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/*[
lar.c
LOCAL CHAR SccsID[]="@(#)lar.c 1.5 02/09/94";
LAR CPU Functions.
------------------
]*/
#include <insignia.h>
#include <host_def.h>
#include <xt.h>
#include <c_main.h>
#include <c_addr.h>
#include <c_bsic.h>
#include <c_prot.h>
#include <c_seg.h>
#include <c_stack.h>
#include <c_xcptn.h>
#include <c_reg.h>
#include <lar.h>
/*
=====================================================================
EXTERNAL ROUTINES START HERE
=====================================================================
*/
GLOBAL VOID
LAR
IFN2(
IU32 *, pop1, /* pntr to dst operand */
IU32, op2 /* src operand */
)
{
BOOL loadable = FALSE;
IU32 descr_addr;
CPU_DESCR entry;
if ( !selector_outside_GDT_LDT((IU16)op2, &descr_addr) )
{
/* read descriptor from memory */
read_descriptor_linear(descr_addr, &entry);
switch ( descriptor_super_type(entry.AR) )
{
case INVALID:
break; /* never loaded */
case CONFORM_NOREAD_CODE:
case CONFORM_READABLE_CODE:
loadable = TRUE; /* always loadable */
break;
case INTERRUPT_GATE:
case TRAP_GATE:
case XTND_AVAILABLE_TSS:
case XTND_BUSY_TSS:
case XTND_CALL_GATE:
case XTND_INTERRUPT_GATE:
case XTND_TRAP_GATE:
case AVAILABLE_TSS:
case LDT_SEGMENT:
case BUSY_TSS:
case CALL_GATE:
case TASK_GATE:
case EXPANDUP_READONLY_DATA:
case EXPANDUP_WRITEABLE_DATA:
case EXPANDDOWN_READONLY_DATA:
case EXPANDDOWN_WRITEABLE_DATA:
case NONCONFORM_NOREAD_CODE:
case NONCONFORM_READABLE_CODE:
/* access depends on privilege, it is required that
DPL >= CPL and DPL >= RPL */
if ( GET_AR_DPL(entry.AR) >= GET_CPL() &&
GET_AR_DPL(entry.AR) >= GET_SELECTOR_RPL(op2) )
loadable = TRUE;
break;
}
}
if ( loadable )
{
/* Give em the access rights, in a suitable format */
*pop1 = (IU32)entry.AR << 8;
SET_ZF(1);
}
else
{
SET_ZF(0);
}
}
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