Microsoft Windows 7 Professional 64-Bit Operating System Software - W/Service Pack 1, License & Media, 1PC, OEM, DVD, LCP, English - FQC-08289. Go. Asm Assembler Manual. The scope of a label defines from where it can be accessed using. Lets look at these two types of re- usable labels. Therefore the symbol sent to the debugger. CALCULATE. fin, and another way to jump past that unique label. JZ > CALCULATE. Similarly. if you have a procedure in another executable (usually a Dll) you can do. You could call it as follows: -. In your list of Dlls you give to Go. Zebra Label Vista 64 BitsLink you will specify My. Dll. Go. Link. will first look for the code label CALCULATE in the object files, but will then. Dlls. Most other linkers look in library files (. If the linker does not find the destination of the call. It is the programmer's job to ensure that these parameters are sent to the API. The parameters contain the information, or pointers to information, which tell the. API what to do. Sometimes the parameters contain addresses of places in memory where the API. Windows uses the standard calling convention (STDCALL) and. Windows uses the so- called fast calling convention (FASTCALL). Go. Asm creates the correct. If you are writing only. PUSH and CALL to send the parameters, but if you want to port your. Summary of all Single and Multifunction Printers currently available for purchase. Includes links to compare products, obtain more information about a specific model. Windows later, you will need to change these to ARG and INVOKE. In both 3. 2- bit. CALL to call procedures in your own executables, unless. The API uses the parameters on the stack and before returning it restores. However. subsequent parameters are put on the stack. The caller needs to ensure that the stack. RSP) is moved to the top of the parameters as usual, allowing for the. API to keep them on. Another difference is that the. API does not restore the stack into equilibrium before returning from the call (this change makes. APIs which do not have a fixed number of parameters). These. are also sometimes called . The Unicode version. API will end in . When you link your object. API in the other executable. Go. Link). this is probably because you have forgotten to add the required A or W. See. writing Unicode programs for information. This is because 6. Windows has ANSI and Unicode versions of the. APIs just like 3. Windows. Often in Windows you need to send to an API. MBTITLE DB 'Hello',0. MBMESSAGE DB 'Click OK',0. PUSH 4. 0h, ADDR MBTITLE, ADDR MBMESSAGE, . Then Go. Asm creates the correct instruction. No symbol is made. For example: -. PUSH < 2. PUSH < 2. 3,6 DUP 2. PUSH < 'Hi',0. Dh,0. Ah,'There',0> ; push a pointer to the null terminated string on two lines. You can also use the < and > operators in this way with ARG and after INVOKE. Then Go. Asm gives the pointer to the data so created to the instruction. No symbol is. made for debugging purposes. The difference is in the use of the ADDR operator. But what is missing from this instruction is whether. In other. words should one, two or four bytes of memory be altered? The syntax in other. MOV DWORD PTR . Therefore you must give this a type indicator too. INC B. Some of these examples use named memory references, others. AND B? Also some. ARPL, BOUND, BSF, BSR, CMOV (in all forms). CMPXCHG, and CMPXCHG8. B. You are not. allowed to use the multiply sign (asterisk) inside square brackets. Although Go. Asm recognises them if you use them in places where. Here are some examples: -. DB (2+3. 0h)/(2+1). DD (2. 00. 0h+4. 0h- 2. DD SIZEOF HELLO/2. DD 4. 44. 44. 4h & 2. DB 2. 0h/2 DUP 4. DD globule. MUL and DIV are used at compile- time and not. IMUL and IDIV. See. Go. Asm expects all real numbers in the source script to be. The point can be anywhere within. The real number may have a signed decimal exponent. Here are some examples of real number data declarations: -. DD 3 DUP 7. 6. 78. E- 2. DQ 6. 78. 2. E3. You may also declare PI directly either as a tword, qword or dword as. DD PI ; pi as a dword. DQ PI ; pi as a qword. DT PI ; pi as a tword. Go. Asm tries to achieve maximum accuracy in providing pi by writing a. The first places. In the case of a tword (8. In order to do this you will need. Go. Bug). Then you can declare this number. DIRECT. In this. case the number is positive because the sign bit is not set. The. remainder of the first four hex digits contain the exponent. This is. biased by a value of +3. FFEh in 8. 0 bit real numbers. This makes it difficult to work out the. In other words Go. Asm is given the value of the characters. Windows. When Go. Asm loads in the object file. Windows. This means that the value given. Go. Asm by Windows will match that in the current character. The correct characters are. Unicode value. If necessary you can arrange for your code to test. You can also test. The resource APIs provide a way this can be done automatically - . Go. RC, my resource compiler. They can range from very loose arrangements to highly. Structures are very important in Windows. Go. Asm supports all types. The following code sends the LVM. The column details are contained in the LV. Here is how it might be used in 3. PUSH ADDR LV. In one sense. This mask is important because a later version of the structure. So it might. be better to declare the structure in data like this so that the mask can be. LV. This is done in two stages. The. first stage is to make a template by using STRUCT and give a name to the template. If you prefer. you can also mark the end of the template by giving the structure name again. ENDS eg. You do this by using the template. Lv. 1 LV. These can then be. This is. because Go. Asm creates symbols for all the members of the structure and. As far as I am aware this is unique to. Go. Asm and other assemblers do not do this. As an example, the OFNHook. Proc callback procedure receives. Windows information in a WM. The l. Param parameter. OFNOTIFY structure. This is a nested. OFNOTIFY STRUCT. hdr NMHDR. NMHDR structure is: -. So within your window procedure you can get the value of the member. From in the NMHDR (identifier. MOV ESI. These. are their correct offsets from the beginning of the OFNOTIFY structure. This is done by including the structure templates in the. Instead. you only specify the ultimate name (. The override. is also carried out into nested structures, so if you use the same. This is because Go. Asm cannot know in advance how large. STRUC means the same as STRUCT. There is no need to. DD 0. DD 2 DUP 0. DD 0. RECT STRUCT DD 4 DUP 0 ENDS. However, where members are. This does not result in the. DD ? Since no label. RECT, no symbols at all will be created. Symbols will only be made. This is to avoid duplication of symbol. Initialisation of. The symbols created (and passed to the debugger) are: -. MOV D. The only difference is that. RECT structure is not available for use elsewhere. Each < bracket will go deeper into. When. coming out of a nest a comma is expected after the > bracket. So in. the Struct. Test nested structure (given above): -. Struct. Test < 2. RECT member. rc. 1 Struct. Test < ,< 1. Struct. Test < ,< 1. RECT member: -. rc. Struct. Test < ,,4. A good way to keep track of the brackets is to visualise a question mark. Or you can even insert the. Struct. Test < ?,?,4. Override priority. The higher the level of override the greater its priority so for. DD 1. top DD 2. right DD 3. DD 4. Struct. Test STRUCT. RECT < 3. 33. 3h,4. Hello Struct. Test < ,< ,0. Bh,0. Ch,> ,,>. Then RECT would be initialised to 3. Bh,0. Ch,4. Overrides naming members using . Like structures, no data area is actually created when you. This is done when you use the template. Unions are useful if you want to use. Which label you address at run- time. The size of a union is always set to the largest. You can mix unions with structures to form complex. You can declare unions in local data and repeat them in the same way. Why only 4 bytes? The end of the union template is marked by ENDS although you can use. ENDUNION if you prefer. The only difference is that. Laugh and Zebra are not available for use elsewhere. Only. the very last byte survived. The word is defined. If the. word as defined means a string, then traditionally it would be called a text. If the word as defined means something more than just a number or string. This is because traditionally the word would be defined using the. MACRO operator. Just use the one. You can use the continuation character (. This. avoids syntax problems. Once a word has been. Go. Asm will warn you of. The first uses =. EQU and the third uses #define. They all do the same thing. Here are some examples: -. SKIP. For example: -. NT. These values. So, for example: -. RECTB(%a,%b,%c,%d) = DD %a,%b,%c,%d. Then, you can declare four dwords initialised as specified in the arguments: -. RECTB (1. 0,1. 0,1. DD 1. 0,1. 0,1. 00,2. Here is another example using #define: -. DBDATA(%a,%b) DB %a DUP %b. DBDATA(3,'x') ; same as DB 3 DUP 'x'. There is an important syntax rule when using arguments in definitions. When giving the. definition the arguments in brackets must be tight against the word which. RECTB(%a,%b,%c,%d). RECTB (%a,%b,%c,%d). This rule is to ensure that Go. Asm knows the things in brackets are. This avoids other things being. Hence the percentage sign is used in the above examples. For example: -. #define WS. Go. Asm is quite happy with. In fact in Go. Asm the brackets are optional, so this is also perfectly. WS. The above. example can then be re- written as: -. WS. It has an argument which holds the number of. In the code section: -. Wnd. Proc: ; name of this procedure. OPEN. Then at EBP+4h we find the return address after. At EBP we have the previous value of EBP which we pushed. Then at EBP- 4h to EBP- 1. DC, h. Brush, h. Pen, DATA1, DATA2 and DATA3 (or whatever you want to. Then at EBP- 1. Ch we have the value of EBX when it was. Likewise EDI is at EBP- 2. ESI is at EBP- 2. All these values are protected while the. To access the data. You don't have. to access the data by name. In this example MOV EAX. This is a matter of style and taste. In this example, the first dword of local data. EBP- 4h. Subtract 4 from this value to access each. But if the line defining. REPORT is commented out, then it is not displayed. For example. suppose you have macro. ARGCOUNT=6 \. PUSH %f \. ARGCOUNT > =5 \.
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