Moved the gdt_idt_descr struct from arch_stage2.h to stage2_priv.h.

Moved the tss_descriptor structure to descriptor.h, updated it to be a
segment_descriptor structure, and provided inlines for set_tss_descriptor(),
set_segment_descriptor(), set_segment_descriptor_base(), and
clear_segment_descriptor().
Also added defines for the different privilege levels and descriptor types.
Removed the unusused and incorrect TSS definition, introduced new
TSS_BASE_SEGMENT and TLS_BASE_SEGMENT macros.
Removed include of arch/cpu.h in arch_cpu.h.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2360 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/arch/x86/arch_cpu.h

@@ -5,8 +5,6 @@
 #ifndef _KERNEL_ARCH_x86_CPU_H
 #define _KERNEL_ARCH_x86_CPU_H
 
-/* ??? why include this as we're normally included from that file! */
-#include <arch/cpu.h>
 #include <arch/x86/thread_struct.h>
 #include <arch/x86/descriptors.h>
 
@@ -15,10 +13,6 @@
 #define _BIG_ENDIAN 0
 #define _LITTLE_ENDIAN 1
 
-typedef struct desc_struct {
-	unsigned int a,b;
-} desc_table;
-
 struct tss {
 	uint16 prev_task;
 	uint16 unused0;
@@ -38,23 +32,9 @@ struct tss {
 	uint16 io_map_base;
 };
 
-struct tss_descriptor {
+/**************************************************************************/
-	uint16 limit_00_15;
-	uint16 base_00_15;
-	uint32 base_23_16 : 8;
-	uint32 type : 4;
-	uint32 zero : 1;
-	uint32 dpl : 2;
-	uint32 present : 1;
-	uint32 limit_19_16 : 4;
-	uint32 avail : 1;
-	uint32 zero1 : 1;
-	uint32 zero2 : 1;
-	uint32 granularity : 1;
-	uint32 base_31_24 : 8;
-};
 
-typedef struct ptentry {
+typedef struct ptentry {		// page table entry
 	unsigned int present:1;
 	unsigned int rw:1;
 	unsigned int user:1;
@@ -68,7 +48,7 @@ typedef struct ptentry {
 	unsigned int addr:20;
 } ptentry;
 
-typedef struct pdentry {
+typedef struct pdentry {		// page directory entry
 	unsigned int present:1;
 	unsigned int rw:1;
 	unsigned int user:1;
@@ -175,5 +155,6 @@ __asm__ volatile ("inb %%dx,%%al\n" \
 _v; \
 })
 
-#endif
+extern segment_descriptor *gGDT;
 
+#endif	/* _KERNEL_ARCH_x86_CPU_H */

headers/private/kernel/arch/x86/arch_stage2.h

@@ -15,12 +15,6 @@
 #define IDT_LIMIT 0x800
 #define GDT_LIMIT 0x800
 
-struct gdt_idt_descr {
-	unsigned short a;
-	unsigned int *b;
-} _PACKED;
-
-
 // kernel args
 typedef struct {
 	// architecture specific
@@ -45,5 +39,4 @@ typedef struct {
 	unsigned int cpu_apic_version[MAX_BOOT_CPUS];
 } arch_kernel_args;
 
-#endif
+#endif	/* _KERNEL_ARCH_x86_STAGE2_H */
-

headers/private/kernel/arch/x86/descriptors.h

@@ -5,11 +5,122 @@
 #ifndef _KERNEL_ARCH_x86_DESCRIPTORS_H
 #define _KERNEL_ARCH_x86_DESCRIPTORS_H
 
-#define KERNEL_CODE_SEG 0x8
-#define KERNEL_DATA_SEG 0x10
-#define USER_CODE_SEG 0x1b
-#define USER_DATA_SEG 0x23
-#define TSS 0x28
 
-#endif /* _KERNEL_ARCH_x86_DESCRIPTORS_H */
+#define KERNEL_CODE_SEG	0x8
+#define KERNEL_DATA_SEG	0x10
 
+#define USER_CODE_SEG	0x1b
+#define USER_DATA_SEG	0x23
+
+
+#ifndef _ASSEMBLER
+	// this file can also be included from assembler as well
+	// (and is in arch_interrupts.S)
+
+#define TSS_BASE_SEGMENT 5
+#define TLS_BASE_SEGMENT (TSS_BASE_SEGMENT + smp_get_num_cpus())
+
+
+// defines entries in the GDT/LDT
+
+typedef struct segment_descriptor {
+	uint16 limit_00_15;				// bit	 0 - 15
+	uint16 base_00_15;				//		16 - 31
+	uint32 base_23_16 : 8;			//		 0 -  7
+	uint32 type : 4;				//		 8 - 11
+	uint32 desc_type : 1;			//		12		(0 = system, 1 = code/data)
+	uint32 privilege_level : 2;		//		13 - 14
+	uint32 present : 1;				//		15
+	uint32 limit_19_16 : 4;			//		16 - 19
+	uint32 available : 1;			//		20
+	uint32 zero : 1;				//		21
+	uint32 d_b : 1;					//		22
+	uint32 granularity : 1;			//		23
+	uint32 base_31_24 : 8;			//		24 - 31
+} segment_descriptor;
+
+enum descriptor_privilege_levels {
+	DPL_KERNEL = 0,
+	DPL_USER = 3,
+};
+
+enum descriptor_types {
+	// segment types
+	DT_CODE_EXECUTE_ONLY = 0x8,
+	DT_CODE_ACCESSED = 0x9,
+	DT_CODE_READABLE = 0xa,
+	DT_CODE_CONFORM = 0xc,
+	DT_DATA_READ_ONLY = 0x0,
+	DT_DATA_ACCESSED = 0x1,
+	DT_DATA_WRITEABLE = 0x2,
+	DT_DATA_EXPANSION_DOWN = 0x4,
+
+	DT_TSS = 9,
+
+	// descriptor types
+	DT_SYSTEM_SEGMENT = 0,
+	DT_CODE_DATA_SEGMENT = 1,
+};
+
+static inline void
+clear_segment_descriptor(struct segment_descriptor *desc)
+{
+	*(long long *)desc = 0;
+}
+
+
+static inline void
+set_segment_descriptor_base(struct segment_descriptor *desc, addr base)
+{
+	desc->base_00_15 = (addr)base & 0xffff;	// base is 32 bits long
+	desc->base_23_16 = ((addr)base >> 16) & 0xff;
+	desc->base_31_24 = ((addr)base >> 24) & 0xff;
+}
+
+
+static inline void
+set_segment_descriptor(struct segment_descriptor *desc, addr base, uint32 limit,
+	uint8 type, uint8 privilegeLevel)
+{
+	set_segment_descriptor_base(desc, base);
+
+	desc->limit_00_15 = (addr)limit & 0x0ffff;	// limit is 20 bits long
+	desc->limit_19_16 = ((addr)limit >> 16) & 0xf;
+
+	desc->type = type;
+	desc->desc_type = DT_CODE_DATA_SEGMENT;
+	desc->privilege_level = privilegeLevel;
+
+	desc->present = 1;
+	desc->granularity = 1;	// 4 GB size (in page size steps)
+	desc->available = 0;	// system available bit is currently not used
+	desc->d_b = 1;
+
+	desc->zero = 0;
+}
+
+
+static inline void
+set_tss_descriptor(struct segment_descriptor *desc, addr base, uint32 limit)
+{
+	// the TSS descriptor has a special layout different from the standard descriptor
+	set_segment_descriptor_base(desc, base);
+
+	desc->limit_00_15 = (addr)limit & 0x0ffff;
+	desc->limit_19_16 = 0;
+
+	desc->type = DT_TSS;
+	desc->desc_type = DT_SYSTEM_SEGMENT;
+	desc->privilege_level = DPL_KERNEL;
+
+	desc->present = 1;
+	desc->granularity = 1;	// 4 GB size (in page size steps)
+	desc->available = 0;	// system available bit is currently not used
+	desc->d_b = 0;
+
+	desc->zero = 0;
+}
+
+#endif	/* _ASSEMBLER */
+
+#endif	/* _KERNEL_ARCH_x86_DESCRIPTORS_H */

headers/private/kernel/arch/x86/stage2_priv.h

@@ -39,6 +39,11 @@ void cpuid(unsigned int selector, unsigned int *data);
 #define SCREEN_HEIGHT 24
 #define ADDR_MASK 0xfffff000
 
+struct gdt_idt_descr {
+	unsigned short a;
+	unsigned int *b;
+} _PACKED;
+
 // SMP stuff
 extern int smp_boot(kernel_args *ka, unsigned int kernel_entry);
 extern void smp_trampoline(void);