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| -rw-r--r-- | Makefile | 7 | ||||
| -rw-r--r-- | bismuth.asm | 175 |
2 files changed, 182 insertions, 0 deletions
diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..d2167c6 --- /dev/null +++ b/Makefile @@ -0,0 +1,7 @@ +bismuth: bismuth.asm + nasm -g -f elf32 bismuth.asm + ld -m elf_i386 bismuth.o -o bismuth + +.PHONY: clean +clean: + rm -f bismuth.o bismuth diff --git a/bismuth.asm b/bismuth.asm new file mode 100644 index 0000000..b5f6182 --- /dev/null +++ b/bismuth.asm @@ -0,0 +1,175 @@ +section .data +; This is stack of 4KB: + db 4096 dup 0 +stackbottom: +; Place to copy msg content into: +msg: + db 1024 dup 0 +; And finally our program: +program: + dd bismuth ; We want to use our main interpreter, bismuth. + dd data + dd prog + dd data + dd 0x0a20202e + dd 0x2e2e6948 + dd quote, eval, 0, pop + dd quote, eval, 0 + dd 0, quote, msg, copywords + dd data, msg, eval, msg, eval, 0, output + dd 0 + + +; The input is in esi, pop dword from it: +%macro bisnext 1 + mov %1, dword [esi] + add esi, 4 +%endmacro + +; Top of the stack is in edi, pop dword from it: +%macro bispop 1 + mov %1, dword [edi] + add edi, 4 +%endmacro + +; Top of the stack is in edi, pop byte from it: +%macro bispopbyte 1 + mov %1, byte [edi] + inc edi +%endmacro + +; Top of the stack is in edi, push dword onto it: +%macro bispush 1 + sub edi, 4 + mov dword [edi], %1 +%endmacro + +; Top of the stack is in edi, push byte onto it: +%macro bispushbyte 1 + dec edi + mov byte [edi], %1 +%endmacro + +; Calling conventions for interpreters: +%macro bisinterpret 1 + push esi + mov esi, %1 + bisnext eax + add eax, 4 + push ebp + mov ebp, esp + call eax + mov esp, ebp + pop ebp + pop esi +%endmacro + + +section .text +global _start +_start: + mov esi, program ; We will read and execute program + mov edi, stackbottom ; and write results onto stack. + bisnext eax ; Read interpreter + bisinterpret eax ; and start interpretation. + ; After execution of program we will exit properly: + mov ebx, 0 ; We have no error (error code = 0) + mov eax, 1 ; and we want to exit. + int 0x80 ; Send this to kernel. + ; That's all! =) + +bismuth: + dd bismuth + mov esi, [ebp+4] +bismuthloop: + bisnext eax + cmp eax, 0 + je bismuthend + bisinterpret eax + jmp bismuthloop +bismuthend: + mov [ebp+4], esi + ret + +prog: + dd prog +progloop: + bisnext eax + cmp eax, 0 + je progend + bisinterpret eax + jmp progloop +progend: + ret + +pop: + dd pop + add edi, 4 + ret + +copy: + dd copy + mov eax, dword [edi] + sub edi, 4 + mov dword [edi], eax + ret + +quote: + dd quote + mov esi, [ebp+4] + bisnext eax + bispush eax + mov [ebp+4], esi + ret + +eval: + dd eval + mov esi, [ebp+4] + bispop eax + bisinterpret eax + mov [ebp+4], esi + ret + +data: + dd data + mov esi, [ebp+4] + push edi +dataloop: + bisnext eax + cmp eax, eval + je dataeval + cmp eax, 0 + je dataend + bispush eax + jmp dataloop +dataeval: + bisinterpret eax + jmp dataloop +dataend: + pop eax + sub eax, edi + bispush eax + mov [ebp+4], esi + ret + +copywords: + dd copywords + bispop ebx + bispop ecx + sub ebx, 4 +copywordsloop: + bispop eax + mov dword [ebx+ecx], eax + sub ecx, 4 + jnz copywordsloop + ret + +output: + dd output + bispop edx + mov ecx, edi + mov ebx, 1 + mov eax, 4 + int 0x80 + add edi, edx + ret |