>I noticed that NEWS5000 doesn't boot with current source.
>It works fine with 1.4ZD built on Jun 13.
>Do you have any idea what is wrong?

This patch seems to work for me.
I think these cache flushes are not needed because sys_execve() does
pmap_procwr() for the same region, but I'm not sure...

*** mips_machdep.c~	Mon Jul 24 18:32:37 2000
--- mips_machdep.c	Thu Jul 27 16:09:26 2000
***************
*** 662,670 ****
--- 662,673 ----
  	struct exec_package *pack;
  	u_long stack;
  {
+ #if 0
  	int szsigcode = pack->ep_emul->e_esigcode - pack->ep_emul->e_sigcode;
+ #endif
  	struct frame *f = (struct frame *)p->p_md.md_regs;
  
+ #if 0
  	/*
  	 * Make sure sigreturn trampoline is coherent.
  	 */
***************
*** 673,678 ****
--- 676,682 ----
  		MachFlushDCache((vaddr_t)p->p_sigacts->ps_sigcode, szsigcode);
  #endif
  	MachFlushICache((vaddr_t)p->p_sigacts->ps_sigcode, szsigcode);
+ #endif
  
  	memset(f, 0, sizeof(struct frame));
  	f->f_regs[SP] = (int) stack;