;Testname=unoptimized; Arguments=-O0 -felf -oelfso.o; Files=.stdout .stderr elfso.o ;Testname=optimized; Arguments=-Ox -felf -oelfso.o; Files=.stdout .stderr elfso.o ; test source file for assembling to ELF shared library ; build with: ; nasm -f elf elfso.asm ; ld -shared -o elfso.so elfso.o ; test with: ; gcc -o elfso elftest.c ./elfso.so ; ./elfso ; (assuming your gcc is ELF, and you're running bash) ; This file should test the following: ; [1] Define and export a global text-section symbol ; [2] Define and export a global data-section symbol ; [3] Define and export a global BSS-section symbol ; [4] Define a non-global text-section symbol ; [5] Define a non-global data-section symbol ; [6] Define a non-global BSS-section symbol ; [7] Define a COMMON symbol ; [8] Define a NASM local label ; [9] Reference a NASM local label ; [10] Import an external symbol ; [11] Make a PC-relative call to an external symbol ; [12] Reference a text-section symbol in the text section ; [13] Reference a data-section symbol in the text section ; [14] Reference a BSS-section symbol in the text section ; [15] Reference a text-section symbol in the data section ; [16] Reference a data-section symbol in the data section ; [17] Reference a BSS-section symbol in the data section BITS 32 GLOBAL lrotate:function ; [1] GLOBAL greet:function ; [1] GLOBAL asmstr:data asmstr.end-asmstr ; [2] GLOBAL textptr:data 4 ; [2] GLOBAL selfptr:data 4 ; [2] GLOBAL integer:data 4 ; [3] EXTERN printf ; [10] COMMON commvar 4:4 ; [7] EXTERN _GLOBAL_OFFSET_TABLE_ SECTION .text ; prototype: long lrotate(long x, int num); lrotate: ; [1] push ebp mov ebp,esp mov eax,[ebp+8] mov ecx,[ebp+12] .label rol eax,1 ; [4] [8] loop .label ; [9] [12] mov esp,ebp pop ebp ret ; prototype: void greet(void); greet push ebx ; we'll use EBX for GOT, so save it call .getgot .getgot: pop ebx add ebx,_GLOBAL_OFFSET_TABLE_ + $$ - .getgot wrt ..gotpc mov eax,[ebx+integer wrt ..got] ; [14] mov eax,[eax] inc eax mov [ebx+localint wrt ..gotoff],eax ; [14] mov eax,[ebx+commvar wrt ..got] push dword [eax] mov eax,[ebx+localptr wrt ..gotoff] ; [13] push dword [eax] mov eax,[ebx+integer wrt ..got] ; [1] [14] push dword [eax] lea eax,[ebx+printfstr wrt ..gotoff] push eax ; [13] call printf wrt ..plt ; [11] add esp,16 pop ebx ret SECTION .data ; a string asmstr db 'hello, world', 0 ; [2] .end ; a string for Printf printfstr db "integer==%d, localint==%d, commvar=%d" db 10, 0 ; some pointers localptr dd localint ; [5] [17] textptr dd greet wrt ..sym ; [15] selfptr dd selfptr wrt ..sym ; [16] SECTION .bss ; an integer integer resd 1 ; [3] ; a local integer localint resd 1 ; [6]