Encoding Instructions

When you call xed_encode() to encode instruction you must pass: More...

Typedefs
typedef struct xed_decoded_inst_s	xed_encoder_request_s
typedef xed_decoded_inst_t	xed_encoder_request_t

Functions
XED_DLL_EXPORT xed_iclass_enum_t	xed_encoder_request_get_iclass (const xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_set_iclass (xed_encoder_request_t *p, xed_iclass_enum_t iclass)

Primary Encode Functions
XED_DLL_EXPORT void	xed_encoder_request_set_effective_operand_width (xed_encoder_request_t *p, xed_uint_t width_bits)
XED_DLL_EXPORT void	xed_encoder_request_set_effective_address_size (xed_encoder_request_t *p, xed_uint_t width_bits)
XED_DLL_EXPORT void	xed_encoder_request_set_reg (xed_encoder_request_t *p, xed_operand_enum_t operand, xed_reg_enum_t reg)

Operand Order
XED_DLL_EXPORT void	xed_encoder_request_set_operand_order (xed_encoder_request_t *p, xed_uint_t operand_index, xed_operand_enum_t name)
XED_DLL_EXPORT xed_operand_enum_t	xed_encoder_request_get_operand_order (xed_encoder_request_t *p, xed_uint_t operand_index)
static XED_INLINE xed_uint_t	xed_encoder_request_operand_order_entries (xed_encoder_request_t *p)

branches and far pointers
XED_DLL_EXPORT void	xed_encoder_request_set_relbr (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_set_absbr (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_set_branch_displacement (xed_encoder_request_t *p, xed_int64_t brdisp, xed_uint_t nbytes)
XED_DLL_EXPORT void	xed_encoder_request_set_ptr (xed_encoder_request_t *p)

Immediates
XED_DLL_EXPORT void	xed_encoder_request_set_uimm0 (xed_encoder_request_t *p, xed_uint64_t uimm, xed_uint_t nbytes)
XED_DLL_EXPORT void	xed_encoder_request_set_uimm0_bits (xed_encoder_request_t *p, xed_uint64_t uimm, xed_uint_t nbits)
XED_DLL_EXPORT void	xed_encoder_request_set_uimm1 (xed_encoder_request_t *p, xed_uint8_t uimm)
XED_DLL_EXPORT void	xed_encoder_request_set_simm (xed_encoder_request_t *p, xed_int32_t simm, xed_uint_t nbytes)

Memory
XED_DLL_EXPORT void	xed_encoder_request_set_memory_displacement (xed_encoder_request_t *p, xed_int64_t memdisp, xed_uint_t nbytes)
XED_DLL_EXPORT void	xed_encoder_request_set_agen (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_set_mem0 (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_set_mem1 (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_set_memory_operand_length (xed_encoder_request_t *p, xed_uint_t nbytes)
XED_DLL_EXPORT void	xed_encoder_request_set_seg0 (xed_encoder_request_t *p, xed_reg_enum_t seg_reg)
XED_DLL_EXPORT void	xed_encoder_request_set_seg1 (xed_encoder_request_t *p, xed_reg_enum_t seg_reg)
XED_DLL_EXPORT void	xed_encoder_request_set_base0 (xed_encoder_request_t *p, xed_reg_enum_t base_reg)
XED_DLL_EXPORT void	xed_encoder_request_set_base1 (xed_encoder_request_t *p, xed_reg_enum_t base_reg)
XED_DLL_EXPORT void	xed_encoder_request_set_index (xed_encoder_request_t *p, xed_reg_enum_t index_reg)
XED_DLL_EXPORT void	xed_encoder_request_set_scale (xed_encoder_request_t *p, xed_uint_t scale)
static const XED_INLINE xed_operand_values_t *	xed_encoder_request_operands_const (const xed_encoder_request_t *p)
static XED_INLINE xed_operand_values_t *	xed_encoder_request_operands (xed_encoder_request_t *p)

Initialization
XED_DLL_EXPORT void	xed_encoder_request_zero_operand_order (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_zero_set_mode (xed_encoder_request_t *p, const xed_state_t *dstate)
XED_DLL_EXPORT void	xed_encoder_request_zero (xed_encoder_request_t *p)
XED_DLL_EXPORT void	xed_encoder_request_init_from_decode (struct xed_decoded_inst_s *d)

String Printing
XED_DLL_EXPORT void	xed_encode_request_print (const xed_encoder_request_t *p, char *buf, xed_uint_t buflen)

Encoding
XED_DLL_EXPORT xed_error_enum_t	xed_encode (xed_encoder_request_t *r, xed_uint8_t *array, const unsigned int ilen, unsigned int *olen)
	This is the main interface to the encoder. More...
XED_DLL_EXPORT xed_error_enum_t	xed_encode_nop (xed_uint8_t *array, const unsigned int ilen)
	This function will attempt to encode a NOP of exactly ilen bytes. More...

Detailed Description

When you call xed_encode() to encode instruction you must pass:

• an encode structure that includes a machine state ( xed_state_t )
• a pointer to the instruction text
• a length of the text array

The class xed_encoder_request_t includes a xed_operand_values_t and that is where most of the information about the operands, resources etc. are stored.

To get nondefault width operands, during encoding, you have to
call #xed_encoder_request_set_effective_operand_width() .


To set nondefault addressing widths, you must call
#xed_encoder_request_set_effective_address_size().



To encode instructions you must set the following 

in the xed_encoder_request_t.

1. the machine mode (machine width, and stack addressing width)
2. the effective operand width
3. the iclass
4. for some instructions you need to specify prefixes (like REP, REPNE or LOCK).
5. the operands:

   1. operand kind (XED_OPERAND_{AGEN,MEM0,MEM1,IMM0,IMM1,RELBR,ABSBR,PTR,REG0...REG15}

   2. operand order
      xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_*); where the operand_index is a sequential index starting at zero.

   3. operand details
      1. FOR MEMOPS: base,segment,index,scale,displacement for memops,
      2. FOR REGISTERS: register name
      3. FOR IMMEDIATES: immediate values

See An example of using the encoder for an example of using the encoder.

Typedef Documentation

xed_encoder_request_s

typedef struct xed_decoded_inst_s xed_encoder_request_s

xed_encoder_request_t

typedef xed_decoded_inst_t xed_encoder_request_t

Function Documentation

xed_encode()

XED_DLL_EXPORT xed_error_enum_t xed_encode	(	xed_encoder_request_t *	r,
		xed_uint8_t *	array,
		const unsigned int	ilen,
		unsigned int *	olen
	)

This is the main interface to the encoder.

The array should be at most 15 bytes long. The ilen parameter should indicate this length. If the array is too short, the encoder may fail to encode the request. Failure is indicated by a return value of type xed_error_enum_t that is not equal to XED_ERROR_NONE. Otherwise, XED_ERROR_NONE is returned and the length of the encoded instruction is returned in olen.

Parameters

r	encoder request description (xed_encoder_request_t), includes mode info
array	the encoded instruction bytes are stored here
ilen	the input length of array.
olen	the actual length of array used for encoding

Returns

success/failure as a xed_error_enum_t

xed_encode_nop()

XED_DLL_EXPORT xed_error_enum_t xed_encode_nop	(	xed_uint8_t *	array,
		const unsigned int	ilen
	)

This function will attempt to encode a NOP of exactly ilen bytes.

If such a NOP is not encodeable, then false will be returned.

Parameters

array	the encoded instruction bytes are stored here
ilen	the input length array.

Returns

success/failure as a xed_error_enum_t

xed_encode_request_print()

XED_DLL_EXPORT void xed_encode_request_print	(	const xed_encoder_request_t *	p,
		char *	buf,
		xed_uint_t	buflen
	)

xed_encoder_request_get_iclass()

XED_DLL_EXPORT xed_iclass_enum_t xed_encoder_request_get_iclass

(

const xed_encoder_request_t *

p

)

xed_encoder_request_get_operand_order()

XED_DLL_EXPORT xed_operand_enum_t xed_encoder_request_get_operand_order	(	xed_encoder_request_t *	p,
		xed_uint_t	operand_index
	)

Retrieve the name of the n'th operand in the operand order.

Parameters

[in]	p	xed_encoder_request_t
[in]	operand_index	xed_uint_t representing n'th operand position

Returns

The xed_operand_enum_t operand name.

xed_encoder_request_init_from_decode()

XED_DLL_EXPORT void xed_encoder_request_init_from_decode

(

struct xed_decoded_inst_s *

d

)

Converts an decoder request to a valid encoder request.

xed_encoder_request_operand_order_entries()

static XED_INLINE xed_uint_t xed_encoder_request_operand_order_entries ( xed_encoder_request_t *  p )

static

Retrieve the number of entries in the encoder operand order array

Returns

The number of entries in the encoder operand order array

xed_encoder_request_operands()

static XED_INLINE xed_operand_values_t* xed_encoder_request_operands ( xed_encoder_request_t *  p )

static

xed_encoder_request_operands_const()

static const XED_INLINE xed_operand_values_t* xed_encoder_request_operands_const ( const xed_encoder_request_t *  p )

static

xed_encoder_request_set_absbr()

XED_DLL_EXPORT void xed_encoder_request_set_absbr

(

xed_encoder_request_t *

p

)

xed_encoder_request_set_agen()

XED_DLL_EXPORT void xed_encoder_request_set_agen

(

xed_encoder_request_t *

p

)

xed_encoder_request_set_base0()

XED_DLL_EXPORT void xed_encoder_request_set_base0	(	xed_encoder_request_t *	p,
		xed_reg_enum_t	base_reg
	)

xed_encoder_request_set_base1()

XED_DLL_EXPORT void xed_encoder_request_set_base1	(	xed_encoder_request_t *	p,
		xed_reg_enum_t	base_reg
	)

xed_encoder_request_set_branch_displacement()

XED_DLL_EXPORT void xed_encoder_request_set_branch_displacement	(	xed_encoder_request_t *	p,
		xed_int64_t	brdisp,
		xed_uint_t	nbytes
	)

xed_encoder_request_set_effective_address_size()

XED_DLL_EXPORT void xed_encoder_request_set_effective_address_size	(	xed_encoder_request_t *	p,
		xed_uint_t	width_bits
	)

xed_encoder_request_set_effective_operand_width()

XED_DLL_EXPORT void xed_encoder_request_set_effective_operand_width	(	xed_encoder_request_t *	p,
		xed_uint_t	width_bits
	)

xed_encoder_request_set_iclass()

XED_DLL_EXPORT void xed_encoder_request_set_iclass	(	xed_encoder_request_t *	p,
		xed_iclass_enum_t	iclass
	)

xed_encoder_request_set_index()

XED_DLL_EXPORT void xed_encoder_request_set_index	(	xed_encoder_request_t *	p,
		xed_reg_enum_t	index_reg
	)

xed_encoder_request_set_mem0()

XED_DLL_EXPORT void xed_encoder_request_set_mem0

(

xed_encoder_request_t *

p

)

xed_encoder_request_set_mem1()

XED_DLL_EXPORT void xed_encoder_request_set_mem1

(

xed_encoder_request_t *

p

)

xed_encoder_request_set_memory_displacement()

XED_DLL_EXPORT void xed_encoder_request_set_memory_displacement	(	xed_encoder_request_t *	p,
		xed_int64_t	memdisp,
		xed_uint_t	nbytes
	)

xed_encoder_request_set_memory_operand_length()

XED_DLL_EXPORT void xed_encoder_request_set_memory_operand_length	(	xed_encoder_request_t *	p,
		xed_uint_t	nbytes
	)

xed_encoder_request_set_operand_order()

XED_DLL_EXPORT void xed_encoder_request_set_operand_order	(	xed_encoder_request_t *	p,
		xed_uint_t	operand_index,
		xed_operand_enum_t	name
	)

Specify the name as the n'th operand in the operand order.

The complication of this function is that the register operand names are specific to the position of the operand (REG0, REG1, REG2...). One can use this function for registers or one can use the xed_encoder_request_set_operand_name_reg() which takes integers instead of operand names.

Parameters

[in]	p	xed_encoder_request_t
[in]	operand_index	xed_uint_t representing n'th operand position
[in]	name	xed_operand_enum_t operand name.

xed_encoder_request_set_ptr()

XED_DLL_EXPORT void xed_encoder_request_set_ptr

(

xed_encoder_request_t *

p

)

xed_encoder_request_set_reg()

XED_DLL_EXPORT void xed_encoder_request_set_reg	(	xed_encoder_request_t *	p,
		xed_operand_enum_t	operand,
		xed_reg_enum_t	reg
	)

Set the operands array element indexed by operand to the actual register name reg.

Parameters

[in]	p	xed_encoder_request_t
[in]	operand	indicates which register operand storage field to use
[in]	reg	the actual register represented (EAX, etc.) to store.

xed_encoder_request_set_relbr()

XED_DLL_EXPORT void xed_encoder_request_set_relbr

(

xed_encoder_request_t *

p

)

xed_encoder_request_set_scale()

XED_DLL_EXPORT void xed_encoder_request_set_scale	(	xed_encoder_request_t *	p,
		xed_uint_t	scale
	)

xed_encoder_request_set_seg0()

XED_DLL_EXPORT void xed_encoder_request_set_seg0	(	xed_encoder_request_t *	p,
		xed_reg_enum_t	seg_reg
	)

xed_encoder_request_set_seg1()

XED_DLL_EXPORT void xed_encoder_request_set_seg1	(	xed_encoder_request_t *	p,
		xed_reg_enum_t	seg_reg
	)

xed_encoder_request_set_simm()

XED_DLL_EXPORT void xed_encoder_request_set_simm	(	xed_encoder_request_t *	p,
		xed_int32_t	simm,
		xed_uint_t	nbytes
	)

same storage as uimm0

xed_encoder_request_set_uimm0()

XED_DLL_EXPORT void xed_encoder_request_set_uimm0	(	xed_encoder_request_t *	p,
		xed_uint64_t	uimm,
		xed_uint_t	nbytes
	)

Set the uimm0 using a BYTE width.

xed_encoder_request_set_uimm0_bits()

XED_DLL_EXPORT void xed_encoder_request_set_uimm0_bits	(	xed_encoder_request_t *	p,
		xed_uint64_t	uimm,
		xed_uint_t	nbits
	)

Set the uimm0 using a BIT width.

xed_encoder_request_set_uimm1()

XED_DLL_EXPORT void xed_encoder_request_set_uimm1	(	xed_encoder_request_t *	p,
		xed_uint8_t	uimm
	)

xed_encoder_request_zero()

XED_DLL_EXPORT void xed_encoder_request_zero

(

xed_encoder_request_t *

p

)

xed_encoder_request_zero_operand_order()

XED_DLL_EXPORT void xed_encoder_request_zero_operand_order

(

xed_encoder_request_t *

p

)

clear the operand order array

Parameters

[in]

p

xed_encoder_request_t

xed_encoder_request_zero_set_mode()

XED_DLL_EXPORT void xed_encoder_request_zero_set_mode	(	xed_encoder_request_t *	p,
		const xed_state_t *	dstate
	)