proc_access.h File Reference

Set of functions and flags used to manage processors registers. More...

Go to the source code of this file.

Macros
#define	CR0_PE   0x00000001u
	Protected mode Enable.
#define	CR0_MP   0x00000002u
	"Math" Present (e.g. npx), wait for it.
#define	CR0_EM   0x00000004u
	EMulate NPX, e.g. trap, don't execute code.
#define	CR0_TS   0x00000008u
	Process has done Task Switch, do NPX save.
#define	CR0_ET   0x00000010u
	32 bit (if set) vs 16 bit (387 vs 287).
#define	CR0_PG   0x80000000u
	Paging Enable.
#define	CR4_SEE   0x00008000u
	Secure Enclave Enable XXX.
#define	CR4_SMAP   0x00200000u
	Supervisor-Mode Access Protect.
#define	CR4_SMEP   0x00100000u
	Supervisor-Mode Execute Protect.
#define	CR4_OSXSAVE   0x00040000u
	OS supports XSAVE.
#define	CR4_PCIDE   0x00020000u
	PCID Enable.
#define	CR4_RDWRFSGS   0x00010000u
	RDWRFSGS Enable.
#define	CR4_SMXE   0x00004000u
	Enable SMX operation.
#define	CR4_VMXE   0x00002000u
	Enable VMX operation.
#define	CR4_OSXMM   0x00000400u
	SSE/SSE2 exception support in OS.
#define	CR4_OSFXS   0x00000200u
	SSE/SSE2 OS supports FXSave.
#define	CR4_PCE   0x00000100u
	Performance-Monitor Count Enable.
#define	CR4_PGE   0x00000080u
	Page Global Enable.
#define	CR4_MCE   0x00000040u
	Machine Check Exceptions.
#define	CR4_PAE   0x00000020u
	Physical Address Extensions.
#define	CR4_PSE   0x00000010u
	Page Size Extensions.
#define	CR4_DE   0x00000008u
	Debugging Extensions.
#define	CR4_TSD   0x00000004u
	Time Stamp Disable.
#define	CR4_PVI   0x00000002u
	Protected-mode Virtual Interrupts.
#define	CR4_VME   0x00000001u
	Virtual-8086 Mode Extensions.

Functions
static uint16_t	get_es (void)
	Reads the Extra Segment (DS). More...
static void	set_es (uint16_t es)
	Sets the Extra Segment (DS). More...
static uint16_t	get_ds (void)
	Reads the Data Segment (DS). More...
static void	set_ds (uint16_t ds)
	Sets the Data Segment (DS). More...
static uint16_t	get_fs (void)
	Reads FS. More...
static void	set_fs (uint16_t fs)
	Sets FS. More...
static uint16_t	get_gs (void)
	Reads GS. More...
static void	set_gs (uint16_t gs)
	Sets GS. More...
static uint16_t	get_ss (void)
	Reads the Stack Segment (SS). More...
static void	set_ss (uint16_t ss)
	Sets the Stack Segment (SS). More...
static uintptr_t	get_cr0 (void)
	Reads the current cr0 value. More...
static void	set_cr0 (uintptr_t cr0)
	Sets the cr0 value. More...
static uintptr_t	get_cr2 (void)
	Reads the current cr2 value. More...
static void	set_cr2 (uintptr_t cr2)
	Sets the cr2 value. More...
static uintptr_t	get_cr3 (void)
	Reads the current cr3 value. More...
static void	set_cr3 (uintptr_t cr3)
	Sets the cr3 value. More...
static uintptr_t	get_cr4 (void)
	Reads the current cr4 value. More...
static void	set_cr4 (uintptr_t cr4)
	Sets the cr4 value. More...
static uintptr_t	get_eflags (void)
	Reads entire contents of the EFLAGS register. More...
static void	clear_ts (void)
	Clears the task-switched (TS) flag in the CR0 register.
static unsigned short	get_tr (void)
	Reads the segment selector from the task register (TR). More...
static void	set_tr (unsigned short seg)
	Loads the source operand into the segment selector field of the task register. More...
static unsigned short	sldt (void)
	Reads the segment selector from the local descriptor table register (LDTR). More...
static void	lldt (unsigned short seg)
	Loads the source operand into the segment selector field of the local descriptor table register (LDTR). More...
static void	lgdt (uintptr_t *desc)
	Loads the values in the source operand into the global descriptor table register (GDTR) or the interrupt descriptor table register (IDTR). More...
static void	lidt (uintptr_t *desc)
	Loads the values in the source operand into the global descriptor table register (GDTR) or the interrupt descriptor table register (IDTR). More...
static void	sti (void)
	Set interrupt flag; external, maskable interrupts enabled at the end of the next instruction.
static void	cli (void)
	Clear interrupt flag; interrupts disabled when interrupt flag cleared.
static void	swapgs (void)
	Exchanges the current GS base register value with the value contained in MSR address C0000102H.
static void	hlt (void)
	Halts the CPU until the next external interrupt is fired.
static void	pause (void)
	Gives hint to processor that improves performance of spin-wait loops.

Detailed Description

Set of functions and flags used to manage processors registers.

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Function Documentation

get_cr0()

static uintptr_t get_cr0 ( void  )

inlinestatic

Reads the current cr0 value.

Returns

the value we read.

get_cr2()

static uintptr_t get_cr2 ( void  )

inlinestatic

Reads the current cr2 value.

Returns

the value we read.

get_cr3()

static uintptr_t get_cr3 ( void  )

inlinestatic

Reads the current cr3 value.

Returns

the value we read.

get_cr4()

static uintptr_t get_cr4 ( void  )

inlinestatic

Reads the current cr4 value.

Returns

the value we read.

get_ds()

static uint16_t get_ds ( void  )

inlinestatic

Reads the Data Segment (DS).

Returns

the value we read.

get_eflags()

static uintptr_t get_eflags ( void  )

inlinestatic

Reads entire contents of the EFLAGS register.

Returns

the content of EFLAGS.

get_es()

static uint16_t get_es ( void  )

inlinestatic

Reads the Extra Segment (DS).

Returns

the value we read.

get_fs()

static uint16_t get_fs ( void  )

inlinestatic

Reads FS.

Returns

the value we read.

get_gs()

static uint16_t get_gs ( void  )

inlinestatic

Reads GS.

Returns

the value we read.

get_ss()

static uint16_t get_ss ( void  )

inlinestatic

Reads the Stack Segment (SS).

Returns

the value we read.

get_tr()

static unsigned short get_tr ( void  )

inlinestatic

Reads the segment selector from the task register (TR).

Returns

lgdt()

static void lgdt ( uintptr_t *  desc )

inlinestatic

Loads the values in the source operand into the global descriptor table register (GDTR) or the interrupt descriptor table register (IDTR).

Parameters

desc	the value we need to load.

lidt()

static void lidt ( uintptr_t *  desc )

inlinestatic

Loads the values in the source operand into the global descriptor table register (GDTR) or the interrupt descriptor table register (IDTR).

Parameters

desc	the value we need to load.

lldt()

static void lldt ( unsigned short  seg )

inlinestatic

Loads the source operand into the segment selector field of the local descriptor table register (LDTR).

Parameters

seg	The segment selector we need to set.

set_cr0()

static void set_cr0 ( uintptr_t  cr0 )

inlinestatic

Sets the cr0 value.

Parameters

cr0	the value we want to set.

set_cr2()

static void set_cr2 ( uintptr_t  cr2 )

inlinestatic

Sets the cr2 value.

Parameters

cr2	the value we want to set.

set_cr3()

static void set_cr3 ( uintptr_t  cr3 )

inlinestatic

Sets the cr3 value.

Parameters

cr3	the value we want to set.

set_cr4()

static void set_cr4 ( uintptr_t  cr4 )

inlinestatic

Sets the cr4 value.

Parameters

cr4	the value we want to set.

set_ds()

static void set_ds ( uint16_t  ds )

inlinestatic

Sets the Data Segment (DS).

Parameters

ds	the value we set.

set_es()

static void set_es ( uint16_t  es )

inlinestatic

Sets the Extra Segment (DS).

Parameters

es	the value we set.

set_fs()

static void set_fs ( uint16_t  fs )

inlinestatic

Sets FS.

Parameters

fs	the value we set.

set_gs()

static void set_gs ( uint16_t  gs )

inlinestatic

Sets GS.

Parameters

gs	the value we set.

set_ss()

static void set_ss ( uint16_t  ss )

inlinestatic

Sets the Stack Segment (SS).

Parameters

ss	the value we set.

set_tr()

static void set_tr ( unsigned short  seg )

inlinestatic

Loads the source operand into the segment selector field of the task register.

Parameters

seg	the segment selector we want to set.

sldt()

static unsigned short sldt ( void  )

inlinestatic

Reads the segment selector from the local descriptor table register (LDTR).

Returns

the segment selector.