Initial source

1 files changed, 80 insertions, 0 deletions

diff --git a/i386/util/gdt.c b/i386/util/gdt.c
new file mode 100644
index 0000000..7bfa6aa
--- /dev/null
+++ b/i386/util/gdt.c
@@ -0,0 +1,80 @@
+/* 
+ * Mach Operating System
+ * Copyright (c) 1991,1990 Carnegie Mellon University
+ * Copyright (c) 1991 IBM Corporation 
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation,
+ * and that the name IBM not be used in advertising or publicity 
+ * pertaining to distribution of the software without specific, written
+ * prior permission.
+ * 
+ * CARNEGIE MELLON AND IBM ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON AND IBM DISCLAIM ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+
+#include "cpu.h"
+#include "vm_param.h"
+
+
+/* Initialize the 32-bit kernel code and data segment descriptors
+   to point to the base of the kernel linear space region.  */
+gdt_desc_initializer(KERNEL_CS,
+		     kvtolin(0), 0xffffffff,
+		     ACC_PL_K|ACC_CODE_R, SZ_32);
+gdt_desc_initializer(KERNEL_DS,
+		     kvtolin(0), 0xffffffff,
+		     ACC_PL_K|ACC_DATA_W, SZ_32);
+
+/* Initialize the 16-bit real-mode code and data segment descriptors. */
+gdt_desc_initializer(KERNEL_16_CS,
+		     kvtolin(0), 0xffff,
+		     ACC_PL_K|ACC_CODE_R, SZ_16);
+gdt_desc_initializer(KERNEL_16_DS,
+		     kvtolin(0), 0xffff,
+		     ACC_PL_K|ACC_DATA_W, SZ_16);
+
+/* Initialize the linear-space data segment descriptor. */
+gdt_desc_initializer(LINEAR_CS,
+		     0, 0xffffffff,
+		     ACC_PL_K|ACC_CODE_R, SZ_32);
+gdt_desc_initializer(LINEAR_DS,
+		     0, 0xffffffff,
+		     ACC_PL_K|ACC_DATA_W, SZ_32);
+
+/* Initialize the master LDT and TSS descriptors.  */
+#ifdef ENABLE_KERNEL_LDT
+gdt_desc_initializer(KERNEL_LDT,
+		     kvtolin(&cpu->tables.ldt), sizeof(cpu->tables.ldt)-1,
+		     ACC_PL_K|ACC_LDT, 0);
+#endif
+#ifdef ENABLE_KERNEL_TSS
+gdt_desc_initializer(KERNEL_TSS,
+		     kvtolin(&cpu->tables.tss), sizeof(cpu->tables.tss)-1,
+		     ACC_PL_K|ACC_TSS, 0);
+#endif
+
+
+void cpu_gdt_init(struct cpu *cpu)
+{
+	/* Initialize all the selectors of the GDT.  */
+#define gdt_sel(name) cpu_gdt_init_##name(cpu);
+#include "gdt_sels.h"
+#undef gdt_sel
+}
+