Problem 8 on Project Euler with x86 Assembly

Find the greatest product of five consecutive digits in the 1000-digit number.

73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450

My solution:

``````.text
.globl main

main:
/*-enter stack frame-*/
pushl %ebp
movl %esp, %ebp

movl \$0, %edi
loop1:
cmp \$5, %edi
je endLoop1
movl \$3, %eax
movl \$0, %ebx
movl \$buffer, %ecx
movl \$1, %edx
int \$0x80
jmp loop1
endLoop1:

/*-multiply first five, put result on esi-*/
call multiply
movl %eax, %esi

/*-keep reading until the end and keeping max product-*/
loop2:
movl \$3, %eax
movl \$0, %ebx
movl \$buffer2, %ecx
movl \$1, %edx
int \$0x80
cmp \$0, %eax
je endLoop2
movl \$buffer2, %ecx
movb (%ecx), %dl
andl \$0xFF, %edx
cmp \$10, %edx
je directJump
call moveChars
movl \$buffer, %ecx
movb %dl, (%ecx)
call multiply
cmp %esi, %eax
jg greater
jmp loop2
greater:
movl %eax, %esi
directJump:
jmp loop2
endLoop2:

/*-print result-*/
pushl %esi
pushl \$string2
call printf

/*-leave stack frame-*/
movl %ebp, %esp
popl %ebp

movl \$0, %eax
ret

moveChars:
movl \$buffer, %eax
movl (%eax), %ebx
subl \$1, %eax
movl %ebx, (%eax)
ret

multiply:
movl \$buffer, %ebx
movb (%ebx), %al
andl \$0xFF, %eax
subl \$48, %eax
movl \$4, %ecx
multiplyLoop:
cmp \$0, %ecx
je doneMultiplying