kernel/x86_64: adjust descriptors tables for compatibility mode.

* also adjust BOOT_GDT_SEGMENT_COUNT for x86, the definition is used by the
boot loader.
* add some 32-bit definitions.
* add a UserTLSDescriptor class, this will be used by 32-bit threads.

Change-Id: I5b1d978969a1ce97091a16c9ec2ad7c0ca831656

headers/private/kernel/arch/x86/32/descriptors.h

@@ -16,7 +16,7 @@
 #define USER_CODE_SEGMENT			3
 #define USER_DATA_SEGMENT			4
 
-#define BOOT_GDT_SEGMENT_COUNT		(USER_DATA_SEGMENT + 1)
+#define BOOT_GDT_SEGMENT_COUNT		(USER_DATA_SEGMENT + 2) // match x86_64
 
 #define APM_CODE32_SEGMENT			5
 #define APM_CODE16_SEGMENT			6

headers/private/kernel/arch/x86/64/descriptors.h

@@ -10,16 +10,18 @@
 // Note that the ordering of these is important to SYSCALL/SYSRET.
 #define KERNEL_CODE_SEGMENT		1
 #define KERNEL_DATA_SEGMENT		2
-#define USER_DATA_SEGMENT		3
-#define USER_CODE_SEGMENT		4
+#define USER32_CODE_SEGMENT		3
+#define USER_DATA_SEGMENT		4
+#define USER_CODE_SEGMENT		5
 
 #define BOOT_GDT_SEGMENT_COUNT	(USER_CODE_SEGMENT + 1)
 
 #define KERNEL_CODE_SELECTOR	((KERNEL_CODE_SEGMENT << 3) | DPL_KERNEL)
 #define KERNEL_DATA_SELECTOR	((KERNEL_DATA_SEGMENT << 3) | DPL_KERNEL)
 
-#define USER_CODE_SELECTOR	((USER_CODE_SEGMENT << 3) | DPL_USER)
-#define USER_DATA_SELECTOR	((USER_DATA_SEGMENT << 3) | DPL_USER)
+#define USER32_CODE_SELECTOR	((USER32_CODE_SEGMENT << 3) | DPL_USER)
+#define USER_CODE_SELECTOR		((USER_CODE_SEGMENT << 3) | DPL_USER)
+#define USER_DATA_SELECTOR		((USER_DATA_SEGMENT << 3) | DPL_USER)
 
 
 #ifndef _ASSEMBLER
@@ -90,6 +92,9 @@ set_segment_descriptor(segment_descriptor* desc, uint8 type, uint8 dpl)
 }
 
 
+unsigned x86_64_set_user_tls_segment_base(int cpu, addr_t base);
+
+
 #endif	/* _ASSEMBLER */
 
 #endif	/* _KERNEL_ARCH_X86_64_DESCRIPTORS_H */

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

@@ -54,6 +54,18 @@
 #define USER_STACK_REGION		0x7f0000000000
 #define USER_STACK_REGION_SIZE	((USER_TOP - USER_STACK_REGION) + 1)
 
+#ifdef _COMPAT_MODE
+
+#define USER32_SIZE				0x100000000
+#define USER32_TOP				(USER_BASE + (USER32_SIZE - 1))
+
+#define KERNEL_USER32_DATA_BASE	0x60000000
+
+#define USER32_STACK_REGION		0x70000000
+#define USER32_STACK_REGION_SIZE	((USER32_TOP - USER32_STACK_REGION) + 1)
+
+#endif // _COMPAT_MODE
+
 
 #else	// __x86_64__
 

headers/private/kernel/thread_types.h

@@ -837,6 +837,9 @@ using BKernel::ProcessGroupList;
 #define	THREAD_FLAGS_TRAP_FOR_CORE_DUMP		0x1000
 	// core dump in progress; the thread shall not exit the kernel to userland,
 	// but shall invoke core_dump_trap_thread() instead.
-
+#ifdef _COMPAT_MODE
+#define	THREAD_FLAGS_COMPAT_MODE			0x2000
+	// the thread runs a compatibility mode (for instance IA32 on x86_64).
+#endif
 
 #endif	/* _KERNEL_THREAD_TYPES_H */

headers/private/system/tls.h

@@ -10,6 +10,7 @@
 
 
 #define TLS_SIZE (TLS_MAX_KEYS * sizeof(void *))
+#define TLS_COMPAT_SIZE (TLS_MAX_KEYS * sizeof(uint32))
 
 enum {
 	TLS_BASE_ADDRESS_SLOT = 0,