forked from Kingcom/armips
-
Notifications
You must be signed in to change notification settings - Fork 0
License
hexkyz/armips
Folders and files
Name | Name | Last commit message | Last commit date | |
---|---|---|---|---|
Repository files navigation
ARMIPS assembler v0.8, released whenever by Kingcom https://github.com/Kingcom/armips http://aerie.wingdreams.net/ ################################# # 0. TABLE OF CONTENTS # ################################# 1. Introduction 1.1 Motivation 1.2 Usage 1.3 Change log 2. General Information 3. Features 3.1 Files 3.2 Comments 3.3 Labels 3.4 equ 3.5 Math Parser 3.6 Load delay detection 3.7 Strings 3.8 Areas 3.9 Symbol files 3.10 C/C++ importer 4. Assembler Directives 4.1 General Directives 4.2 MIPS Directives 4.3 ARM Directives 5. Macros 5.1 Assembler-defined MIPS macros 5.2 Assembler-defined ARM macros 5.3 User defined macros 6. Known issues ################################# # 1. INTRODUCTION # ################################# 1.1 Motivation I started writing this assembler when I got into PSX hacking, as the only available assemblers were less than user friendly. This assembler is an attempt to fix of all of the problems with currently available assemblers and to allow working with several different code binaries in the same game. It won't erase any code, it will just overwrite what the user wants to overwrite. The second version added ARM/THUMB support. It can be used for both GBA and NDS and includes both instruction sets. ARM has been implemented according to GBATEK by Martin Korth, and most pseudo opcodes and aliases are included (for example, mov for mcr/mrc and mrs/msr). This is likely the final release, except for potential bug fixes of critical problems. 1.2 Usage The assembler is called from the command line, and the arguments are as follows: armips.exe code.asm [-temp tempfile.txt] [-sym symfile.sym] [-erroronwarning] Code.asm is the main file of your assembly code. It can open and include other files, and basically do everything you want. The optional -temp parameter specifies a text file where all the temporary assembly data will be written to for debugging purposes. It will look like this: ; 1 file included ; test.asm 00000000 .open "SLPM_870.50",0x8000F800 ; test.asm line 1 8000F800 .org 0x800362DC ; test.asm line 5 800362DC jal 0x801EBA3C ; test.asm line 7 800362E0 .Close ; test.asm line 9 The second optional parameter, -sym, allows you to specify a file to output all the labels to. This can be used with no$gba for easier debugging. The last optional parameter, -erroronwarning, has the same effect as the .erroronwarning directive. See 4.1 for more details. 1.3 Change log 0.8 -huge rewrite with many enhancements and fixes -can now read from UTF8, UTF16, and Shift-JIS files and convert the input correctly -PSP support, load ELFs with .loadelf -able to import and relocate static C/C++ libraries -new -sym2 format for use with PPSSPP -new directives: .sym, .stringn, .sjis, .sjisn, .function, .endfunction, .importlib, .loadelf 0.7d -added automatic optimizations for several ARM opcodes -many bugfixes and internal changes -added static labels -new directives: .warning, .error, .notice, .relativeinclude, .erroronwarning, .ifarm, .ifthumb -quotation marks can now be escaped in strings using \". 0.7c -Macros can now contain unique local labels -area directive added -countless bugfixes -no$gba debug message support -full no$gba sym support 0.7b -ARM/THUMB support -fixed break/syscall MIPS opcodes -added check if a MIPS instruction is valid inside a delay slot -fixed and extended base detection -added "." dummy label to the math parser to get the current memory address -added dcb/dcw/dcd directives 0.5b -Initial release ################################# # 2. GENERAL INFORMATION # ################################# The assembler includes the whole MIPS R3000 instruction set, as well as the complete ARM7/ARM9 instruction set used by GBA and NDS, both THUMB and ARM mode. There are also several other features. Among these features are: -a full fledged C-like math parser. It should behave exactly like in any C/C++ code, including all the weirdness. All immediate values can be specified by an expression, though some directives can't use variable addresses including labels -you can open several files in a row, but only one output file can be open at any time. You can specify its address in memory to allow overlay support. Any file can cross-reference any other included file -local, static, and global labels (see 3.3) -table support for user defined text encodings (see 3.7) -several MIPS macros to make writing code easier and faster (see 4.1) -user defined macros (see 5.3) -built-in checks for possible load delay problems (see 3.6) -optional automatic fix for said problems by inserting a nop between the instructions -output of the assembled code to a textfile, with RAM addresses and origin (see 1.2) -a directive to ensure that data is not bigger than a user defined size (see 3.8) ################################# # 3. FEATURES # ################################# 3.1 Files Unlike other assemblers, you don't specify the input/output file as a command line argument. You have to open the file in the source code, and also close it yourself. This was done in order to support overlays, which are very common in PSX and NDS games. Instead of only having one output file, you can have as many as you need - each with its own address in memory. The files can cross-reference each other without any problems, so you can call code from other, currently not opened files as well. .Open "SLPS_035.71", 0x8000F800 ; ... .Close .Open "System\0007.dat", 0x800CC000 ; ... .Close 3.2 Comments Both ; and // are supported for comments. 3.3 Labels There is support for both local, global and static labels. Local labels are only valid in the area between the previous and the next global label. Specific directives, like .org, will also terminate the area. A label is defined by writing a colon after its name. All labels can be used before they are defined. GlobalLabel: ; This is a global label @@LocalLabel: ; This is a local label, it is only ; valid until the next global one OtherGlobalLabel: ; this will terminate the area where ; @@LocalLabel can be used b @@LocalLabel ; as a result, this will cause an error Static labels behave like global labels, but are only valid in the very file they were defined. Any included files or files that include it cannot reference it. They can, however, contain another static label with the same name. @staticlabel: A label name can contain all characters from A-Z, numbers, and underscores. However, it cannot start with a digit. All label names are case insensitive. Additionally, "." can be used to reference the current memory address. 3.4 equ This works as a text replacement and is defined as follows: @@StringPointer equ 0x20(r29) There has to be a space before and after equ. The assembler will replace any occurance of @@StringPointer with "0x20(r29)". As it is a local equ, it will only do so in the current section, which is terminated by any global label or specific directives. This code: @@StringPointer equ 0x20(r29) lw a0,@@StringPointer nop sw a1,@@StringPointer will assemble to this: lw a0,0x20(r29) nop sw a1,0x20(r29) There can be both global and local equs, but unlike normal labels, they have to be defined before they are used. 3.5 Math Parser A standard math parser with operator precedence and bracket support has been implemented. It is intended to behave exactly like any C/C++ parser and supports all unary, binary and tertiary operators of the C language. Every numeral argument can be given as an expression, including label names. However, some directives do not support variable addresses, so labels can not be used in expressions for them. The following bases are supported: $A, 0xA and 0Ah for hexadecimal numbers 0o12 and 12o for octal numbers 1010b for binary numbers Everything else is interpreted as a decimal numbers, so a leading zero does not indicate an octal number. Be aware that every number has to actually start with a digit, unless you use $ for hexadecimal numbers. For example, as FFh is a perfectly valid label name, you have to write 0FFh in this case. Labels, on the other hand, cannot start with a digit. A few examples: mov r0,10+0xA+$A+0Ah+0o12+12o+1010b ldr r1,=ThumbFunction+1 li v0,Structure+(3*StructureSize) 3.6 Load delay detection This feature is still unfinished and experimental. It works in most cases, though. On MIPS platforms, any load is asynchronously delayed by one cycle. This means that the CPU won't stall if you attempt to use it before - and instead returns the old value on real hardware (emulators do not emulate this, which makes spotting these mistakes even more difficult). Therefore, the assembler will attempt to detect when such a case happens. The following code would result in a warning: lw a0,0x10(r29) lbu a1,(a0) This code doesn't take the load delay into account and will therefore only work on emulators. The assembler detects it and warns the user. In order to work correctly, the code should look like this: lw a0,0x10(r29) nop lbu a1,(a0) Here, one cycle is wasted with the nop and there will be no problems. However, the detection doesn't work in all cases. It can't check if the instruction at a branch destination uses a register that was loaded in the branch's delay slot, and it will give it a false alarm in the following example: bnez a0,@@branch1 nop j @@branch2 lw a0,(a1) @@branch1: lbu a2,(a0) You can fix the false warning by using the .resetdelay directive before the last instruction. bnez a0,@@branch1 nop j @@branch2 lw a0,(a1) .resetdelay @@branch1: lbu a2,(a0) This behavior may be fixed in a future revision. 3.7 Strings You can write ASCII text by simple using the .db/.ascii directive. However, you can also write text with custom encodings. In order to do that, you first have to load a table, and then use the .string directive to write the text. It behaves exactly like the .db instruction (so you can also specify immediate values as arguments), with the exception that it uses the table to encode the text, and appends a termination sequence after the last argument. This has to be specified inside the table, otherwise 0 is used. .loadtable "custom.tbl" .string "Custom text",0xA,"and more." The first and third argument are encoded according to the table, while the second one is written as-is. Quotation marks can be escaped by prefixing them with a backslash. Any backlash not followed by a quotation mark is kept as-is. If you want to use a backslash at the end of a string, prefix it by another backlash. For example, to write a quotation mark followed by a backlash: .ascii "\"\\" 3.8 Areas If you overwrite existing data, it is critical that you don't overwrite too much. The area directive will take care of checking if all the data is within a given space. In order to do that, you just have to give it the maximum size allowed. .area 10h .word 1,2,3,4,5 .endarea This would cause an error on assembling, because the word directive takes up 20 bytes instead of the 16 that the area is allowed to have. This, on the other hand, would assemble without problems: .org 8000000h .area 8000020h-. .word 1,2,3,4,5 .endarea Here, the area is 32 bytes, which is sufficient for the 20 bytes used by .word. Optionally, a second parameter can be given. The free size of the area will then be filled with bytes of that value. 3.9 Symbol files Functions. 3.10 C/C++ importer Linker. ################################# # 4. ASSEMBLER DIRECTIVES # ################################# These commands tell the assembler to do various things like opening the output file or opening another source file. 4.1 General Directives .psx Sets the architecture to PSX. .psp Sets the architecture to PSP. .gba Sets the architecture to GBA. It will default to THUMB mode, but it can switch to ARM at any time. ARM9 specific opcodes are disabled, so it is also usable for NDS ARM7 code. .nds Sets the architecture to NDS. It will default to ARM mode, but it can switch to THUMB at any time. .open FileName,RamAddress .open OldFileName,NewFileName,RamAddress Opens the specified file for output. If two file names are specified, then the assembler will copy the first file to the second path. If relative include is off, all paths are relative to the current working directory, so from where the assembler was called. Otherwise the path is relative to the including assembly file. RamAddress specifies the difference between the first byte of the file and its position in RAM. So if file position 0x800 is at position 0x80010000 in RAM, the header size is 0x80010000-0x800=0x8000F800. Only the changes specified by the assembly code will be inserted, the rest of the file remains untouched. .create FileName,RamAddress .createfile FileName,RamAddress Creates the specified file for output. If the file already exists, it will be erased. If relative include is off, all paths are relative to the current working directory, so from where the assembler was called. Otherwise the path is relative to the including assembly file. RamAddress specifies the difference between the first byte of the file and its position in RAM. So if file position 0x800 is at position 0x80010000 in RAM, the header size is 0x80010000-0x800=0x8000F800. .close .closefile Closes the currently opened output file. .headersize RamAddress Sets the header size to the given size. It will be used to calculate all addresses from that point on, until the next .headersize or .open/.create directive. The current address will also be set to RamAddress. .org RamAddress Sets the output pointer to the specified address. The file address is computed by subtracting the header size from the given address. .orga FileAddress Sets the output pointer to the specified address. The absolute file address is given. .include FileName[,encoding] Opens the file called FileName to assemble it. If relative include is off, all paths are relative to the current working directory, so from where the assembler was called. Otherwise the path is relative to the including assembly file. You can include other files up to a depth level of 64. This limit was added to prevent the assembler from crashing due to two files including each other over and over again. The encoding of the included file will be automatically detected if possible. However, this only works for files encoded as UTF8 or UTF16 that have a byte order mark. If the file is in another encoding, it must be manually specified as the second parameter. This is the list of supported values SJIS,Shift-JIS UTF8,UTF-8 UTF16,UTF-16,UTF16-BE,UTF-16-BE ASCII .incbin FileName[,start[,size]] .import FileName[,start[,size]] Inserts the file specified by FileName into the currently opened output file. If relative include is off, all paths are relative to the current working directory, so from where the assembler was called. Otherwise the path is relative to the including assembly file. Optionally, start can specify the start address from where the file should be imported, and size can specify the number of bytes to read. With this parts of files can be imported. .align [num] Writes zeroes into the output file until the output position is divisible by num. If num is not given, 4 will be used by default. num has to be a power of two. .radix base Sets the default base of numbers if no other prefix or suffix is given. Valid values are 2, 8, 10, and 16. The default base is 10. .fill length[,value] defs length[,value] Inserts length amount of bytes of value. If value isn't specified, inserts zeros. Only the lowest 8 bits of value are inserted. .byte value[,...] .db value[,...] .ascii value[,...] dcb value[,...] Inserts any number of bytes specified by the arguments. Value can be any equation, but only the lowest 8 bits are inserted. Value can also be a string in quotation marks. .halfword value[,...] .dh value[,...] dcw value[,...] Inserts any number of halfwords specified by the arguments. Value can be any equation, but only the lowest 16 bits are inserted. Value can also be a string in quotation marks, in that case, every letter is inserted as a halfword. .word value[,...] .dw value[,...] dcd value[,...] Inserts any number of words specified by the arguments. Value can be any equation. Value can also be a string in quotation marks, in that case, every letter is inserted as a word. .if equation Assembles the next block only if equation is nonzero. Can be inverted by .else or .elseif and has to be terminated by .endif. The code is still verified even if the condition is not met. .else Inverts previous .if or .elseif statement. .elseif equation Equation will only be checked if previous .if or .elseif statement was not met. Assembles the next block only if equation is nonzero. Can be inverted by .else or .elseif and has to be terminated by .endif. The code is still verified even if the condition is not met. .ifdef label Assembles the next block only if label is defined. Can be inverted by .else or .elseif and has to be terminated by .endif. The code is still verified even if the condition is not met. .ifndef label Assembles the next block only if label is not defined. Can be inverted by .else or .elseif and has to be terminated by .endif. The code is still verified even if the condition is not met. .ifarm Assembles the next block only if the active architecture is set to ARM at the time this directive is evaluated. Can be inverted by .else or .elseif and has to be terminated by .endif. The code is still verified even if the condition is not met. .ifthumb Assembles the next block only if the active architecture is set to THUMB at the time this directive is evaluated. Can be inverted by .else or .elseif and has to be terminated by .endif. The code is still verified even if the condition is not met. .loadtable TableName .table TableName Loads TableName for using it with the .string directive. The encoding has to be same as the assembly file's, as a simple binary comparison is used. All paths are relative to the current working directory, so from where the assembler was called. You can specify one or several termination bytes like this: 02=a /FF FF will be inserted at the end of the string. If it is not given, zero is used instead. .string "String" .str "String" Inserts the given string using the previously opened table. The previously specified termination sequence is appended at the end. .stringn "String" .strn "String" Inserts the given string using the previously opened table. This directive does not append the termination sequence at the end. .sjis "String" Inserts the given string using the Shift-JIS encoding. A null byte is appended after the string. .sjisn "String" Inserts the given string using the Shift-JIS encoding. This directive does not append the null byte at the end. .definelabel Label,value Defines Label with the given value. This may seem similar to equ, but you don't have to use this before using the label. It will also be added to the sym output. .area SizeEquation[,value] Opens a new area with the maximum size of SizeEquation. If the data inside the area is bigger than the maximum, the assembler will output an error and refuse to assemble the code. It has to be closed by a .endarea directive. If value is given, the free space of the area will be filled with bytes of that value. .endarea Closes a previously opened area. If the difference between the current ram address and that of the previous .area directive is bigger than the given size, an error will prevent successful assembling. .warning "Message" Prints the given message as a warning and sets the appropiate flags. Mostly only useful if used with conditionals. .error "Message" Prints the given message as an error and sets the appropiate flags. Mostly only useful if used with conditionals. .notice "Message" Prints the given message. Mostly only useful if used with conditionals .relativeinclude on/off If set to on, all file paths are relative to the file that uses them. It defaults to off. .erroronwarning on/off If set to on, a warning will be treated as an error and prevent successful assembling. It defaults to off. .importlib name[,ctorname] .importobj name[,ctorname] Imports the static C/C++ libary or object file name and relocates it to the current position. If relative include is off, all paths are relative to the current working directory, so from where the assembler was called. Otherwise the path is relative to the including assembly file. If ctorname is given, a global constructor stub with that name will be created. For more details about importing libraries, see section 3.10. .sym on/off Enables/disables sym output. .function funcname .func funcname Starts a new function with the name funcname. Funcname is also registered as a label. Starting a function without closing the previous one will implicitly close it. See section 3.9 for more about functions. .endfunction .endfunc Closes the currently open function. See section 3.9 for more about functions. 4.2 MIPS Directives .resetdelay Resets the current load delay status. This can be useful if the instruction after a delay slot access the delayed register, as the assembler can't detect that yet. .fixloaddelay Automatically fixes any load delay problems by inserting a nop between the instructions. Best used in combination with .resetdelay. .loadelf name[,outputname] Opens the specified ELF file for output. If two file names are specified, then the assembler will copy the first file to the second path. If relative include is off, all paths are relative to the current working directory, so from where the assembler was called. Otherwise the path is relative to the including assembly file. All segments are accessible by their virtual addresses, and all unmapped sections can be accessed by their physical position (through .orga). Currently this is only supported for the PSP architecture, and only for non-relocateable files. The internal structure of the file may be changed during the process, but this should not affect its behavior. 4.3 ARM Directives .arm This tells the assembler to use the full 32 bit ARM instruction set. It can be switched to THUMB at any time. NDS will default to this instruction set. .thumb This tells the assembler to use the cut-down 16bit THUMB instruction set. It can be switched to ARM at any time. GBA will default to this instruction set. .pool This directive works together with a pseudo opcode. In the code, you can use an ldr instruction to load a full 32 bit immediate. This immediate will be saved inside one of these pools. Example: ldr r0,=0xFFEEDDCC ; ... .pool Here, the ldr instruction will be assembled as a PC-relative load and the value will be written into the pool. The range is limited, so you may have to define several pools. .pool will automatically align the position to a multiple of 4. .msg Inserts a no$gba debug message as described by GBATEK. ################################# # 5. MACROS # ################################# 5.1 Assembler-defined MIPS macros There are various macros built into the assembler for ease of use. They are intended to make using some of the assembly simpler and faster. At the moment, these are all the MIPS macros included: li reg,Immediate la reg,Immediate Loads Immediate into the specified register by using a combination of lui/ori, a simple addiu or a simple ori. lb reg,Address lbu reg,Address lh reg,Address lhu reg,Address lw reg,Address Loads a byte/halfword/word from the given address into the specified register by using a combination of lui and lb/lbu/lh/lhu/lw. ulh destreg,imm(sourcereg) ulh destreg,(sourcereg) ulhu destreg,imm(sourcereg) ulhu destreg,(sourcereg) Loads an unaligned halfword from the address in sourcereg. It uses a combination of several lb/lbus and oris. ulw destreg,imm(sourcereg) ulw destreg,(sourcereg) Loads an unaligned word from the address in sourcereg. It uses a combination of lwl/lwr. sb reg,Address sh reg,Address sw reg,Address Writes a byte/halfword/word to the given address by using a combination of lui and sb/sh/sw. ush destreg,imm(sourcereg) ush destreg,(sourcereg) Loads an unaligned halfword to the address in sourcereg. It uses a combination of several sb/sbus and shifts. usw destreg,imm(sourcereg) usw destreg,(sourcereg) Loads an unaligned word to the address in sourcereg. It uses a combination of swl/swr. blt reg1,reg2,Dest bge reg1,reg2,Dest If reg1 is lower than/greate or equal than reg2, branches to the given address. A combination of sltu and beq/bne is used. blt reg,Imm,Dest bge reg,Imm,Dest If reg is lower than/greater or equal than Imm, branches to the given address. A combination of li, sltu and beq/bne is used. bne reg,Imm,Dest beq reg,Imm,Dest If reg is not the same/the same as Imm, branches to the given address. A combination of li and beq/bne is used. rol reg1,reg2,reg3 ror reg1,reg2,reg3 Rotates reg2 left/right by the value of the lower 5 bits of reg3 and stores the result in reg1. A combination of sll, srl and or is used. rol reg1,reg2,Imm ror reg1,reg2,Imm Rotates reg2 left/right by Imm and stores the result in reg1. A combination of sll, srl and or is used. Additionally, there are upper and lower versions for many two opcode macros. They have the same names and parameters as the normal versions, but .u or .t is appended at the end of the name. For example, li.u will output the upper half of the li macro, and li.l will output the lower half. The following macros support this: li,la lb,lbu,lhu,lw sb,sh,sw This can be used when the two halves of the macros need to be used in nonconsesutive positions, for example: li.u a0,address jal function li.l a0,address 5.2 Assembler-defined ARM macros The assembler will automatically convert the arguments between the following opcodes if possible: mov <-> mvn bic <-> and cmp <-> cmn E.g., "mov r0,-1" will be assembled as "mvn r0,0". Additionally, "ldr rx,=immediate" can be used to load a 32-bit immediate. The assembler will try to convert it into a mov/mvn instruction if possible. otherwise, it will be stored in the nearest pool (see the .pool directive). "add rx,=immediate" can be used as a PC-relative add and will be assembled as "add rx,r15,(immediate-.-8)". 5.3 User defined macros The assembler allows the user to create his own macros. This is an example macro, a recreation of the builtin macro for li: .macro myli,dest,value .if value < 0x10000 ori dest,r0,value .elseif (value & 0xFFFF8000) == 0xFFFF8000 addiu dest,r0,value & 0xFFFF .elseif (value & 0xFFFF) == 0 lui dest,value >> 16 .else lui dest,value >> 16 + (value & 0x8000 != 0) addiu dest,dest,value & 0xFFFF .endif .endmacro The macro has to be initiated by a .macro directive. The first argument is the macro name, followed by a variable amount of arguments. The code inside the macro can be anything, and it can even call other macros (up to a nesting level of 128 calls). The macro is terminated by a .endmacro directive. It is not assembled when it is defined, but other code can call it from now on. All arguments are simple text replacements, so they can be anything from a number to a whole instruction parameter list. The macro is then called like this: myli a0,0xFFEEDDCC This code will, in this case, assemble to the following: lui a0,0xFFEF addiu a0,a0,0xDDCC The user can define a theoretically infinite amount of macros. Like all the other code, any equs are inserted before they are resolved. With the latest revision, macros can also contain local labels that are changed to an unique name. Global labels, however, are uneffected by this. The label name is prefixed by the macro name and a counter id. This label: .macro test @@MainLoop: .endmacro will therefore be changed to: @@test_00000000_mainloop Each call of the macro will increase the counter. ################################# # 6. KNOWN ISSUES # ################################# -the load delay check can't detect if an opcode is inside a delay slot, and if it will be used by the first instruction of the branch destination
About
No description, website, or topics provided.
Resources
License
Stars
Watchers
Forks
Packages 0
No packages published
Languages
- C++ 95.4%
- C 2.2%
- Assembly 2.0%
- CMake 0.4%