patch-2.1.121 linux/arch/i386/kernel/desc.h
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- Lines: 62
- Date:
Wed Sep 9 08:56:58 1998
- Orig file:
v2.1.120/linux/arch/i386/kernel/desc.h
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.1.120/linux/arch/i386/kernel/desc.h linux/arch/i386/kernel/desc.h
@@ -0,0 +1,61 @@
+#ifndef __ARCH_DESC_H
+#define __ARCH_DESC_H
+
+struct desc_struct {
+ unsigned long a,b;
+};
+
+extern struct desc_struct gdt_table[];
+extern struct desc_struct *idt, *gdt;
+
+struct Xgt_desc_struct {
+ unsigned short size;
+ unsigned long address __attribute__((packed));
+};
+
+#define idt_descr (*(struct Xgt_desc_struct *)((char *)&idt - 2))
+#define gdt_descr (*(struct Xgt_desc_struct *)((char *)&gdt - 2))
+
+/*
+ * Entry into gdt where to find first TSS. GDT layout:
+ * 0 - null
+ * 1 - not used
+ * 2 - kernel code segment
+ * 3 - kernel data segment
+ * 4 - user code segment
+ * 5 - user data segment
+ * 6 - not used
+ * 7 - not used
+ * 8 - APM BIOS support
+ * 9 - APM BIOS support
+ * 10 - APM BIOS support
+ * 11 - APM BIOS support
+ * 12 - TSS #0
+ * 13 - LDT #0
+ * 14 - TSS #1
+ * 15 - LDT #1
+ */
+#define FIRST_TSS_ENTRY 12
+#define FIRST_LDT_ENTRY (FIRST_TSS_ENTRY+1)
+#define _TSS(n) ((((unsigned long) n)<<4)+(FIRST_TSS_ENTRY<<3))
+#define _LDT(n) ((((unsigned long) n)<<4)+(FIRST_LDT_ENTRY<<3))
+#define load_TR(n) __asm__ __volatile__("ltr %%ax": /* no output */ :"a" (_TSS(n)))
+#define load_ldt(n) __asm__ __volatile__("lldt %%ax": /* no output */ :"a" (_LDT(n)))
+#define store_TR(n) \
+__asm__("str %%ax\n\t" \
+ "subl %2,%%eax\n\t" \
+ "shrl $4,%%eax" \
+ :"=a" (n) \
+ :"0" (0),"i" (FIRST_TSS_ENTRY<<3))
+
+extern void set_intr_gate(unsigned int irq, void * addr);
+extern void set_ldt_desc(unsigned int n, void *addr, unsigned int size);
+extern void set_tss_desc(unsigned int n, void *addr);
+
+/*
+ * This is the ldt that every process will get unless we need
+ * something other than this.
+ */
+extern struct desc_struct default_ldt;
+
+#endif
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