nasm - Addressing an array of pointers in asm -

i have routine can call this:

mov rdi, struc_point mov rsi, struc_color call put_pixel 

now, create array of pointers have color table. have this, , it's not working:

color_table: dq 0 ; null color dq struc_color1 dq struc_color2 dq struc_color3 ; etc..., colors defined somewhere else 

now, in end:

mov rbx, 2 ; index color table mov rdi, struc_point mov rsi, qword [color_table+8*rbx] call put_pixel 

what going wrong? there no compiler errors, when run this, animations stop. rsi should contain address of struc_color, see first snippet. program works if hardcode color (mov rsi, struc_color).

this in x86_64 asm, booted directly without os.

i found problem. code wrote above in fact correct , worked well.

the problem located inside of put_pixel did not save rax. , using rax couple of lines earlier , storing data displayed in it. lead put_pixel throwing program off course on first run.