First attempt to run linux binaries. This is only the changes needed to

the generic kernel. The actual emulator is a separate LKM. (not finished
yet, sorry).
Submitted by:	sos@freebsd.org & sef@kithrup.com

18 files changed, 518 insertions, 25 deletions

diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S
index f6d6115..5d4f469 100644
--- a/sys/amd64/amd64/exception.S
+++ b/sys/amd64/amd64/exception.S
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: exception.s,v 1.6 1994/12/03 10:02:19 bde Exp $
+ *	$Id: exception.s,v 1.7 1995/01/14 13:20:05 bde Exp $
  */
 
 #include "npx.h"				/* NNPX */
@@ -245,6 +245,44 @@ IDTVEC(syscall)
 	MEXITCOUNT
 	jmp	_doreti
 
+#ifdef COMPAT_LINUX
+/*
+ * Call gate entry for Linux syscall (int 0x80)
+ */
+	SUPERALIGN_TEXT
+IDTVEC(linux_syscall)
+	pushl	$0
+	pushl	$0
+	pushal
+	pushl	%ds
+	pushl	%es
+	movl	$KDSEL,%eax
+	movl	%ax,%ds
+	movl	%ax,%es
+	FAKE_MCOUNT(12*4(%esp))
+	incl	_cnt+V_SYSCALL
+	orl	$SWI_AST_MASK,_cpl
+	call	_linux_syscall
+	/*
+	 * There was no place to save the cpl so we have to recover it
+	 * indirectly.  For traps from user mode it was 0, and for traps
+	 * from kernel mode Oring SWI_AST_MASK into it didn't change it.
+	 */
+	subl	%eax,%eax
+	testb	$SEL_RPL_MASK,TRAPF_CS_OFF(%esp)
+	jne	1f
+	movl	_cpl,%eax
+1:
+	/*
+	 * Return via _doreti to handle ASTs.  Have to change trap frame
+	 * to interrupt frame.
+	 */
+	pushl	%eax
+	subl	$4,%esp
+	MEXITCOUNT
+	jmp	_doreti
+#endif /* COMPAT_LINUX */
+
 /*
  * Include what was once config+isa-dependent code.
  * XXX it should be in a stand-alone file.  It's still icu-dependent and
diff --git a/sys/amd64/amd64/exception.s b/sys/amd64/amd64/exception.s
index f6d6115..5d4f469 100644
--- a/sys/amd64/amd64/exception.s
+++ b/sys/amd64/amd64/exception.s
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: exception.s,v 1.6 1994/12/03 10:02:19 bde Exp $
+ *	$Id: exception.s,v 1.7 1995/01/14 13:20:05 bde Exp $
  */
 
 #include "npx.h"				/* NNPX */
@@ -245,6 +245,44 @@ IDTVEC(syscall)
 	MEXITCOUNT
 	jmp	_doreti
 
+#ifdef COMPAT_LINUX
+/*
+ * Call gate entry for Linux syscall (int 0x80)
+ */
+	SUPERALIGN_TEXT
+IDTVEC(linux_syscall)
+	pushl	$0
+	pushl	$0
+	pushal
+	pushl	%ds
+	pushl	%es
+	movl	$KDSEL,%eax
+	movl	%ax,%ds
+	movl	%ax,%es
+	FAKE_MCOUNT(12*4(%esp))
+	incl	_cnt+V_SYSCALL
+	orl	$SWI_AST_MASK,_cpl
+	call	_linux_syscall
+	/*
+	 * There was no place to save the cpl so we have to recover it
+	 * indirectly.  For traps from user mode it was 0, and for traps
+	 * from kernel mode Oring SWI_AST_MASK into it didn't change it.
+	 */
+	subl	%eax,%eax
+	testb	$SEL_RPL_MASK,TRAPF_CS_OFF(%esp)
+	jne	1f
+	movl	_cpl,%eax
+1:
+	/*
+	 * Return via _doreti to handle ASTs.  Have to change trap frame
+	 * to interrupt frame.
+	 */
+	pushl	%eax
+	subl	$4,%esp
+	MEXITCOUNT
+	jmp	_doreti
+#endif /* COMPAT_LINUX */
+
 /*
  * Include what was once config+isa-dependent code.
  * XXX it should be in a stand-alone file.  It's still icu-dependent and
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index b82ecc0..3e07341 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.108 1995/02/11 04:21:24 phk Exp $
+ *	$Id: machdep.c,v 1.109 1995/02/12 09:21:04 davidg Exp $
  */
 
 #include "npx.h"
@@ -1125,6 +1125,11 @@ extern inthand_t
 	IDTVEC(page), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
 	IDTVEC(syscall);
 
+#ifdef COMPAT_LINUX
+extern inthand_t
+	IDTVEC(linux_syscall);
+#endif
+
 void
 sdtossd(sd, ssd)
 	struct segment_descriptor *sd;
@@ -1224,7 +1229,10 @@ init386(first)
 	setidt(15, &IDTVEC(rsvd),  SDT_SYS386TGT, SEL_KPL);
 	setidt(16, &IDTVEC(fpu),  SDT_SYS386TGT, SEL_KPL);
 	setidt(17, &IDTVEC(align), SDT_SYS386TGT, SEL_KPL);
-
+#ifdef COMPAT_LINUX
+ 	setidt(0x80, &IDTVEC(linux_syscall),  SDT_SYS386TGT, SEL_UPL);
+#endif
+  
 #include	"isa.h"
 #if	NISA >0
 	isa_defaultirq();
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 5adff94..f98022b 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.46 1995/02/10 06:25:14 davidg Exp $
+ *	$Id: trap.c,v 1.47 1995/02/10 06:43:47 davidg Exp $
  */
 
 /*
@@ -747,3 +747,118 @@ syscall(frame)
 		ktrsysret(p->p_tracep, code, error, rval[0]);
 #endif
 }
+
+#ifdef COMPAT_LINUX
+/*
+ * linux_syscall(frame):
+ */
+/*ARGSUSED*/
+void
+linux_syscall(frame)
+	struct trapframe frame;
+{
+	caddr_t params;
+	int i;
+	struct proc *p = curproc;
+	struct sysent *callp;
+	u_quad_t sticks;
+	int error, opc;
+	int rval[2];
+	int code;
+	struct linux_syscall_args {
+		int ebx;
+		int ecx;
+		int edx;
+		int esi;
+		int edi;
+		int ebp;
+		int eax;
+	} args;
+
+	args.ebx = frame.tf_ebx;
+	args.ecx = frame.tf_ecx;
+	args.edx = frame.tf_edx;
+	args.esi = frame.tf_esi;
+	args.edi = frame.tf_edi;
+	args.ebp = frame.tf_ebp;
+	args.eax = frame.tf_eax;
+
+	sticks = p->p_sticks;
+	if (ISPL(frame.tf_cs) != SEL_UPL)
+		panic("linux syscall");
+
+	code = frame.tf_eax;
+	p->p_md.md_regs = (int *)&frame;
+	params = (caddr_t)frame.tf_esp + sizeof (int) ;
+
+	/*
+	 * Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
+	 * THIS IS WRONG FOR LINUX  XXX SOS
+	 * SIZE OF INT 0x80 (2??) NEEDED HERE !!!
+	 */
+	opc = frame.tf_eip - 2; /* was 7 */
+	if (code == 0) {
+		code = fuword(params);
+		params += sizeof (int);
+	}
+	if (p->p_sysent->sv_mask)
+		code = code & p->p_sysent->sv_mask;
+
+	if (code < 0 || code >= p->p_sysent->sv_size)
+		callp = &p->p_sysent->sv_table[0];
+	else
+		callp = &p->p_sysent->sv_table[code];
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSCALL))
+		ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
+#endif
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSCALL))
+		ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
+#endif
+	rval[0] = 0;
+	rval[1] = frame.tf_edx;
+
+	error = (*callp->sy_call)(p, &args, rval);
+
+	switch (error) {
+
+	case 0:
+		/*
+		 * Reinitialize proc pointer `p' as it may be different
+		 * if this is a child returning from fork syscall.
+		 */
+		p = curproc;
+		frame.tf_eax = rval[0];
+		frame.tf_eflags &= ~PSL_C;	/* carry bit */
+		break;
+
+	case ERESTART:
+		frame.tf_eip = opc;
+		break;
+
+	case EJUSTRETURN:
+		break;
+
+	default:
+	bad:
+ 		if (p->p_sysent->sv_errsize)
+ 			if (error >= p->p_sysent->sv_errsize)
+  				error = -1;	/* XXX */
+   			else 
+  				error = p->p_sysent->sv_errtbl[error];
+		frame.tf_eax = -error;
+		frame.tf_eflags |= PSL_C;	/* carry bit */
+		break;
+	}
+
+	userret(p, &frame, sticks);
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSRET))
+		ktrsysret(p->p_tracep, code, error, rval[0]);
+#endif
+}
+#endif /* COMPAT_LINUX */
diff --git a/sys/amd64/include/segments.h b/sys/amd64/include/segments.h
index 6302599..0c236f5 100644
--- a/sys/amd64/include/segments.h
+++ b/sys/amd64/include/segments.h
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
- *	$Id: segments.h,v 1.6 1994/11/14 14:18:15 bde Exp $
+ *	$Id: segments.h,v 1.7 1994/11/15 14:12:40 bde Exp $
  */
 
 #ifndef _MACHINE_SEGMENTS_H_
@@ -194,7 +194,7 @@ struct region_descriptor {
  * Size of IDT table
  */
 
-#define	NIDT	48		/* 32 reserved, 16 h/w, 0 s/w */
+#define	NIDT	129		/* 32 reserved, 16 h/w, 0 s/w, linux's 0x80 */
 #define	NRSVIDT	32		/* reserved entries for cpu exceptions */
 
 /*
diff --git a/sys/i386/i386/exception.s b/sys/i386/i386/exception.s
index f6d6115..5d4f469 100644
--- a/sys/i386/i386/exception.s
+++ b/sys/i386/i386/exception.s
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: exception.s,v 1.6 1994/12/03 10:02:19 bde Exp $
+ *	$Id: exception.s,v 1.7 1995/01/14 13:20:05 bde Exp $
  */
 
 #include "npx.h"				/* NNPX */
@@ -245,6 +245,44 @@ IDTVEC(syscall)
 	MEXITCOUNT
 	jmp	_doreti
 
+#ifdef COMPAT_LINUX
+/*
+ * Call gate entry for Linux syscall (int 0x80)
+ */
+	SUPERALIGN_TEXT
+IDTVEC(linux_syscall)
+	pushl	$0
+	pushl	$0
+	pushal
+	pushl	%ds
+	pushl	%es
+	movl	$KDSEL,%eax
+	movl	%ax,%ds
+	movl	%ax,%es
+	FAKE_MCOUNT(12*4(%esp))
+	incl	_cnt+V_SYSCALL
+	orl	$SWI_AST_MASK,_cpl
+	call	_linux_syscall
+	/*
+	 * There was no place to save the cpl so we have to recover it
+	 * indirectly.  For traps from user mode it was 0, and for traps
+	 * from kernel mode Oring SWI_AST_MASK into it didn't change it.
+	 */
+	subl	%eax,%eax
+	testb	$SEL_RPL_MASK,TRAPF_CS_OFF(%esp)
+	jne	1f
+	movl	_cpl,%eax
+1:
+	/*
+	 * Return via _doreti to handle ASTs.  Have to change trap frame
+	 * to interrupt frame.
+	 */
+	pushl	%eax
+	subl	$4,%esp
+	MEXITCOUNT
+	jmp	_doreti
+#endif /* COMPAT_LINUX */
+
 /*
  * Include what was once config+isa-dependent code.
  * XXX it should be in a stand-alone file.  It's still icu-dependent and
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index b82ecc0..3e07341 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.108 1995/02/11 04:21:24 phk Exp $
+ *	$Id: machdep.c,v 1.109 1995/02/12 09:21:04 davidg Exp $
  */
 
 #include "npx.h"
@@ -1125,6 +1125,11 @@ extern inthand_t
 	IDTVEC(page), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
 	IDTVEC(syscall);
 
+#ifdef COMPAT_LINUX
+extern inthand_t
+	IDTVEC(linux_syscall);
+#endif
+
 void
 sdtossd(sd, ssd)
 	struct segment_descriptor *sd;
@@ -1224,7 +1229,10 @@ init386(first)
 	setidt(15, &IDTVEC(rsvd),  SDT_SYS386TGT, SEL_KPL);
 	setidt(16, &IDTVEC(fpu),  SDT_SYS386TGT, SEL_KPL);
 	setidt(17, &IDTVEC(align), SDT_SYS386TGT, SEL_KPL);
-
+#ifdef COMPAT_LINUX
+ 	setidt(0x80, &IDTVEC(linux_syscall),  SDT_SYS386TGT, SEL_UPL);
+#endif
+  
 #include	"isa.h"
 #if	NISA >0
 	isa_defaultirq();
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 5adff94..f98022b 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.46 1995/02/10 06:25:14 davidg Exp $
+ *	$Id: trap.c,v 1.47 1995/02/10 06:43:47 davidg Exp $
  */
 
 /*
@@ -747,3 +747,118 @@ syscall(frame)
 		ktrsysret(p->p_tracep, code, error, rval[0]);
 #endif
 }
+
+#ifdef COMPAT_LINUX
+/*
+ * linux_syscall(frame):
+ */
+/*ARGSUSED*/
+void
+linux_syscall(frame)
+	struct trapframe frame;
+{
+	caddr_t params;
+	int i;
+	struct proc *p = curproc;
+	struct sysent *callp;
+	u_quad_t sticks;
+	int error, opc;
+	int rval[2];
+	int code;
+	struct linux_syscall_args {
+		int ebx;
+		int ecx;
+		int edx;
+		int esi;
+		int edi;
+		int ebp;
+		int eax;
+	} args;
+
+	args.ebx = frame.tf_ebx;
+	args.ecx = frame.tf_ecx;
+	args.edx = frame.tf_edx;
+	args.esi = frame.tf_esi;
+	args.edi = frame.tf_edi;
+	args.ebp = frame.tf_ebp;
+	args.eax = frame.tf_eax;
+
+	sticks = p->p_sticks;
+	if (ISPL(frame.tf_cs) != SEL_UPL)
+		panic("linux syscall");
+
+	code = frame.tf_eax;
+	p->p_md.md_regs = (int *)&frame;
+	params = (caddr_t)frame.tf_esp + sizeof (int) ;
+
+	/*
+	 * Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
+	 * THIS IS WRONG FOR LINUX  XXX SOS
+	 * SIZE OF INT 0x80 (2??) NEEDED HERE !!!
+	 */
+	opc = frame.tf_eip - 2; /* was 7 */
+	if (code == 0) {
+		code = fuword(params);
+		params += sizeof (int);
+	}
+	if (p->p_sysent->sv_mask)
+		code = code & p->p_sysent->sv_mask;
+
+	if (code < 0 || code >= p->p_sysent->sv_size)
+		callp = &p->p_sysent->sv_table[0];
+	else
+		callp = &p->p_sysent->sv_table[code];
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSCALL))
+		ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
+#endif
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSCALL))
+		ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
+#endif
+	rval[0] = 0;
+	rval[1] = frame.tf_edx;
+
+	error = (*callp->sy_call)(p, &args, rval);
+
+	switch (error) {
+
+	case 0:
+		/*
+		 * Reinitialize proc pointer `p' as it may be different
+		 * if this is a child returning from fork syscall.
+		 */
+		p = curproc;
+		frame.tf_eax = rval[0];
+		frame.tf_eflags &= ~PSL_C;	/* carry bit */
+		break;
+
+	case ERESTART:
+		frame.tf_eip = opc;
+		break;
+
+	case EJUSTRETURN:
+		break;
+
+	default:
+	bad:
+ 		if (p->p_sysent->sv_errsize)
+ 			if (error >= p->p_sysent->sv_errsize)
+  				error = -1;	/* XXX */
+   			else 
+  				error = p->p_sysent->sv_errtbl[error];
+		frame.tf_eax = -error;
+		frame.tf_eflags |= PSL_C;	/* carry bit */
+		break;
+	}
+
+	userret(p, &frame, sticks);
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSRET))
+		ktrsysret(p->p_tracep, code, error, rval[0]);
+#endif
+}
+#endif /* COMPAT_LINUX */
diff --git a/sys/i386/include/segments.h b/sys/i386/include/segments.h
index 6302599..0c236f5 100644
--- a/sys/i386/include/segments.h
+++ b/sys/i386/include/segments.h
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
- *	$Id: segments.h,v 1.6 1994/11/14 14:18:15 bde Exp $
+ *	$Id: segments.h,v 1.7 1994/11/15 14:12:40 bde Exp $
  */
 
 #ifndef _MACHINE_SEGMENTS_H_
@@ -194,7 +194,7 @@ struct region_descriptor {
  * Size of IDT table
  */
 
-#define	NIDT	48		/* 32 reserved, 16 h/w, 0 s/w */
+#define	NIDT	129		/* 32 reserved, 16 h/w, 0 s/w, linux's 0x80 */
 #define	NRSVIDT	32		/* reserved entries for cpu exceptions */
 
 /*
diff --git a/sys/kern/imgact_aout.c b/sys/kern/imgact_aout.c
index c700c26..5d6454c 100644
--- a/sys/kern/imgact_aout.c
+++ b/sys/kern/imgact_aout.c
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: imgact_aout.c,v 1.8 1994/09/24 21:36:50 davidg Exp $
+ *	$Id: imgact_aout.c,v 1.9 1994/09/25 19:33:31 phk Exp $
  */
 
 #include <sys/param.h>
@@ -54,6 +54,16 @@ exec_aout_imgact(iparams)
 	int error;
 	extern struct sysentvec aout_sysvec;
 
+#ifdef COMPAT_LINUX
+	/*
+	 * Linux and *BSD binaries look very much alike,
+	 * only the machine id is different: 
+	 * 0x64 for Linux, 0x86 for *BSD.
+	 */
+	if (((a_out->a_magic >> 16) & 0xff) != 0x86)
+		return -1;
+#endif /* COMPAT_LINUX */
+
 	/*
 	 * Set file/virtual offset based on a.out variant.
 	 *	We do two cases: host byte order and network byte order
diff --git a/sys/kern/init_sysent.c b/sys/kern/init_sysent.c
index 8c68240..bd77750 100644
--- a/sys/kern/init_sysent.c
+++ b/sys/kern/init_sysent.c
@@ -2,7 +2,7 @@
  * System call switch table.
  *
  * DO NOT EDIT-- this file is automatically generated.
- * created from	$Id: syscalls.master,v 1.11 1994/10/02 04:45:52 davidg Exp $
+ * created from	$Id: syscalls.master,v 1.12 1994/12/14 17:57:23 wollman Exp $
  */
 
 #include <sys/param.h>
@@ -520,5 +520,6 @@ struct sysentvec aout_sysvec = {
 	0,
 	0,
 	0,
+	0,
 	0
 };
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index b35343b..94b5dc2 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: kern_exec.c,v 1.10 1994/10/02 17:35:13 phk Exp $
+ *	$Id: kern_exec.c,v 1.11 1995/01/09 16:04:49 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -46,6 +46,7 @@
 #include <sys/wait.h>
 #include <sys/mman.h>
 #include <sys/malloc.h>
+#include <sys/sysent.h>
 #include <sys/syslog.h>
 #include <sys/shm.h>
 
@@ -214,9 +215,14 @@ interpret:
 	p->p_vmspace->vm_minsaddr = (char *)stack_base;
 
 	/*
-	 * Stuff argument count as first item on stack
+	 * If custom stack fixup routine present for this process
+	 * let it do the stack setup.
+	 * Else stuff argument count as first item on stack
 	 */
-	*(--stack_base) = iparams->argc;
+	if (p->p_sysent->sv_fixup)
+		(*p->p_sysent->sv_fixup)(&stack_base, iparams);
+	else
+		*(--stack_base) = iparams->argc;
 
 	/* close files on exec */
 	fdcloseexec(p);
diff --git a/sys/kern/makesyscalls.sh b/sys/kern/makesyscalls.sh
index 50de7d2..a4875fb 100644
--- a/sys/kern/makesyscalls.sh
+++ b/sys/kern/makesyscalls.sh
@@ -1,6 +1,6 @@
 #! /bin/sh -
 #	@(#)makesyscalls.sh	8.1 (Berkeley) 6/10/93
-# $Id: makesyscalls.sh,v 1.9 1994/10/09 22:07:37 sos Exp $
+# $Id: makesyscalls.sh,v 1.10 1994/11/06 21:57:16 ats Exp $
 
 set -e
 
@@ -183,7 +183,7 @@ awk < $1 "
 		printf ("struct sysentvec aout_sysvec = {\n") > sysent
 		printf ("\tsizeof (sysent) / sizeof (sysent[0]),\n") > sysent
 		printf ("\tsysent,\n") > sysent
-		printf ("\t0,\n\t0,\n\t0,\n\t0,\n\t0\n};\n") > sysent
+		printf ("\t0,\n\t0,\n\t0,\n\t0,\n\t0,\n\t0\n};\n") > sysent
 		printf("};\n") > sysnames
 	} '
 
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 5adff94..f98022b 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.46 1995/02/10 06:25:14 davidg Exp $
+ *	$Id: trap.c,v 1.47 1995/02/10 06:43:47 davidg Exp $
  */
 
 /*
@@ -747,3 +747,118 @@ syscall(frame)
 		ktrsysret(p->p_tracep, code, error, rval[0]);
 #endif
 }
+
+#ifdef COMPAT_LINUX
+/*
+ * linux_syscall(frame):
+ */
+/*ARGSUSED*/
+void
+linux_syscall(frame)
+	struct trapframe frame;
+{
+	caddr_t params;
+	int i;
+	struct proc *p = curproc;
+	struct sysent *callp;
+	u_quad_t sticks;
+	int error, opc;
+	int rval[2];
+	int code;
+	struct linux_syscall_args {
+		int ebx;
+		int ecx;
+		int edx;
+		int esi;
+		int edi;
+		int ebp;
+		int eax;
+	} args;
+
+	args.ebx = frame.tf_ebx;
+	args.ecx = frame.tf_ecx;
+	args.edx = frame.tf_edx;
+	args.esi = frame.tf_esi;
+	args.edi = frame.tf_edi;
+	args.ebp = frame.tf_ebp;
+	args.eax = frame.tf_eax;
+
+	sticks = p->p_sticks;
+	if (ISPL(frame.tf_cs) != SEL_UPL)
+		panic("linux syscall");
+
+	code = frame.tf_eax;
+	p->p_md.md_regs = (int *)&frame;
+	params = (caddr_t)frame.tf_esp + sizeof (int) ;
+
+	/*
+	 * Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
+	 * THIS IS WRONG FOR LINUX  XXX SOS
+	 * SIZE OF INT 0x80 (2??) NEEDED HERE !!!
+	 */
+	opc = frame.tf_eip - 2; /* was 7 */
+	if (code == 0) {
+		code = fuword(params);
+		params += sizeof (int);
+	}
+	if (p->p_sysent->sv_mask)
+		code = code & p->p_sysent->sv_mask;
+
+	if (code < 0 || code >= p->p_sysent->sv_size)
+		callp = &p->p_sysent->sv_table[0];
+	else
+		callp = &p->p_sysent->sv_table[code];
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSCALL))
+		ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
+#endif
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSCALL))
+		ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
+#endif
+	rval[0] = 0;
+	rval[1] = frame.tf_edx;
+
+	error = (*callp->sy_call)(p, &args, rval);
+
+	switch (error) {
+
+	case 0:
+		/*
+		 * Reinitialize proc pointer `p' as it may be different
+		 * if this is a child returning from fork syscall.
+		 */
+		p = curproc;
+		frame.tf_eax = rval[0];
+		frame.tf_eflags &= ~PSL_C;	/* carry bit */
+		break;
+
+	case ERESTART:
+		frame.tf_eip = opc;
+		break;
+
+	case EJUSTRETURN:
+		break;
+
+	default:
+	bad:
+ 		if (p->p_sysent->sv_errsize)
+ 			if (error >= p->p_sysent->sv_errsize)
+  				error = -1;	/* XXX */
+   			else 
+  				error = p->p_sysent->sv_errtbl[error];
+		frame.tf_eax = -error;
+		frame.tf_eflags |= PSL_C;	/* carry bit */
+		break;
+	}
+
+	userret(p, &frame, sticks);
+
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_SYSRET))
+		ktrsysret(p->p_tracep, code, error, rval[0]);
+#endif
+}
+#endif /* COMPAT_LINUX */
diff --git a/sys/kern/syscalls.c b/sys/kern/syscalls.c
index 247b928..d880f18 100644
--- a/sys/kern/syscalls.c
+++ b/sys/kern/syscalls.c
@@ -2,7 +2,7 @@
  * System call names.
  *
  * DO NOT EDIT-- this file is automatically generated.
- * created from	$Id: syscalls.master,v 1.11 1994/10/02 04:45:52 davidg Exp $
+ * created from	$Id: syscalls.master,v 1.12 1994/12/14 17:57:23 wollman Exp $
  */
 
 char *syscallnames[] = {
diff --git a/sys/sys/syscall-hide.h b/sys/sys/syscall-hide.h
index b40f3d9..3447f9c 100644
--- a/sys/sys/syscall-hide.h
+++ b/sys/sys/syscall-hide.h
@@ -2,7 +2,7 @@
  * System call hiders.
  *
  * DO NOT EDIT-- this file is automatically generated.
- * created from	$Id: syscalls.master,v 1.11 1994/10/02 04:45:52 davidg Exp $
+ * created from	$Id: syscalls.master,v 1.12 1994/12/14 17:57:23 wollman Exp $
  */
 
 HIDE_POSIX(fork)
diff --git a/sys/sys/syscall.h b/sys/sys/syscall.h
index ab6178c..8ebc58f 100644
--- a/sys/sys/syscall.h
+++ b/sys/sys/syscall.h
@@ -2,7 +2,7 @@
  * System call numbers.
  *
  * DO NOT EDIT-- this file is automatically generated.
- * created from	$Id: syscalls.master,v 1.11 1994/10/02 04:45:52 davidg Exp $
+ * created from	$Id: syscalls.master,v 1.12 1994/12/14 17:57:23 wollman Exp $
  */
 
 #define	SYS_syscall	0
diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
index 8a0d939..64ac5bb 100644
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: sysent.h,v 1.1 1994/08/24 11:47:23 sos Exp $
+ *	$Id: sysent.h,v 1.2 1994/10/09 21:53:05 sos Exp $
  */
 
 #ifndef _SYS_SYSENT_H_
@@ -49,6 +49,7 @@ struct sysentvec {
 	int		*sv_sigtbl;	/* signal translation table */
 	int		sv_errsize;	/* size of signal translation table */
 	int 		*sv_errtbl;	/* errno translation table */
+	int		(*sv_fixup)();	/* stack fixup function */
 };
 
 #ifdef KERNEL