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chastitywhiterose 01 Jan 2026, 05:30
Here it is. My most recent project since I perfected chastehex. This small program allows moving the cursor anywhere in the terminal. It took me awhile to figure out how to use the escape codes to position the cursor. As it turns out, I simply had to write my own implementation of strcpy along with my own intstr function to build the escape sequence string with the right information.
It is just a start, but since this works in a Linux terminal, it means I could theoretically start designing simple games in Linux x86 assembly language. I wrote some other games in C before but doing it in assembly would be a first time. I will probably make small games within my skill level based on this foundation. Code: format ELF executable entry main include 'chastelib32.asm' include 'ansi.asm' main: ; the main function of our assembly function, just as if I were writing C. keyloop: mov [radix],16 ; Choose radix for integer output! mov [int_width],8 mov [int_newline],0 ;disable automatic printing of newlines after putint ;first clear the screen mov eax, ansi_clear call putstring ;reset cursor to home AKA top left of screen mov eax,ansi_home call putstring mov eax,prefix_k call putstring mov eax,[key] call putint call putline mov eax,prefix_x call putstring mov eax,[x] call putint call putspace mov eax,prefix_y call putstring mov eax,[y] call putint call putline mov eax,msg call putstring cmp [showhelp],0 jz help_skip print_help: mov eax,help call putstring call putline help_skip: ;move the cursor with the function I wrote in ansi.asm call move_cursor call read_key cmp [key],0x68 jz toggle_help cmp [key],0x41 jz key_up cmp [key],0x42 jz key_down cmp [key],0x44 jz key_left cmp [key],0x43 jz key_right jmp keyloop_end ;conditional blocks based on input key_up: dec [y] jmp keyloop_end key_down: inc [y] jmp keyloop_end key_left: dec [x] jmp keyloop_end key_right: inc [x] jmp keyloop_end toggle_help: xor [showhelp],1 jmp keyloop_end keyloop_end: cmp [key],'q' ;loop will go until q is pressed jnz keyloop main_end: mov eax, 1 ; invoke SYS_EXIT (kernel opcode 1) mov ebx, 0 ; return 0 status on exit - 'No Errors' int 80h ; string variables to display useful information msg db "Press q to quit, h for help", 0Ah,0 ; assign msg variable with your message string help db "This program operates the terminal by using ANSI escape sequences. " db "The arrow keys move the cursor around the terminal. " db "That is all there is for now, but it is possible that with more code, this could make a small game." db "But don't forget, this program only works if the Linux command `stty cbreak` is run first." db 0xA,"This turns off line buffering so that each key operates immediately." db 0xA,"You can turn this help message on or off with the h key again.",0 showhelp dd 0
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01 Jan 2026, 05:30 |
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Jessé 03 Jan 2026, 23:29
Seeing 'ANSI' and 'Linux' in the same paragraph is weird, but, anyways...
Have you ever heard of libncurses? I think is the best way to what you are looking for. It has even mouse support, and many applications use it, like, htop, top, nvtop, nano, etc.. Provides a blank terminal canvas, with even (abstraction of) windows! Try it, I think you'll never regret. To me it take half a day to learn about, and another one to do something useful with it (a digital clock, with sizeable digits). I don't know if still has 32-bit support, perhaps you'll need to go 64-bit to use it. |
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03 Jan 2026, 23:29 |
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Jessé 04 Jan 2026, 19:49
Hmm, I understood.
To use libraries, you will have to use 'extrn' directive to import functions, I guess, for fasm (1), and use external linker (like 'ld') to link the '.o' object files where you append the library names. I'm on fasm2, so, I cannot not guarantee that it is the same, but, probably it is. |
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04 Jan 2026, 19:49 |
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ProMiNick 04 Jan 2026, 21:35
To use libraries in linux is similar to windows - func names must be listed in stringtable of elf. Table of pointers to that functions is placed after last (counted initialized & reserved ones) byte by default. That is simplest way to make elf executable with dinamicaly loaded *.so. Everything without garbage as external linker.
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04 Jan 2026, 21:35 |
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Jessé 05 Jan 2026, 10:52
Take this example on how to use external libraries:
Code: format ELF64 extrn printf extrn __libc_start_main extrn stdout public Start section '.text' executable align 4 Start: endbr64 push rsp mov r9, rdx xor r8d, r8d xor ecx, ecx lea rdx, [rsp+16] mov esi, [rsp+8] lea rdi, [main] jmp plt __libc_start_main align 4 main: endbr64 enter 0, 0 lea rdi, [msg0] xor al, al call plt printf leave xor eax, eax ret section '.data' writeable msg0: db 'This is a fasm 1 program, compiled in' db ' a traditional way!',10,0 To compile: Quote:
-lc -> to link with libc; -lpthread -> to link with libpthread; -lncurses -> to link with lincurses And so on... Optionally, you can optimize the final executable size with: Quote:
I've tested this with fasm 1 and it worked. |
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05 Jan 2026, 10:52 |
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Jessé 05 Jan 2026, 11:01
The only drawback I had with fasm 1 (instead of fasm2) is that I couldn't find a way to access using GOT. But I had not searched deeper.
Example: 'mov rdi, [got stdout]' Simply does not work with fasm 1, but: 'mov rdi, [got.stdout]' Works fine with fasm2. |
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05 Jan 2026, 11:01 |
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chastitywhiterose 06 Jan 2026, 01:53
I have no idea how any of that works but maybe I can play around with it and see if it lets me do some combinations of C and Assembly. Perhaps it could be used to write more portable code between operating systems.
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06 Jan 2026, 01:53 |
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