#include "syscall.h" DEFINE(__brk) cmpl 4(ap),Imin bgeq Iok movl Imin,4(ap) Iok: chmk $17 bcs Ierr movl 4(ap),Icur clrl r0 ret Ierr: jmp cerror DEFINE(__sbrk) addl3 Icur,4(ap),-(sp) bcs Ierr pushl $1 movl ap,r3 movl sp,ap chmk $17 bcs Ierr movl Icur,r0 addl2 4(r3),Icur ret .sect .data Imin: .data4 endbss Icur: .data4 endbss