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authorThomas Bushnell <thomas@gnu.org>1997-02-25 21:28:37 +0000
committerThomas Bushnell <thomas@gnu.org>1997-02-25 21:28:37 +0000
commitf07a4c844da9f0ecae5bbee1ab94be56505f26f7 (patch)
tree12b07c7e578fc1a5f53dbfde2632408491ff2a70 /i386/pc/real_tss.c
Initial source
Diffstat (limited to 'i386/pc/real_tss.c')
-rw-r--r--i386/pc/real_tss.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/i386/pc/real_tss.c b/i386/pc/real_tss.c
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+++ b/i386/pc/real_tss.c
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+/*
+ * Copyright (c) 1995-1994 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ * Author: Bryan Ford, University of Utah CSL
+ */
+
+#include <mach/machine/tss.h>
+#include <mach/machine/proc_reg.h>
+
+#include "cpu.h"
+#include "real_tss.h"
+#include "vm_param.h"
+#include "config.h"
+
+#ifdef ENABLE_REAL_TSS
+
+static void real_tss_init()
+{
+ /* Only initialize once. */
+ if (!real_tss.ss0)
+ {
+ /* Initialize the real-mode TSS. */
+ real_tss.ss0 = KERNEL_DS;
+ real_tss.esp0 = get_esp();
+ real_tss.io_bit_map_offset = sizeof(real_tss);
+
+ /* Set the last byte in the I/O bitmap to all 1's. */
+ ((unsigned char*)&real_tss)[REAL_TSS_SIZE] = 0xff;
+ }
+}
+
+void
+cpu_gdt_init_REAL_TSS(struct cpu *cpu)
+{
+ real_tss_init();
+
+ fill_gdt_descriptor(cpu, REAL_TSS,
+ kvtolin(&real_tss), REAL_TSS_SIZE-1,
+ ACC_PL_K|ACC_TSS, 0);
+}
+
+#endif ENABLE_REAL_TSS