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.code16gcc
.globl _start
_start:
/* Make sure stack pointer is normalized */
movzwl %sp,%esp
/* Zero .bss */
movw $__bss_start,%di
xorl %eax,%eax
movw $(_end+3),%cx
subw %di,%cx
shrw $2,%cx
cld
rep ; stosl
/* Normalize the command line. At startup 0x80 = length and
the command line starts at 0x81, but with whitespace */
movl $0x81,%esi
movzbl (0x80),%ebx
movb $0,(%bx,%si) /* Null-terminate the string */
1:
lodsb
dec %al /* Stop on null */
cmp $31,%al /* Whitespace? */
jbe 1
dec %si /* Unskip first character */
/* Invoke _cstart */
pushl %esi /* Pointer to command line */
calll _cstart
/* Terminate program (with error code in %al) */
movb $0x4c,%ah
int $0x21
hlt
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