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;----------------------------------------------------------------------------; MRCI.INC - Microsoft Real-Time Compression Interface definitions;; Microsoft Confidential; Copyright (C) Microsoft Corporation 1992; All Rights Reserved.;; History:; 18-Jul-92 bens Initial version.; 25-Jul-92 billkru Adapted for use by MS-Flash & ROMDOS environment.;----------------------------------------------------------------------------intMRCIROM equ 1Ah ; ROM MRCI interrupt numbermrciDETECTROM equ 0B001h ; ROM intMRCI AX for detecting MRCI serverintMRCI equ 2Fh ; MRCI interrupt numbermrciDETECT equ 4a12h ; intMRCI AX for detecting MRCI server
mrciBackPatch equ 4a13h
;----------------------------------------------------------------------------; sigOLD_CX, sigOLD_DX, sigNEW_CX, sigNEW_DX - MRCI Server detection;; These values are used to verify that the response from issuing; intMRCI is coming from an MRCI server, and not some other piece; of code.;; The *old* values are passed on the mrciQUERY call, and the server; must change CX/DX to the *new* values, so that the caller can; trust that the MRCI server was responding, and not some other; interrupt hooker.;; The Server uses this code sequence to transform CX/DX:;; ;------------- entry: cx='ab' dx='cd'; xchg ch,cl ; cx='ba' dx='cd'; xchg dh,dl ; cx='ba' dx='dc'; xchg dx,cx ; cx='dc' dx='ba';----------------------------------------------------------------------------sigOLD_CX equ 'MR'sigOLD_DX equ 'CI'
sigNEW_CX equ 'IC'sigNEW_DX equ 'RM'
;----------------------------------------------------------------------------; mcXXXX - flag values passed to MRCI operations;; MRCCompress and MRCDecompress take a flag to indicate whether the; client is a *system* component (and hence may call with InDOS; set), or an *application*.;; If a system client calls MRCCompress/MRCDecompress with mcSYSTEM,; then it is the clients responsibility to ensure that one of the; following is true:; 1) InDOS is set; 2) The call is made at interrupt time.;; FAILING TO FOLLOW THE ABOVE RULE WILL LIKELY RESULT IN A SYSTEM; HANG AND LOSS OF USER DATA.;----------------------------------------------------------------------------mcAPPLICATION equ 0 ; Client is an applicationmcSYSTEM equ 1 ; Client is a file system driver
;----------------------------------------------------------------------------; MRCI Server Busy flag values;----------------------------------------------------------------------------MRCI_SERVER_IDLE equ 0
;----------------------------------------------------------------------------; MRCINFO - MRC Information data structure;; A pointer to an MRCINFO structure is returned from MRCQuery, and sent; on MRCNotifyLoad. This structure contains information on the MRCI; server and its capabilities.;----------------------------------------------------------------------------MRCINFO strucmi_lVendor dd ? ; A 4-byte vendor ID. ; Microsoft's vendor ID is "MSFT".
mi_wVendorVersion dw ? ; Version number of the MRC server. ; High byte is major number, low byte is minor. ; EXAMPLES: v3.20 = 0314h, v10.01 = 0A01h
mi_wMRCIVersion dw ? ; Version number of the MRCI supported by ; this server.
mi_pfnOperate dd ? ; Far pointer of the server compression entry ; point.
mi_flCapability dw ? ; Bit field of server capabilities ; See micapXXX for bit definitions
mi_flHWAssist dw ? ; Bit field of hardware assisted ; server capabilities. One-to-one ; correspondance with mi_flCapability ; bits. A bit set in this field ; indicates the corresponding ; capability is hardware assisted.
mi_cbMax dw ? ; Maximum number of bytes that the compression ; services provider can compress or decompress. ; Requests to compress or decompress buffers in ; excess of this length will fail. ; All MRCI servers must support at least ; 8192 byte (8Kb) blocks.MRCINFO ends
;----------------------------------------------------------------------------; micapXXXXX - bit flags for MRCINFO.mi_flCapabilities;; These define both the capabilities of the Server, and also double; as *operation* codes passed to the mi_pfnOperate entry point in; the server.; 111111; 5432109876543210;----------------------------------------------------------------------------micapNONE equ 0000000000000000b ; No capabilitiesmicapSTANDARD equ 0000000000000001b ; Standard compressmicapDECOMPRESS equ 0000000000000010b ; Standard compressmicapUPDATE equ 0000000000000100b ; Update compressmicapSUPER equ 0000000000001000b ; SuperCompress(tm)micapSUPERUPDATE equ 0000000000010000b ; Update SuperCompress(tm)micapINCDECOMP equ 0000000000100000b ; Incremental Decompress ; Remaining bits (6..14) are RESERVED and must be 0micapREADONLY equ 1000000000000000b ; MRCINFO structure is read-onlymicapDEINSTALL equ 1111111111111111b ; Server deinstall service
;----------------------------------------------------------------------------; MRCREQUEST - MRC compress/decompress Request packet;; This structure is used to pass parameters to the server for; compress/decompress operations.;; General Notes; -------------; 1) <mr_pbSrc,mr_cbSrc> and <mr_pbDst,mr_cbDst> MUST NOT OVERLAP!;; 2) The safest practice is for mr_cbSrc and mr_cbDst to be identical; (except for decompress where mr_cbSrc is ignored and mr_cbDst is; the count of bytes to uncompress).;; Details on Structure Members; ----------------------------; mr_pbSrc; This points to the *source* buffer.;; On a *compress* operation, the contents of this buffer are; *uncompressed* data.;; On an *update* operation, the contents of this buffer starting; at offset mr_offUpdate is valid, uncompressed data. The contents; from the start of the buffer to the byte just prior to; mr_OffUpdate are ignored.;; On a *decompress* operation, the contents of this buffer are; *compressed* data.;; mr_cbSrc; This is the size of the *source* buffer.;; This is the amount of data to be compressed or decompressed.; NOTE: For a decompress operation, this value may be ignored; by many implentations, since the MRC Format encoding has; a special code to indicate the end of the compressed data.;; mr_offUpdate; NOTE: This is used for Update(Super)Compress only.;; On INPUT, this is the offset (same segment as mr_pbSrc) in the; *source* buffer where the changed uncompressed data starts.;; On OUTPUT, this is the offset (same segment as mr_pbDst) in the; *destination* buffer where the changed compressed data starts.;; mr_pbDst; This points to the *destination* buffer.;; On a *compress* operation, this buffer receives the *compressed*; result of the operation.;; On an *update* operation, the contents of this buffer MUST be; the compressed representation of the uncompressed data in the; *source* buffer. After the operation is completed, this buffer; receives the *compressed* result of the operation.;; On a *decompress* operation, this buffer receives the; *uncompressed* result of the operation.;; mr_cbDst; On a *compress* operation and on INPUT, this is the size of; the *destination* buffer. If, during the operation, the; Server would overflow this buffer length, then the operation; fails and the server returns the error MRCI_ERROR_BUFFER_OVERFLOW.;; On a *decompress* operation and on INPUT, this is what the; *decompressed* size should be. If, during the operation, the; Server would overflow this length, then the operation fails; and the server returns the error MRCI_ERROR_BUFFER_OVERFLOW.;; On OUTPUT, the Server updates this field with the actual size; of the resulting compressed/uncompressed data.;; mr_cbChunk; This is information that the Server compress routines can use to; "early out" of the compression as early as possible.;; Valid values are 1 (client is interested in savings as small as; 1 byte) to 32767. DblSpace passes 512, and MS-Flash passes 1.;; This field is most easily explained by giving an example:;; Example:; DblSpace does space allocation in chunks of 512 bytes (the; common sector size on a disk).;; The compression server can use this information for two; optimizations:;; 1) If the Server cannot compress the uncompressed data; enough to save at least 512 bytes, then the data is; *incompressible* as far as DblSpace is concerned, even; if it could be compressed to save fewer than 512 bytes.;; 2) While compressing, if the Server gets to a point where; the remaining uncompressed data is of such a length that; it can be encoded simply (without table lookups, etc.); and not cross a 512 byte boundary, then the Server can; do the simple encoding.;; It is likely that these optimizations will be hard to perform; quickly in software, but it is possible that hardware can do; these optimizations without any performance loss.;----------------------------------------------------------------------------MRCREQUEST strucmr_pbSrc dd ? ; Pointer to source buffermr_cbSrc dw ? ; Size of source buffer, in bytesmr_offUpdate dw ? ; For UpdateCompress only: offset of (source) destination ; buffer where changed (un)compressed data starts.mr_pbDst dd ? ; Pointer to destination buffermr_cbDst dw ? ; Size of destination buffer, in bytesmr_cbChunk dw ? ; Client compressed data storage chunk size (see above!)mr_dwIncDecomp dd ? ; Incremental Decompression stateMRCREQUEST ends
;----------------------------------------------------------------------------; MRCI_ERROR_XXX definitions;; Error codes returned from a request;----------------------------------------------------------------------------MRCI_ERROR_NONE equ 0 ; No errorMRCI_ERROR_NOT_SUPPORTED equ 1 ; Unsupported operation requestedMRCI_ERROR_BUSY equ 2 ; Server is busyMRCI_ERROR_BUFFER_OVERFLOW equ 3 ; Destination buffer too smallMRCI_ERROR_NOT_COMPRESSIBLE equ 4 ; Data could not be compressedMRCI_ERROR_BAD_MRC_FORMAT equ 5 ; Compressed data format is bad
;---------------------------------------------------------------------------; DblSpace MRCI Server constants;---------------------------------------------------------------------------
MRCIVERSION equ 0100h ; MRCI version supported by this serverMYVERSION equ 0100h ; Version of this server/driver
MYVENDOR equ 5446534Dh ; "MSFT" (reversed for byte ordering)MYVENDORhi equ 5446h ; High word of MYVENDORMYVENDORlo equ 534Dh ; Low word of MYVENDOR
; Max buffer size set to 32k to avoid problems with compression code and; buffer offsets near 0E000h. See comments in rcomp.asm for details.
MYCBMAX equ (32*1024) ; Maximum compression buffer size
; This server's capabilities.
micapMINE = micapSTANDARD or micapDECOMPRESS or micapINCDECOMP
MYHWASSIST equ 0 ;we have no hardware assist
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