execvp usage on nasm - linux

Question

I'm learning NASM now, linux system calls probably. I'm trying to copy a process and call linux utility, but have same troubles with execvp, I don't know how to pass arguments into it. How I can do this right?
SECTION .data
cmd_cat: db '/bin/cat', 0
arg_cat: db 'log.txt', 0
cat: dd cmd_cat, arg_cat, 0
fd1: dw 0, 0
pipe_error_message: db 'pipe error occured', 0xa
pipe_error_message_length: equ $ - pipe_error_message
fork_error_message: db 'fork error occured', 0xa
fork_error_message_length: equ $ - fork_error_message
SECTION .text
GLOBAL _start:
_start:
;call pipe(fd1)
;42 - pipe system call number
mov eax, 42
mov ebx, fd1
;call kernel to execute
int 080h
cmp eax, 0
jne pipe_error
;call pipe(fd2)
mov eax, 42
mov ebx, fd1
int 080h
cmp eax, 0
jne pipe_error
;fork()
mov eax, 2
int 080h
cmp eax, -1
je fork_error
jnz child_cat
call exit
;displays error message and finishes the programm when something is wrong with pipe
pipe_error:
mov edx, pipe_error_message_length
mov ecx, pipe_error_message
call sys_write
call exit
;displays error message and finishes the programm when something is wrong with fork
fork_error:
mov edx, fork_error_message_length
mov ecx, fork_error_message
call sys_write
call exit
;sys_write(unsigned int fd, const char __user *buf, size_t count);
sys_write:
mov ebx, 1
mov eax, 4
int 080h
;exit(0)
exit:
mov eax,1
mov ebx,0
int 080h
child_cat:
mov ebx, [fd1]
mov eax, 6
int 080h
;dup2(fds[1],1)
mov ecx, 1
mov ebx, [fds + 4]
mov eax, 63
int 080h
mov eax, 11
mov ebx, cmd_cat
mov ecx, cat
int 080h

Answer 1

The following code works for me in the gas assembler. I have explained what it does, so hopefully someone else can provide the nasm translation.
.text
.global _start
_start:
movl $0xb, %eax # system call 0xb (execve) goes in eax
movl $arg0, %ebx # put the _address_ of the command string
# in ebx (we are providing a pointer)
movl $ptrarray, %ecx # put the _address_ of the array of pointers
# to arguments in ecx (again, a pointer)
movl $0, %edx # put a literal zero in edx (we don't have
# environment variables to pass, so we give
# a null pointer)
int $0x80 # run the system call
.data
ptrarray: # This is the array of pointers to command line
# arguments
.long arg0, arg1, 0 # The first element is a _pointer_ to the command
# The second element is a _pointer_ to an argument
# The third is a null pointer to indicate no more
arg0: # This is the command string
.asciz "/bin/cat"
arg1: # This is the argument string
.asciz "file.txt"