Add our doscmd to the tree. This is a result of work from BSDI, and

a group of dos emulator developers.
Submitted by:	Jonathan Lemon <jlemon@americantv.com>
Obtained from:	BSDI

1 files changed, 139 insertions, 0 deletions

diff --git a/usr.bin/doscmd/int.c b/usr.bin/doscmd/int.c
new file mode 100644
index 0000000..2385f56
--- /dev/null
+++ b/usr.bin/doscmd/int.c
@@ -0,0 +1,139 @@
+/*
+** No copyright?!
+**
+** $Id: int.c,v 1.4 1997/03/18 02:36:56 msmith Exp $
+*/
+#include "doscmd.h"
+
+/*
+** Cause a software interrupt to happen immediately after we
+** return to vm86 mode
+*/
+void
+softint(int intnum)
+{
+    regcontext_t	*REGS = saved_regcontext;
+    u_long vec = ivec[intnum];
+
+    /*
+    ** if we're dead, or there's no vector or the saved registers are
+    ** invalid
+    */
+    if (dead || !saved_valid || vec == 0)
+	return;
+
+    /* 
+    ** if the vector points into the BIOS, or the handler at the other
+    ** end is just an IRET, don't bother.
+    */
+    if ((vec >> 16) == 0xf000 || *(u_char *)VECPTR(vec) == 0xcf)
+	return;
+
+#if 0
+    /*
+     * software interrupts are always taken
+     */
+    if ((R_EFLAGS & PSL_VIF) == 0) {
+        delay_interrupt(intnum, softint);
+        return;
+    }
+#endif
+
+    debug(D_TRAPS|intnum, "Int%x [%04x:%04x]\n", 
+	  intnum, vec >> 16, vec & 0xffff);
+
+    N_PUSH((R_FLAGS & ~PSL_I) | (R_EFLAGS & PSL_VIF ? PSL_I : 0), REGS);
+    N_PUSH(R_CS, REGS);
+    N_PUSH(R_IP, REGS);
+#if 1
+    R_EFLAGS &= ~PSL_VIF;		/* XXX disable interrupts? */
+#else
+    R_EFLAGS |= PSL_VIF;
+#endif
+    N_PUTVEC(R_CS, R_IP, vec);
+}
+
+/*
+** Cause a hardware interrupt to happen immediately after
+** we return to vm86 mode
+*/
+void
+hardint(int intnum)
+{
+    regcontext_t	*REGS = saved_regcontext;
+    u_long vec = ivec[intnum];
+
+    /*
+     * XXXXX
+     * We should simulate the IRQ mask in the PIC.
+     */
+	
+	/* 
+	** if we're dead, or there's no vector, or the saved registers
+	** are invalid
+	*/
+	if (dead || !saved_valid || vec == 0)
+	    return;
+	
+	/* 
+	** if the vector points into the BIOS, or the handler at the
+	** other end is just an IRET, don't bother 
+	*/
+	if ((vec >> 16) == 0xf000 || *(u_char *)VECPTR(vec) == 0xcf)
+	    return;
+
+     if ((R_EFLAGS & PSL_VIF) == 0) {
+         delay_interrupt(intnum, hardint);
+         return;
+     }
+	
+	debug(D_TRAPS|intnum, "Int%x [%04x:%04x]\n",
+	      intnum, vec >> 16, vec & 0xffff);
+
+        N_PUSH((R_FLAGS & ~PSL_I) | (R_EFLAGS & PSL_VIF ? PSL_I : 0), REGS);
+	N_PUSH(R_CS, REGS);
+	N_PUSH(R_IP, REGS);
+#if 1
+	R_EFLAGS &= ~PSL_VIF;		/* XXX disable interrupts */
+#else
+        R_EFLAGS |= PSL_VIF;
+#endif
+	N_PUTVEC(R_CS, R_IP, vec);
+}
+
+typedef void (*foo_t)(int);
+
+void
+resume_interrupt(void)
+{
+    int i;
+    regcontext_t      *REGS = saved_regcontext;
+
+    n_pending--;
+    if (n_pending == 0)
+        R_EFLAGS &= ~PSL_VIP;
+    
+    for (i = 0; i < 256; i++) {
+        if (pending[i]) {
+            ((foo_t)(pending[i]))(i);
+            pending[i] = 0;
+            break;    
+        }
+    }
+}   
+     
+     
+void 
+delay_interrupt(int intnum, void (*func)(int))
+{       
+    regcontext_t      *REGS = saved_regcontext;
+
+#if 0
+printf("DELAY [%x/%d]\n", intnum, n_pending);
+#endif
+    if (pending[intnum] == 0) {
+        pending[intnum] = (u_long)func;
+        n_pending++;
+    }
+    R_EFLAGS |= PSL_VIP;
+}