diff options
Diffstat (limited to 'dos/crt0.S')
| -rw-r--r-- | dos/crt0.S | 29 |
1 files changed, 23 insertions, 6 deletions
@@ -4,27 +4,38 @@ # error "This file assumes -mregparm=3 -DREGPARM=3" #endif - .section ".init","ax" + .section ".text","ax" .globl _start .type _start,@function _start: # Align the stack and make sure the high half is zero andl $0xfff8,%esp + # DS, ES points to the PSP at this point + pushw %es # Save PSP pointer + movw %cs,%ax + movw %ax,%ds + movw %ax,%es + # Clear the .bss cld xorl %eax,%eax movw $__bss_start,%di - movw $_end+3,%cx + movw $__bss_end+3,%cx subw %di,%cx shrw $2,%cx rep ; stosl + # Copy the command line into our own segment + popw %fs # FS -> PSP + movw $_cmdline,%di + movzbw %fs:0x80,%cx + movw $0x81,%si + fs ; rep ; movsb + # Already zero-terminated since we're writing into clean bss + # Compute argc and argv (assumes REGPARM) - xorl %edx,%edx - movzbw 0x80,%bx - movb %dl,0x81(%bx) # Zero-terminate string - movb $0x81,%dl + movl $_cmdline,%edx pushl %eax # Make space for argv movl %esp,%eax calll __parse_argv @@ -51,3 +62,9 @@ exit: 1: hlt jmp 1b .size exit,.-exit + + .section ".bss","aw" + .balign 4 +_cmdline: + .space 128 + .size _cmdline,.-_cmdline |