Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

===================================================================
RCS file: /ftp/cvs/cvsroot/src/sys/arch/i386/i386/locore.S,v
rcsdiff: /ftp/cvs/cvsroot/src/sys/arch/i386/i386/locore.S,v: warning: Unknown phrases like `commitid ...;' are present.
retrieving revision 1.132
retrieving revision 1.150
diff -u -p -r1.132 -r1.150
--- src/sys/arch/i386/i386/locore.S	2016/07/01 13:11:21	1.132
+++ src/sys/arch/i386/i386/locore.S	2017/08/10 14:13:45	1.150
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.S,v 1.132 2016/07/01 13:11:21 maxv Exp $	*/
+/*	$NetBSD: locore.S,v 1.150 2017/08/10 14:13:45 maxv Exp $	*/
 
 /*
  * Copyright-o-rama!
@@ -128,9 +128,8 @@
  */
 
 #include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: locore.S,v 1.132 2016/07/01 13:11:21 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: locore.S,v 1.150 2017/08/10 14:13:45 maxv Exp $");
 
-#include "opt_compat_oldboot.h"
 #include "opt_copy_symtab.h"
 #include "opt_ddb.h"
 #include "opt_modular.h"
@@ -270,45 +269,6 @@ __KERNEL_RCSID(0, "$NetBSD: locore.S,v 1
  */
 	.data
 
-	.globl	_C_LABEL(lapic_tpr)
-
-#if NLAPIC > 0
-#ifdef __ELF__
-	.align	PAGE_SIZE
-#else
-	.align	12
-#endif
-	.globl	_C_LABEL(local_apic)
-	.globl	_C_LABEL(lapic_id)
-
-	.type	_C_LABEL(local_apic), @object
-LABEL(local_apic)
-	.space	LAPIC_ID
-END(local_apic)
-	.type	_C_LABEL(lapic_id), @object
-LABEL(lapic_id)
-	.long	0x00000000
-	.space	LAPIC_TPRI-(LAPIC_ID+4)
-END(lapic_id)
-	.type	_C_LABEL(lapic_tpr), @object
-LABEL(lapic_tpr)
-	.space	LAPIC_PPRI-LAPIC_TPRI
-END(lapic_tpr)
-	.type	_C_LABEL(lapic_ppr), @object
-_C_LABEL(lapic_ppr):
-	.space	LAPIC_ISR-LAPIC_PPRI
-END(lapic_ppr)
-	.type	_C_LABEL(lapic_isr), @object
-_C_LABEL(lapic_isr):
-	.space	PAGE_SIZE-LAPIC_ISR
-END(lapic_isr)
-#else
-	.type	_C_LABEL(lapic_tpr), @object
-LABEL(lapic_tpr)
-	.long 0
-END(lapic_tpr)
-#endif
-
 	.globl	_C_LABEL(tablesize)
 	.globl	_C_LABEL(nox_flag)
 	.globl	_C_LABEL(cputype)
@@ -382,11 +342,13 @@ _C_LABEL(Multiboot_Header):
 	jne	1f
 
 	/*
-	 * Indeed, a multiboot-compliant boot loader executed us.  We copy
-	 * the received Multiboot information structure into kernel's data
-	 * space to process it later -- after we are relocated.  It will
-	 * be safer to run complex C code than doing it at this point.
+	 * Indeed, a multiboot-compliant boot loader executed us. We switch
+	 * to the temporary stack, and copy the received Multiboot information
+	 * structure into kernel's data space to process it later -- after we
+	 * are relocated. It will be safer to run complex C code than doing it
+	 * at this point.
 	 */
+	movl	$_RELOC(tmpstk),%esp
 	pushl	%ebx		/* Address of Multiboot information */
 	call	_C_LABEL(multiboot_pre_reloc)
 	addl	$4,%esp
@@ -640,7 +602,7 @@ no_NOX:
  */
 
 	/* Find end of kernel image; brings us on (1). */
-	movl	$RELOC(end),%edi
+	movl	$RELOC(__kernel_end),%edi
 
 #if (NKSYMS || defined(DDB) || defined(MODULAR)) && !defined(makeoptions_COPY_SYMTAB)
 	/* Save the symbols (if loaded); brinds us on (2). */
@@ -672,7 +634,7 @@ no_NOX:
 	incl	%eax		/* one more PTP for VAs stolen by bootstrap */
 1:	movl	%eax,RELOC(nkptp)+1*4
 
-	/* tablesize = (PDP_SIZE + UPAGES + nkptp) << PGSHIFT; */
+	/* tablesize = (PDP_SIZE + UPAGES + nkptp[1]) << PGSHIFT; */
 	addl	$(PDP_SIZE+UPAGES),%eax
 #ifdef PAE
 	incl	%eax 		/* one more page for L3 */
@@ -682,7 +644,8 @@ no_NOX:
 #endif
 	movl	%eax,RELOC(tablesize)
 
-	/* Ensure that nkptp covers BOOTSTRAP TABLES. */
+	/* Ensure that nkptp[1] covers BOOTSTRAP TABLES, ie:
+	 * (esi + tablesize) >> L2_SHIFT + 1 < nkptp[1] */
 	addl	%esi,%eax
 	addl	$~L2_FRAME,%eax
 	shrl	$L2_SHIFT,%eax
@@ -709,7 +672,7 @@ no_NOX:
 	 */
 	leal	(PROC0_PTP1_OFF)(%esi),%ebx
 
-	/* Skip the first MB. */
+	/* Skip the area below the kernel text. */
 	movl	$(KERNTEXTOFF - KERNBASE),%ecx
 	shrl	$PGSHIFT,%ecx
 	fillkpt_blank
@@ -738,13 +701,13 @@ no_NOX:
 	orl	$(PG_V|PG_KW),%eax
 	fillkpt_nox
 
-	/* Map [SYMS]+[PRELOADED MODULES] RWX. */
+	/* Map [SYMS]+[PRELOADED MODULES] RW. */
 	movl	$RELOC(__kernel_end),%eax
 	movl	%esi,%ecx		/* start of BOOTSTRAP TABLES */
 	subl	%eax,%ecx
 	shrl	$PGSHIFT,%ecx
 	orl	$(PG_V|PG_KW),%eax
-	fillkpt
+	fillkpt_nox
 
 	/* Map the BOOTSTRAP TABLES RW. */
 	movl	%esi,%eax		/* start of BOOTSTRAP TABLES */
@@ -776,12 +739,12 @@ no_NOX:
 	movl	RELOC(nkptp)+1*4,%ecx
 	fillkpt
 
-	/* Install a PDE recursively mapping page directory as a page table! */
+	/* Install recursive top level PDE */
 	leal	(PROC0_PDIR_OFF + PDIR_SLOT_PTE * PDE_SIZE)(%esi),%ebx
 	leal	(PROC0_PDIR_OFF)(%esi),%eax
 	orl	$(PG_V|PG_KW),%eax
 	movl	$PDP_SIZE,%ecx
-	fillkpt
+	fillkpt_nox
 
 #ifdef PAE
 	/*
@@ -876,28 +839,10 @@ begin:
 	pushl	$0	/* init386() expects a 64 bits paddr_t with PAE */
 #endif
 	pushl	%eax
-	call	_C_LABEL(init386)	/* wire 386 chip for unix operation */
+	call	_C_LABEL(init386)
 	addl	$PDE_SIZE,%esp		/* pop paddr_t */
 	addl	$NGDT*8,%esp		/* pop temporary gdt */
 
-#ifdef SAFARI_FIFO_HACK
-	movb	$5,%al
-	movw	$0x37b,%dx
-	outb	%al,%dx
-	movw	$0x37f,%dx
-	inb	%dx,%al
-	movb	%al,%cl
-
-	orb	$1,%cl
-
-	movb	$5,%al
-	movw	$0x37b,%dx
-	outb	%al,%dx
-	movw	$0x37f,%dx
-	movb	%cl,%al
-	outb	%al,%dx
-#endif /* SAFARI_FIFO_HACK */
-
 	call 	_C_LABEL(main)
 #else /* XEN */
 	/* First, reset the PSL. */
@@ -905,62 +850,67 @@ begin:
 	popfl
 
 	cld
-	movl	%esp, %ebx		/* save start of available space */
-	movl	$_RELOC(tmpstk),%esp	/* bootstrap stack end location */
+
+	/*
+	 * Xen info:
+	 * - %esp -> stack, *theoretically* the last used page by Xen bootstrap
+	 */
+	movl	%esp,%ebx
+	movl	$_RELOC(tmpstk),%esp
 
 	/* Clear BSS. */
 	xorl	%eax,%eax
 	movl	$RELOC(__bss_start),%edi
 	movl	$RELOC(_end),%ecx
 	subl	%edi,%ecx
-	rep stosb
+	rep
+	stosb
 
 	/* Copy the necessary stuff from start_info structure. */
 	/* We need to copy shared_info early, so that sti/cli work */
 	movl	$RELOC(start_info_union),%edi
 	movl	$128,%ecx
-	rep movsl
+	rep
+	movsl
 
-	/* Clear segment registers; always null in proc0. */
+	/* Clear segment registers. */
 	xorl	%eax,%eax
 	movw	%ax,%fs
 	movw	%ax,%gs
-	decl	%eax
-	movl	%eax,RELOC(cpuid_level)
 
 	xorl	%eax,%eax
 	cpuid
 	movl	%eax,RELOC(cpuid_level)
 
 	/*
-	 * Use a temp page. We'll re- add it to uvm(9) once we're
-	 * done using it.
+	 * Use a temporary GDT page. We'll re-add it to uvm(9) once we're done
+	 * using it.
 	 */
-	movl	$RELOC(tmpgdt), %eax
+	movl	$RELOC(tmpgdt),%eax
 	pushl	%eax		/* start of temporary gdt */
 	call	_C_LABEL(initgdt)
 	addl	$4,%esp
 
-	call	xen_pmap_bootstrap
+	call	xen_locore
 
 	/*
-	 * First avail returned by xen_pmap_bootstrap in %eax
+	 * The first VA available is returned by xen_locore in %eax. We
+	 * use it as the UAREA, and set up the stack here.
 	 */
-	movl	%eax, %esi;
-	movl	%esi, _C_LABEL(lwp0uarea)
-
-	/* Set up bootstrap stack. */
+	movl	%eax,%esi
+	movl	%esi,_C_LABEL(lwp0uarea)
 	leal	(USPACE-FRAMESIZE)(%eax),%esp
 	xorl	%ebp,%ebp		/* mark end of frames */
 
-	addl	$USPACE, %esi
-	subl	$KERNBASE, %esi		/* init386 wants a physical address */
+	/* Set first_avail after the DUMMY PAGE (see xen_locore). */
+	addl	$(USPACE+PAGE_SIZE),%esi
+	subl	$KERNBASE,%esi		/* init386 wants a physical address */
 
 #ifdef PAE
 	pushl	$0	/* init386() expects a 64 bits paddr_t with PAE */
 #endif
 	pushl	%esi
-	call	_C_LABEL(init386)	/* wire 386 chip for unix operation */
+	call	_C_LABEL(init386)
 	addl	$PDE_SIZE,%esp		/* pop paddr_t */
 	call 	_C_LABEL(main)
 #endif /* XEN */
@@ -1191,14 +1141,25 @@ skip_save:
 	/* Is this process using RAS (restartable atomic sequences)? */
 	movl	L_PROC(%edi),%eax
 	cmpl	$0,P_RASLIST(%eax)
-	jne	5f
+	je	no_RAS
+
+	/* Handle restartable atomic sequences (RAS). */
+	movl	L_MD_REGS(%edi),%ecx
+	pushl	TF_EIP(%ecx)
+	pushl	%eax
+	call	_C_LABEL(ras_lookup)
+	addl	$8,%esp
+	cmpl	$-1,%eax
+	je	no_RAS
+	movl	L_MD_REGS(%edi),%ecx
+	movl	%eax,TF_EIP(%ecx)
+no_RAS:
 
 	/*
 	 * Restore cr0 (including FPU state).  Raise the IPL to IPL_HIGH.
 	 * FPU IPIs can alter the LWP's saved cr0.  Dropping the priority
 	 * is deferred until mi_switch(), when cpu_switchto() returns.
 	 */
-2:
 #ifdef XEN
 	pushl	%edi
 	call	_C_LABEL(i386_tls_switch)
@@ -1231,18 +1192,6 @@ switch_return:
 	popl	%ebx
 	ret
 
-	/* Check for restartable atomic sequences (RAS). */
-5:	movl	L_MD_REGS(%edi),%ecx
-	pushl	TF_EIP(%ecx)
-	pushl	%eax
-	call	_C_LABEL(ras_lookup)
-	addl	$8,%esp
-	cmpl	$-1,%eax
-	je	2b
-	movl	L_MD_REGS(%edi),%ecx
-	movl	%eax,TF_EIP(%ecx)
-	jmp	2b
-
 .Lcopy_iobitmap:
 	/* Copy I/O bitmap. */
 	incl	_C_LABEL(pmap_iobmp_evcnt)+EV_COUNT
@@ -1273,30 +1222,12 @@ ENTRY(savectx)
 END(savectx)
 
 /*
- * osyscall()
- *
- * Old call gate entry for syscall
- */
-IDTVEC(osyscall)
-#ifndef XEN
-	/* XXX we are in trouble! interrupts be off here. */
-	cli			/* must be first instruction */
-#endif
-	pushfl			/* set eflags in trap frame */
-	popl	8(%esp)
-	orl	$PSL_I,8(%esp)	/* re-enable ints on return to user */
-	pushl	$7		/* size of instruction for restart */
-	jmp	syscall1
-IDTVEC_END(osyscall)
-
-/*
  * syscall()
  *
  * Trap gate entry for syscall
  */
 IDTVEC(syscall)
 	pushl	$2		/* size of instruction for restart */
-syscall1:
 	pushl	$T_ASTFLT	/* trap # for doing ASTs */
 	INTRENTRY
 	STI(%eax)
@@ -1383,39 +1314,6 @@ syscall1:
 	jmp	.Lsyscall_checkast	/* re-check ASTs */
 IDTVEC_END(syscall)
 
-IDTVEC(svr4_fasttrap)
-	pushl	$2		/* size of instruction for restart */
-	pushl	$T_ASTFLT	/* trap # for doing ASTs */
-	INTRENTRY
-	STI(%eax)
-	pushl	$RW_READER
-	pushl	$_C_LABEL(svr4_fasttrap_lock)
-	call	_C_LABEL(rw_enter)
-	addl	$8,%esp
-	call	*_C_LABEL(svr4_fasttrap_vec)
-	pushl	$_C_LABEL(svr4_fasttrap_lock)
-	call	_C_LABEL(rw_exit)
-	addl	$4,%esp
-2:	/* Check for ASTs on exit to user mode. */
-	cli
-	CHECK_ASTPENDING(%eax)
-	je	1f
-	/* Always returning to user mode here. */
-	CLEAR_ASTPENDING(%eax)
-	sti
-	/* Pushed T_ASTFLT into tf_trapno on entry. */
-	pushl	%esp
-	call	_C_LABEL(trap)
-	addl	$4,%esp
-	jmp	2b
-1:	CHECK_DEFERRED_SWITCH
-	jnz	9f
-	INTRFASTEXIT
-9:	sti
-	call	_C_LABEL(pmap_load)
-	cli
-	jmp	2b
-
 /*
  * int npx586bug1(int a, int b)
  * Used when checking for the FDIV bug on first generations pentiums.