Codez. CODE main PROC mov eax, 76313 push eax push offset fmt call crt_printf sub esp, 8 MASM assembly - REAL4 float instructions. When you use ADDR in invoke, if will usually just push the address if it can, if not then it will do "LEA eax,[whatever]" and "PUSH eax" Hope that clears it Writing x64 Assembly code using MASM, we can use these directives to provide frame unwinding information. November 27, 2024, 02:43:37 PM. call @F db 'lol',0 @@: That's how you'd do it in MASM, not sure of the exact syntax for inline assembly. isPrime PROC push Some flags can be set or cleared directly with specific instructions: CLC, STC, and CMC: clear, set, and complement the carry flag; CLI and STI: clear and set the interrupt flag (which should be done atomically); CLD and STD: clear and set the direction flag; For reading and writing the sign, zero, auxiliary carry, parity, and carry flags, you can use LAHF to load the Where I can find good tutorial for masm 64 bit? extrn printf : proc . News: Masm32 SDK description, downloads and other helpful links Message to All Guests NB: Posting URL's See here: Posted URL Change. В нем есть стандартные функции push и pop. ) This matches the "stack width" of call/ret. asm) . inc include c:\masm32\include\kernel32. Invoke is a macro that pushes the parameters onto the stack (in STDCALL or reverse order) and executes a call. I can send you a code snippet if you are really interested. When i define a function, then after disassembling i see that at the beginning of my function: push ebp mov ebp,esp How can i avoid this ? I want to program the stack by myself. News: Masm32 SDK description, downloads and other helpful links push 0 mov eax, offset MyTitle push eax mov eax, offset MyText push eax push 0 call MessageBoxA;push eax call ExitProcess end start push 00h push 63h pushw 6578h push 456e6957h mov [ebp-4], esp Characteristically MASM does the exit with a LEAVE instruction which is a bit different from many compilers but it works fine. asm 1 bits 64 2 3 push byte 0x21 4 push byte 0x4321 5 6 push word 0x4321 7 push word 0x654321 8 9 push qword 0x654321 10 11 push 0x21 12 push 0x4321 13 push 0x654321 14 push 0x87654321 15 push 0xa987654321 16 # nasm -v Masm code translated into Nasm code. They changed the meaning of some of the opcodes to those new instructions. Started by pmpnfrsh, February 06, 2005, 03:49:41 AM. push eax ; store bitmap size at ESP+4 (see next push) mov eax, maxx ; load length of row The stack for PUSH / POP work on a last on, first off basis so the POPs must be in reverse order to the PUSHs. Generates a UWOP_PUSH_MACHFRAME unwind code entry. push, pop, movs). January 05, 2025, 10:40:36 PM. AMD needed some room to add new opcodes for REX prefixes and some other new instructions when they developed the 64-bit x86 extensions. Viewed 13k times 0 . Ask Question Asked 10 years, 7 months ago. Member; Posts: 87; Logged; Re: Succesive Writes vs PUSHes #1. January 07, 2025, 10:35:03 AM. So label is an address, and so is 0x123. Welcome to The MASM Forum. Could anyone give me an idea?I am working in masm. News: Masm32 SDK description, downloads and other helpful links freg_push eax mov eax, 2264 freg_pop eax conout str$(eax),lf,lf ret other endp. Without the push and pop, it will print out 'Hello World' infinite ! Looks like I go an infinite loop going in MASM x86! I think I need some help understanding what exactly is going on. It is simply a convenient shorthand so Retrieve arguments of a x64 masm assembly procedure. nexthex: push dx ; Save the loop counter. Viewed 20k times 11 . hInstance Can someone explain to me what they do and if there is another way to do whatever is done by them using another instruction. DATA fmt db "%d",10,0 . In particular, I'm trying to do a very simple DOS-like OS, I have several segments defined like this; The PUSH immediate instruction was introduced to the x86 architecture with the 80186. 8BB424 A0010000 mov esi, [esp+1A0] 00401351 ³. Сложение и вычитание In this video I demonstrate the use of the PUSH and POP instructions to work with the Stack in MASM Assembly. You have to get a couple of things right, correctly align the stack and write the arguments according to x64 FASTCALL calling convention. Values in other registers are preserved only when stdcall defines that for particular register, otherwise the code is free to change them ( eax, ecx, edx are volatile, if I'm reading the wiki DONE: PUSH DS MOV AX,0 PUSH AX RET START ENDP;MESSAGE IAMHERE PROC PUSH AX PUSH DX MOV AH,9 MOV DX, OFFSET LOGO INT 21H ;----print command line string mov ah,9 mov dx,offset data int 21h POP DX POP AX IAMHERE ENDP COMSEG ENDS END START I have split this topic where it shifted from the 64 bit MASM project into wider and different topics. This directive is from the MASM syntax where "push variable" means push the value of the variable and "push offset variable" means push but in memory, the segment base is added to the offset to produce just one address. There is no single instruction capable of taking a 64-bit Функции pop и push Здравствуйте, есть код, решающий задачу. assembly-time evaluation of floating-point expressions. com New Forum Link masmforum WebSite. I don't know MASM, but I assume that GetNumLetters PROC, arrayInput: PTR BYTE, arrayCount: PTR BYTE, arrayLength: BYTE generates some prologue for you, or defines those names as an offset from EBP that assumes you set up your stack If its MASM x64, it does not use PUSH / CALL syntax. 2. e. News: push eax lea eax, format push eax call printf xor eax, eax push eax call ExitProcess main ENDP END main - I was debug and saw variable named "something", its value is correct. Ask Question Asked 8 years, 6 months ago. 14 Во втором семестре первого курса освоение языка Ассемблера может выполняться в среде виртуальной машины 2. Remarks. So i'm attempting to make the game of Tik Tak Toe in MASM 32 bit but I cannot figure out how to pass a string from MASM to C++ to output text to the console. Improve this answer. I am trying to return the number after some operations, but compiler returns push esp, push num, pop esp, pop num invalid instruction operands, although MASM allows push {register}. Besides, if you use SIMD instructions like movaps with local variables, How would we do this in Masm if we had to? (example from MSDN) Code Select Expand // Total size = 24 bytes, alignment = 8 bytes (quadword). Finally, you assign the lower word to AX. Первая программа на MASM. Posted on 2008-09-18 22:24:06 by sinsi. Decrements the stack pointer by 4 (if the current operand-size attribute is 32) and pushes the entire contents of the EFLAGS register onto the stack, or decrements the stack pointer by 2 (if the operand-size attribute is 16) and pushes the lower 16 bits of the EFLAGS register (that is, the FLAGS register) onto the stack. July 15, 2024, 08:22:58 AM. code _main PROC push 8 push 3 call greater call Crlf mov edx, OFFSET PorukaZaIspis call If a PUSH instruction uses a memory operand in which the ESP register is used for computing the operand address, the address of the operand is computed before the ESP register is decremented. The program almost never pushed a variable to the stack. If you have absolute references like this within bootseg: mov al, If you post a snippet you may miss the important bits and we can't know whats wrong of course. This does not appear to happen when largestVal is defined as a DWORD. ref1: According to jmalak, the first STACK w/o quotation marks attaches a STACK combine type attritute to stk segment, while the second 'STACK' w/ quotation marks attaches a class push offset menss call crt_printf push offset salvar ;push salvar push offset saida call crt_scanf mov eax,offset salvar push eax push offset saida2 call crt_printf; invoke crt_printf,addr saida2,salvar push 0 call ExitProcess end start I want to digit a number, and my program will print this number. Viewed 343 times 0 . The MASM Forum Archive 2004 to 2012; Project Support Forums; GoAsm Assembler and Tools (Moderators: donkey, jorgon) 64 BIT PUSHAD; Logged; 64 BIT PUSHAD. 8B9C24 A4010000 mov ebx, [esp+1A4] 00401358 ³. Several of the Welcome to The MASM Forum. The PROTO directive is only used in MASM,there are no other assemblers that use it as far as I know, in MASM it is only necessary for forward referenced procedures or external ones. This video shows how to push and pop registers There are several different assembly languages for generating x86 machine code. Generates a UWOP_PUSH_NONVOL unwind code entry for the specified register number using the current offset in the prologue. We can get rid Assembly Language MASM jumping. Conceptually, AT&T syntax treats everything as a potential address. hutch--In Welcome to The MASM Forum. esp can now wander for push/pops inside callee. Глава 2. News: Masm32 SDK description, downloads and other helpful links Message to All Guests Intel Reference Manual doesn't mention anything about direction flag for push I I use masm with RadASM. 02rc7, с официального сайта, которой проводилась сборка 20й версии в For global variables ADDR operator translates to a simple PUSH instruction, just as if OFFSET had been used: push GlobalVar However, for local variables ADDR translates to: lea eax, LocalVar ; load effective address of LocalVar into eax push eax Effective address is the physical address of the data in memory. 56 push esi 00401343 ³. Modified 10 years, 7 maxchar, minchar, x,y LOCAL READ_DATA,COPY_DATA pushf push ax push bx push cx push dx push si mov ah,02h ;position cursor at x,y. retn otherwise the stackeframe will not be automatically destroyed as MASM also generates the epilogue in this case. I'm working out of the Irvine assembly for intel computers book and I can't make division work for the life of me. SETFRAME definition: 04: SET_FPREG, register=rbp, offset=0x00 01: PUSH_NONVOL, register=rbp A bit of explanation to the output: The second hex number found in the output is the function address 00001530 so I'm trying to learn assembly language using masm and doing some practice coding and im wondering what's wrong with my code . PUSHREG register. 1 2 2 bronze badges. but at the moment you're pushing values of 10 and 20 onto the stack and not the addresses (ByRef) of these variables. How can I do this in masm? call version push . Modified 7 years, 7 months ago. Follow answered Dec 9, 2019 at 0:51. This is what i did: key dq 0 give_key db "Enter the encryption key (64-bit): " , 0 formatkey DB "%lld ", 0 procedure PROC NEAR push offset give_key call printf add esp,4 push offset key push offset formatkey call scanf add esp,8 ret procedure ENDP assembly; masm; Share. For example if I try and write a 55 instead of push ebp ML thinks it is an integer. Push a string onto the stack. caller: subroutine called, return address pushed (call does that, no code needed) 3. June 13, 2017, 01:53:33 PM. Viewed 1k times NEAR, PutHex : NEAR Main PROC _Begin push 10 push 20 call Test12 ; Print result call PutDDec _Exit Main ENDP Test12 PROC push ebp mov ebp, esp mov eax, [ebp+12] ; When we use pop, from what I understand is kind of like using free() in C. code _start: mov eax, 100 Hans is correct Invoke doesn't understand how to pass a struct by value. model flat,stdcall include c:\masm32\include\msvcrt. What's wrong? PUBLIC from_asm EXTERN puts:PROC EXTERN exit:PROC . There is absolutely no advantage to using push instead of uses, The MASM Forum Archive 2004 to 2012; General Forums; The Campus; push/pop; push/pop. Main Menu Home; The MASM Forum General The Campus Push a string onto the stack; Push a string onto the stack. I have modified the topic title to make this distinction. assume cs:cds,ss:stk stk segment STACK 'STACK' dw 32 dup(0) stk ends cds segment main: mov ax,4c00h int 21h cds ends end main Synopsis(Official MASM reference). Not that you need to worry about any of this too much, since it's mostly hidden by the masm syntax, but it's detail if you want it ;) Quote from: jack on September 27, 2024, 12:41:56 PMa web search gave this How to Use MASM in Visual Studio 2022 it's a bit late for me but I plan on trying it out tomorrow That wiki is for using VS and MASM (the assembler, i. Log in; Sign up; The MASM Forum. Внезапно оказалось что в Node. PUSHAD and POPAD are useful for performing a easy save and restore of the general purpose registers without having to PUSH and POP every individual register in turn. January 13, 2025, 10:45:06 PM. How many bytes does the push instruction push onto the stack when I don't specify the operand size? Graphics - Bresenham's Line Drawing Algorithm, in MASM. I'm new to assembly language. data PorukaZaIspis db "Poruka za ispis", 0 . Buffer mov ah,dl PrInp1: lodsb xor al,30h cmp al,9 ja PrInp2 cmp dx,6553 ja PrInp4 shl dx,1 mov bx,dx isPrime PROC USES ECX EBX Although this claims to be using EBX, the code actually uses ESI and doesn't even touch EBX. data num dd ? # cat -n push. UWOP_PUSH_NONVOL (0) 1 node. what is TYPE DWORD, is that Pushing a 64 bit register (64 is a multiple of 16) keeps the stack aligned to 16 bit (10h), so it shouldn´t make problems, but as the code demonstrates - it does! Pushing two 64 PUSH immediate on the AMD64 takes a 32-bit immediate (number) value and sign extends bit 31 into all higher bits. If ehandler is present, this proc is entered in In this article. June 21, 2024, 07:30:55 PM. Hot Network Questions How to design a network and loss function for classes, composed of two other classes? Where did Sofia Kovalevskaya compare being a mathematician to being a poet? masm division overflow. somefunction strangely the problem with this is that my pushes will not push members of my struct! IE: push mystruct. The Overflow Blog “Data is the key”: Twilio’s Head of R&D on the need for good data push [chr] is ambigous. User actions. Modified 8 years, 6 months ago. When you use the built in MACRO "invoke" it automates the TITLE MASM Template (main. The questions are the following: 1. model FLAT . Here's my code. push [var] — push the 4 bytes at address var onto the stack. MASM uses the standard PUSHAD pushes all of the 32-bit general-purpose registers on the stack in the following order: EAX, ECX, EDX, EBX, ESP (value before executing PUSHAD), EBP, ESI, and EDI. I am writing some SSE2 scalar math functions going 64 ABI if I use xmm0 as input register ,whats best standard return result register to use? ; Displayed Annotation for Unsorted Array unsortedArrayText byte "Randomly Generated Array, Unsorted: ", 0dh, 0ah, 0 ; Displayed Annotation for Sorted Array sortedArrayText byte "Randomly Generated Array, Sorted from Lowest to Highest: ", 0dh, 0ah, 0 . This video shows how to push and pop registers An OFFSET in MASM is a location (literally an OFFSET) When you use ADDR with a local variable ADDR (through INVOKE) create the following code : LEA AX,MYVAR ; PUSH EAX If it is on a global variable, into the DS segment, the ADDR becomes PUSH OFFSET MYVAR You can MOV EAX,OFFSET MYVAR but not MOV EAX,ADDR MYVAR Division in assembly - MASM [duplicate] Ask Question Asked 8 years, 8 months ago. push . btw: i am new to assembler. For now I want to be able to read 64-byte blocks and write them without any change to the destination file. inc includelib c:\masm32\lib\msvcrt. 586. com . data Ten DD 10 Twenty DD 20 The MASM Forum General The Campus push 0; push 0. When a CALL is made, you need to have pushed the arguments onto the stack first. js есть вставки на чистом ассемблере, поэтому для сборки нужно установить NASM. Syntax. data if the address of Команды push и pop - это основные команды для работы со стеком. Otherwise the modifier is 0. lib includelib c:\masm32\lib\kernel32. ; Notice that the parameters are passed in registers rather than being pushed on the stack in reverse order. What happens exactly under the hood to Assembly `push`, `pop`, `call`, You can push or pop with a memory operand directly instead of bouncing through RAX, like push qword [some_float]. When the variable is a LOCAL created on the stack, the underlying code uses LEA to get the effective address of that variable. and al, 0Fh ; Mask off all but 4 lowest bits. Started by afueikawa, September 12, 2014, 12:59:08 AM. 1234: 1234AA Now you use e. January 12, 2025, 10:22:54 PM. txt file. Gunther. https://masm32. jj2007. It's runing on x64, MASM, with Visual Studio (Debug mode x64). model flat, stdcall . Re: LOCAL variables in masm. The value of SP is the value before the actual push of SP. I also changed from MFENCE to CPUID as MASM did not recognize the former. On the other hand MSVC handles well the situation, it does not makes 2 pushes totaling 8 bytes, it reserves 4 bytes in the stack through "sub esp" and puts the structure there by moving 1 byte more 1 word. I use "MASM" to "DOSBOX" and already made seven successful programs, I only need the latter but can not find my mistake. – mov dx, 4 ; Loop will print out 4 hex characters. pop x does the opposite: copies the top of the stack into x, and then moves the stack Timings for bswap, ror, imul, push+pop vs mov [esp+x], nnn, lodsd vs mov eax,. The first method stores the "lol" string in the data section of the exe, whereas the inline version stores it in the code section. Improve this I will try and answer some of the questions that would be of use to a development team based on both using and supporting MASM for many years now. But when I compile and run it: C:\masm32 Segment: _TEXT DWORD USE32 00000033 bytes 0000 _main: 0000 55 push ebp 0001 8B EC mov ebp,esp 0003 83 EC 10 sub esp,0x00000010 0006 C7 45 F0 01 00 00 00 mov dword ptr -0x10[ebp],0x00000001 000D C7 45 F4 02 00 00 00 mov dword ptr -0xc[ebp],0x00000002 0014 C7 45 F8 03 00 00 00 mov dword ptr -0x8[ebp],0x00000003 001B push NULL mov ecx,esp push NULL push ecx ; ecx -> lpNumberOfBytesWritten push eax push OFFSET buffer invoke GetStdHandle,STD_OUTPUT_HANDLE push eax call WriteFile mov eax,DWORD PTR [esp] pop ecx mov DWORD PTR [esp],esi mov esi,_esi IFDEF __POASM__ retn ELSE ret ENDIF printf ENDP OPTION PROLOGUE:PROLOGUEDEF "Pushes all general purpose registers onto the stack in the following order: (E)AX, (E)CX, (E)DX, (E)BX, (E)SP, (E)BP, (E)SI, (E)DI. When you want a number as an immediate operand, you use add $0x123, %eax. Previous topic - Next topic. exe пользователям указывать способ очистки функции Push EAX Push ECX Push EDX Push EBX Push ESP Push EBP Push ESI Push EDI POPAD pops the values back off the stack in reverse order, thus restoring all the register values. For example, this: using MASM 8086 program determines the largest value in the given arrays Unhandled exception gets thrown when esi is increased. – Jerry Coffin. push sizeof_image;a4-buffer ;nNumberOfBytesToWrite=97 push push ax push bx push cx push si PrInp0: push dx mov ah,9 int 21h mov dx,offset InpBuf mov ah,0Ah int 21h call NewLine xor dx,dx mov cl,InpBuf. Using a symbol address as an immediate operand works identically. The Standard Template Library for C++ has a pop that just manipulates the stack and you need a different command to access the top of the stack Understanding The Shortest Valid x86 MASM Assembly Program. Understanding assembly data I think MASM allows quoted constants for db, so that should get it to assemble. Я использовал последнюю (уже нет) версию 2. The AT attribute gives you the segment part of the address we want to jump to. Instruction Order Welcome to The MASM Forum. Print. eg. stack 4096 . dll - Access violation reading location 0xFFFFFFFFFFFFFFFF. Инструктивно-справочные материалы по практикуму на masm 6. I tried to use google and other documentation and they explained very well what the push and pop instructions do, but I can't fit my understanding of them in the context of this program. lib . MODEL TINY . Позволяют заносить значения регистров и ячеек памяти в стек и извлекать их оттуда. So 10 will get printed first. I'm trying to push a 64bit integer but when assembling NASM seems to want to see it as a DWORD not a QWORD. FPU in a trice: SmplMath It's that simple! ragdog. 81EC 8C010000 sub esp, 18C 0040134A ³. model flat then you will eliminate the "long jump" problem. Modified 4 years ago. eg:;array1 BYTE 256 DUP(?) lea edi, array1 push 256/4 xor eax, eax rep stosd 3 Welcome to The MASM Forum. - in 32-bit code, you can misalign stack by pushing a word instead of a dword: try push ax before invoking a MessageBox. This is not always the case. There is indeed a bug in MASM when using invoke with the 3 byte structure. It seems to me to be more efficient, and that is the name of the game with MASM isn't it. Started by 00100b, January 11, 2005, 12:09:44 PM. Ask Question Asked 4 years ago. You're probably also breaking MASM's attempts to help you by doing other pushes before push ebp / mov ebp, esp. In the case of COORD you can cast it to a DWORD as a parameter to Invoke. 0. Что не так важно в In this video I demonstrate the use of the PUSH and POP instructions to work with the Stack in MASM Assembly. 16. Code Select Expand. Push A, Push B, Pop to A, Pop to B. if I in the subroutine registers not save with push then does not work the routine my ask was if I with register work must I always the registers save with push Ассемблер MASM. pop — Pop stack I want to get started in MASM in a mixed C++/Assembly way. Как можно Работа с push/pop в стеке В этом руководстве раскрывается тема создания, использования (а главное – проектирования) макросов и макрофункций в проектах на MASM32. 55 push ebp 00401341 ³. If you place the segment inside it should work with both MASM and TASM assemblers as well as the open source JWASM assembler as well. exe), NOT either the Masm32 SDK or Masm64 SDK. Does x86 have a "jump and link"? Sounds like your installation of masm is probably munged -- didn't crash for me at all (and did point out some errors in your code, such as lack of size specified on a couple of pushes, and the fact that ebpi (obviously intended to be ebp) and base_case are undefined symbols. mov sum, firstparam is simply incorrect because there's no such form of mov. News: Masm32 SDK description, downloads and other helpful much slower than 6 successive PUSHes. how can I pass 10 arguments in MIPS? 1. push ADDR pOldProtect since it is a pointer to a dword whereas your code pushes the dword, which could be anything. callee: ebp pushed (caller ebp backed up) ; i'd rather do this before step1 to keep params/ret closer aligned to ebp inside callee 4. Main Menu Home; Search; January 09, 2025, 05:26:29 AM. For example, from . code Установка MASM. push offset msg1 ; put in to stack the effective add of msg1 call StdOut ; I'm writing a multi-modular assembly project with MASM for DOS. If your memory operand includes a register and an offset then MASM will not complain, so this is valid MASM syntax: I'm getting confused on what does pop actually do in assembly. Because your code has multiple ret instructions, you also need multiple restoration sequences:. code foo PROC x:DWORD, y:DWORD mov eax, x mov ebx, y add eax, ebx push eax mov eax, x mul ebx push eax push OFFSET tstStr call printf ret I've come across some odd behaviour when attempting to use local variables using masm. I'm using ASM to create the shellcode I need to inject a 64bit DLL into a 64bit process. Keep in mind also, that if you let masm set up the stackframe for you, you must use ret and not i. I had a folder 8086 that contains DEBUG, BIN2HEX, EDIT, EXE2BIN, LINK, MASM, 0 MsgTitle db "Our First MessageBox", 0 . And then we have multiple other bugs at runtime: Also, you need to sub rsp, 32to reserve shadow space after pushing 3 registers, if you want to restore them after. Member; Posts: 3,851; push 185C8h ;----- _size push offset dword_40A270 ;-----My_file push GetProcAddress there is no equivalent to fasm's load and store directives in masm. This should work:. January 12, 2025, 02:16:48 AM. lea rcx, [fmtString] mov rdx, [valueForPrintf] mov r8, [value2ForPrintf] call printf push hInstance pop wc. The first QWORD is the old instruction pointer, MASM: How to pass value by reference. g. push 0 call ExitProcess ; jmp to kernel32. Note that MASM does quite a bit of checks for you. Для работы с MASM надо установить для Visual Studio инструменты разработки для C/C++. Specify a processor to enable the long Jcc jumps. Команда push The default operand-size for push in AT&T syntax (and in all other assemblers, like NASM and MASM) is the width of the current mode. Ask Question Asked 11 years, 1 month ago. It can be found in the 64 bit assembler forum for any who wish to contribute to that discussion. Started by Timofeyka, July 09, 2021, 06:30:02 PM. I have a function in c++ which is called writei, proto . Go Down Pages 1 2. rol ax, cl push ax ; Save current value in AX. PUSHFRAME allows ml64. Установщик для среды Visual Studio можно загрузить по следующему адресу: Microsoft Visual Pass parameters by adress to Macros in Assembly 8086 MASM. ebp becomes stack base for callee. code main PROC ; Get Random Values for Array call fillArrayRandomly ; Display Array with I'm making a simple message program using MASM. mov bh,0 mov dl,x mov dh,y int 10h mov al,maxchar Turn it into MASM, makeArray PROC push ebp mov ebp, esp sub esp, 32 lea esi, [ebp-30] mov ecx, 30 L1: mov BYTE PTR [esi], '*' inc esi loop L1 add esp, 32 pop ebp ret makeArray ENDP Question: Can I write mov esi, ebp-30 instead of lea Pushing strings to C++ from MASM. Does pop move the value PUSHed onto the stack last (meaning it doesn't apply if we MOV a value after the the last element PUSHed) or does it just pop whatever value that's last on the stack (thus, applying to both MOV and PUSH), or does it pop what ever value pointed to by the stack pointer? Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Yey! :bg Properly popping and pushing esp solves everything :D. Modified 8 years, 8 months ago. COORD is 2 16-bit values which happens to be the size of a DWORD. o object file, the same relocation as would be used for the disp32 in lea reg, [symbo+4]). Any help would be Is there a way to write a program using pure x86 intel opcodes instead of the assembly mnemonics and instructions and then compile it with ML and LINK. Pause Before Exit. 3. This for i:=10 to 20 do 9716:0061 c70652000a00 mov [0052],000a 9716:0067 eb04 jmp 006d 9716:0069 ff065200 inc w/[0052] write(a[i]:4); 9716:006d bf6c01 mov di,016c 9716:0070 1e push ds 9716:0071 57 push di 9716:0072 8b3e5200 mov di,[0052] 9716:0076 d1e7 shl di,1 9716:0078 8b854200 mov ax,[0042+di] 9716:007c 99 cwd 9716:007d 52 push dx 9716:007e The MASM Forum General The Campus Which registers are safe, control questions; Which registers are safe, control questions. PUSHFRAME CODE ;;. Instead of push push push call MyTest, you should use invoke MyTest, arg1, arg2, arg3. Immediate value as an operand for push instruction without a size operator results by default into pushing 16 bits if assembler is in 16-bit mode and 32 bits if assembler is in 32-bit mode, shorter 8-bit form of this instruction is used if possible, word or dword size operator forces the push instruction to be generated in longer form for specified size and also push this size. Other assemblers, such as NASM and FASM, use syntax different from MASM, similar only in that they all use Intel syntax. ArraySum PROC push esi ; save esi, ecx push ecx mov eax, 0 ; set the sum to zero L1: add eax, [esi] ; add each integer to sum add esi, TYPE DWORD ; point to next integer loop L1 ; repeat for array size pop ecx ; restore ecx and esi to original values pop esi ret ; sum is eax ArraySum ENDP PUSHes use less memory than MOV's, and I suspect they might be faster too. It moved the value of the variable to a register and then pushed the register. 53 push ebx 00401344 ³. GetStdHandle mov [ebp-4], eax push dword ptr [ebp+8] call StrLen mov [ebp-C], eax push 0 lea eax, [ebp-8] push eax OK, since you are already looking at disassemblies, here a little test case showing essential features of MASM, like arguments and the "uses" way to preserve the non-volatile registers esi edi ebx (->more). stack 4096 WriteString PROTO stdcall ReadChar PROTO stdcall Crlf PROTO stdcall ExitProcess PROTO stdcall:DWORD greater PROTO C :DWORD, :DWORD . But of course this particular example is silly, you'd just fld qword [some_float] . If your first two lines are. Member push rdi sub rsp, 40h mov rdi, rsp ; Before calling printf, pass the format string in RCX, and int values in RDX and R8. Определение данных и их типы. Hey there guys, Just playing around with PUSH instruction and noticed from the AMD reference that PUSHAD is not supported anymore, i did some googling to find that I cant just use floating point values like that with push and mov etc, at least in masm however people have mentioned some workarounds and talk for FP values larger than a DWORD you need to manipulate the individual components, and indicate to MASM what you wish to do. Push also stores things on the stack, but what happens when you enter a 'proc' is "mov ebp,esp" and then any modifications to esp don't mess you up on referencing variables through ebp. code start: mov eax,0 push eax lea ebx , MsgTitle This page will explain x86 Programming using MASM syntax, and will also discuss how to use the macro capabilities of MASM. The push 0 creates a variable: AAAAA stack before 0000AA stack after push 0 The function uses these 4 bytes to store a result, e. I even tried pushing individual parameters instead of using invoke for SetFilePointer. Causes MASM to generate a function table entry in . A quick&dirty alternative: load first four arguments to their registers, align RSP and then PUSH Sixth, Fifth, R9, R8, RDX, RCX before CALL. So how does PUSH OFFSET somevariablehere come to pushing the offset of "Hello World" in . (16 bits in 16-bit mode, 32 bits in 32-bit mode, 64 bits in 64-bit mode. callee: esp copied to ebp. However, the result is off with a PutHex : NEAR Main PROC _Begin push 10 push 20 push 30 call Test1 call PutDDec add esp, 12 _Exit Main ENDP Test1 PROC ; *** Standard subroutine prologue *** push ebp mov Можно воспользоваться функцией printf из msvcrt. sorry, i thought I was on 64-bit. News: Masm32 SDK description, downloads and other helpful links For me, it's a mystery that push 8, pop eax can be as fast as mov eax, 8, because the former instruction requires two memory accesses. kc ats eht ot d essa p si gni rts sihT push 27491 push 1635021600 push push esi mov esi, 5 lbl: ; run code here sub esi, 1 jnz lbl MASM 6 defaults to assembling only 8086/8088 code. add rsp, 16 ;2* 64bit value ret printData endp end Or push the address on the stack and use a far RET instruction to "return" to it: push 0ffffh push 0 retf But is MASM's default object file format, PECOFF, doesn't support this. Accessing parameters in Assembly. instead of. ;hInst:DWORD 4 lea esi, hInst push esi 2. dll. Also, the normal INVOKE can sub rsp, 40h push 0 push FILE_ATTRIBUTE_NORMAL push CREATE_ALWAYS xor r8, r8 xor r9, r9 mov rdx, GENERIC_READ or GENERIC_WRITE mov rcx, Arguments to function not getting passed in correctly MASM. But there is one big difference. exe users to specify how a frame function unwinds, and is only allowed within the prologue, which extends from the PROC FRAME declaration to the Description ¶ . UWOP_PUSH_NONVOL Создает запись кода очистки для указанного регистра с помощью текущего смещения в прологе. December 03, 2024, 07:33:40 PM. That doesn't mean that there's some hard rule that says that an instruction can't both read and write memory - it's just that there aren't that many such instructions, and the ones that exist usually have an implicit source and/or destination (e. So add 0x123, %eax loads from the address 0x123, and add label, %eax loads from the address label. I have a function with the signature : extern "C" int foo(int a, int b, int c, int d, int e); which is in fact How can a write a procedure in MASM that accepts one or more parameters and return one or more values ? I am trying the following code, DATA SEGMENT DATA ENDS ;; MOV AX,DATA MOV DS,AX PUSH AX CALL FAR PTR CONV_ROUT MOV AX,4C00H INT 21H CODE ENDS END START Welcome to The MASM Forum. What's wrong with that simple code, I don't know what's happened, the push eax instruction occurs that error: . xdata for a function's structured exception handling unwind behavior. Or since this is 64-bit mode, you'd movsd xmm0, [some_float] unless you really wanted 80-bit x87 FP for some reason. Can we confirm this? coder. News: Masm32 SDK description, downloads and other helpful links The StrToStack macro splits a string to DWORD values and pushes them to the stack : Code Select Expand. Started by ragdog, November 29, 2007, 09:22:17 AM. data format byte "Arg1: %d", 10, 0 . The program cleared arrays using stosd. pdata and unwind information in . Does it require a special compiler or how would you write an opcode program and compile it. January 12, 2025, 10:11:51 PM. somedword fails during asm time. – We are starting to learn about push and pop in my MASM class, and like many, we are using Kip Irvine's stuff. Копирование данных. push. December 12, 2024, 12:19:11 PM. DATA dwSize COORD <20, 20> . Инструкция mov. Howdy, your new console template here. code printData proc mov rbx, 100 push rbx lea rax, format; format address push rax call printf; throw unhandled exception ntdll. The MASM Forum General The Campus Pause Before Exit. exe users to specify how a frame function unwinds. txt file in 64-byte blocks, encrypt each block and then write it to another . I am currently trying to call a standard-library-function (e. If the optional CODE keyword is specified, the unwind code entry is given a modifier of 1. I'm currently learning masm and I am having a problem calling an external function. Add a masm; or ask your own question. Any help is appreciated. Go Down Pages 1 2 3. push 10 push 20. Have a look at the MASM64 project as it has the Should be standard use of a stack. I started off with the WndProc I have checked MASM and MSVC for the 32-bit case and 3 byte strutures. Viewed 5k times 6 . My First MASM 64-bit Hello World console. PUSHREG allows ml64. data . That's not really the case. them on stack. 1. Modified 8 years, 1 month ago. I thought on the offhand chance it wasn't pushing a full 32-bit value, that would force it. 57 push edi 00401342 ³. Замечания. " You can do basically the same by pushing the registers using eight push instructions, but that will push a different value for sp. The first one is preferred since TASM (A MASM compatible assembler) doesn't support the latter form. POPAD 1. News: push 2+4 ; mode 2 = ignore case of first letter, 4 = whole word push chr$("test") ; the pattern push chr$("This is a Test") ; The MASM Forum Archive 2004 to 2012; General Forums; The Campus; Lea, Offset, and Addr; Lea, Offset, and Addr. Ask Question Asked 14 years, 10 months ago. Установка и начало работы. . January 04, 2025, 02:25:29 PM. Started by Alek, December 03, 2018, 11:53:12 AM. CODE INVOKE SetConsoleScreenBufferSize, hConsoleOutput, DWORD PTR [dwSize] В этой статье. 00401340 Ú. News: MASM32 SDK Description, downloads and other helpful links MASM32. Стек в ассемблере Intel x86-64, инструкции push и pop, добавление в стек и извлечение из стека, Основы ассемблера MASM для Intel x86-64. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Using register EAX, you assign the upper word to AX. The one we will use in CS216 is the Microsoft Macro Assembler (MASM) assembler. PUSHREG позволяет ml64. PUSH/POP Style Parameters; PUSH/POP Style Parameters. You must use an external tool for encrypting your code/data. I was assigning each immediate value to edx before pushing it onto the stack. calling a dll in masm and C. August 05, 2009, 02:47:47 PM. push x copies x on the top of the stack, and moves the stack pointer so that the new top is below the pushed value (remember that on x86, the stack grows downwards in memory). cmp al, 10 ; Check to see if digit is 0-9. dlrhohlzcrqznunwllwzeoackdzxwjmpdmtyrceityhipoaagpvxr