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Diffstat (limited to 'private/ntos/boot/bootcode/hpfs/i386/fnode.inc')
| -rw-r--r-- | private/ntos/boot/bootcode/hpfs/i386/fnode.inc | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/private/ntos/boot/bootcode/hpfs/i386/fnode.inc b/private/ntos/boot/bootcode/hpfs/i386/fnode.inc new file mode 100644 index 000000000..af0207520 --- /dev/null +++ b/private/ntos/boot/bootcode/hpfs/i386/fnode.inc @@ -0,0 +1,214 @@ +;** FNODE.H - Fnode definitions +; +; FILESYS +; Gregory A. Jones +; Copyright 1988 Microsoft Corporation +; +; Modification history: +; P.A. Williams 06/01/89 Added fields FN_ACLBASE and FN_NEACNT +; to fnode. +; P.A. Williams 08/01/89 Added typedef FNODE and PFNODE, ALBLK, PALBLK, +; ALLEAF, PALLEAF, ALSEC, and PALSEC. +; + + +;* File Allocation Tracking +; +; File space is allocated as a list of extents, each extent as +; large as we can make it. This list is kept in a B+TREE format. +; Each B+TREE block consists of a single sector containing an +; ALSEC record, except for the top most block. The topmost block +; consists of just an ALBLK structure, is usually much smaller than +; 512 bytes, and is typically included in another structure. +; +; The leaf block(s) in the tree contain triples which indicate +; the logical to physical mapping for this file. Typically this +; extent list is small enough that it is wholy contained in the +; fnode ALBLK stucture. If more than ALCNT extents are required +; then the tree is split into two levels. Note that when the +; topmost B+TREE block is 'split' no actual split is necessary, +; since the new child block is much bigger than the parent block +; and can contain all of the old records plus the new one. Thus, +; we can have B+TREEs where the root block contains only one +; downpointer. +; +; The following rules apply: +; +; 1) if the file is not empty, there is at least one sector allocated +; to logical offset 0. This simplifys some critical loops. +; +; 2) The last entry in the last node block contains a AN_LOF value of +; FFFFFFFF. This allows us to extend that last leaf block +; without having to update the node block. +; +; 3) For the node records, the AN_SEC points to a node or leaf +; sector which describes extents which occur before that +; record's AN_LOF value. +; + +;* Allocation block structure +; +; Each allocation block consists of one of these. This may be +; a small block imbedded in an FNODE or OFT structure, or it +; may occupy a whole sector and be embedded in an ALSEC structure. +; + +ALBLK struc + AB_FLAG db ? ; flags + AB_FLAG2 db 3 dup (?) ; unused - sometimes copied with AB_FLAG + AB_FCNT db ? ; free count - slots for ALLEAF or ALNODE + AB_OCNT db ? ; occupied count - # of ALLEAF or ALNODEs + AB_FREP dw ? ; offset to last item+1 + ; ALLEAF or ALNODE records go here +ALBLK ends + +ABF_NODE equ 80h ; if not a leaf node +ABF_BIN equ 40h ; suggest using binary search to find +ABF_FNP equ 20h ; parent is an FNODE +ABF_NFG equ 01h ; not a flag, high order bit of AB_FREP + +; Allocation Node Structure +; +; These follow an ALBLK header for a node block + +ALNODE struc + AN_LOF dd ? ; logical offset (sectors + AN_SEC dd ? ; sector for guys < this +ALNODE ends + + +; Allocation Leaf Structure +; +; These follow an ALBLK header in a leaf block + +ALLEAF struc + AL_LOF dd ? ; logical sector offset (sectors) + AL_LEN dd ? ; length of extent (sectors) + AL_POF dd ? ; physical sector offset (sectors) +ALLEAF ends + + +;* Allocation Sector Structure +; +; Root ALBLK structures are contained within other structures, +; such as the FNODE. When the B+TREE is more than one level, +; though, the non-root nodes are each held in a sector. +; +; This structure defines that format +; + +ALSEC struc + AS_SIG dd ? ; signature + AS_SEC dd ? ; sector # of this sector + AS_RENT dd ? ; parent sector # or FNODE # + AS_ALBLK db (size ALBLK) dup (?) ; ALBLK goes here + ; ALNODE or ALLEAF records start here +ALSEC ends + +; # of bytes available for ALLEAF or ALNODE values. Size chosen +; so an integral # of either structure fits + +ifdef MASM +ASSIZ equ ((SECSIZE - size ALSEC)/24*24) + .errnz size ALLEAF-12 + .errnz size ALNODE-8 + .errnz (ASSIZ + AL_LOF + size AL_LOF + size ALBLK) GT 512 ; extra room for an AL_LOF value +else +ASSIZ equ ((SECSIZE - size ALSEC)/24*24) +endif + + +; AuxInfo Structure +; +; The FNODE contains two AuxInfo structures, one for ACLs and +; one for EAs. +; +; These structures point to within FNODE storage and also +; potentially point to an overflow area which is an ALBLK structure. +; The AI_FNL stuff is stored in the FN_FREE area, the ACLs first +; and the EAs second, any free space following. The start of the +; EAs can be found by offseting FN_FREE with FN_ACL.AI_FNL +; + +AUXINFO struc + AI_DAL dd ? ; non-fnode Disk Allocation length + AI_SEC dd ? ; sec # of first sec in extent or of ALSEC + AI_FNL dw ? ; length of fnode info + AI_DAT db ? ; non-zero if AI_SEC points to ALSEC +AUXINFO ends + +;* Fnode block definition +; +; Every file and directory has an FNODE. The file location +; stuff is only used for files; directories are kept in +; a BTREE of DIRBLK records pointed to by FN_SEC[0].RSEC +; + +ALCNT equ 8 ; 8 ALLEAF records in an FN_AT entry +LEAFPERFNODE equ 8 ; 8 ALLEAF records in an FN_AT entry +NODEPERFNODE equ 12 ; 12 ALNODE records in an FNODE. +LEAFPERSEC equ 40 ; ALLEAF records in an allocation sector +NODEPERSEC equ 60 ; ALNODE records in an allocation sector + +FNODE struc + +; The following file location information is copied into the OFT +; and is used there during normal file access. The stuff in the +; fnode record here may in fact be out of date for open files. +; See the OFN_ in the OFT structure THESE TWO AREAS IN THE +; RESPECTIVE RECORDS MUST HAVE IDENTICAL FORMATS. +; +; There are two kinds of location info: FNSCNT SPTR records +; and then a single, double, triple, and quad indirect block pointer. +; The "block threshold" means the first sector number which is +; contained in that indirect block heirarchy. You use this +; to quickly find out where to start looking. +; + + FN_SIG dd ? ; signature value + +; History tracking info for softer software + + FN_SRH dd ? ; sequential read history + FN_FRH dd ? ; fast read history + FN_NAME db 16 dup (?) ; 1st 18 bytes of file name + FN_CONTFN dd ? ; fnode of directory cont. this file/dir + +; stuff not interesting once opened + + FN_ACL db (size AUXINFO) dup (?) ; access ctl list aux info structure + FN_HCNT db ? ; count of valid history bits + FN_EA db (size AUXINFO) dup (?) ; ea aux info structure + FN_FLAG db ? ; FNODE flag byte + + FN_AB db (size ALBLK) dup (?) ; allocation block structure + FN_ALREC db (ALCNT*size ALLEAF) dup (?) ; referenced from FN_AB + FN_VLEN dd ? ; length of valid data in file. if DIR_SIZE + ; is > FN_VLEN then the space inbetween + ; must be zapped before being shown to user + FN_NEACNT dd ? ; # of "need eas" in file + +; The following fields are unused in this release, they're for +; future compatibility. When deleting files, if FN_EEL is non-zero +; then FN_EEL sectors starting at FN_EEP must be released too. +; + + FN_UID db 16 dup (?) ; reserved for UID value + FN_ACLBASE dw ? ; FN_ACLBASE offset of 1st ACE in fnode + FN_SPARE db 10 dup (?); 10 more bytes emergency spares + +; Free pool. ACLs and EAs are stored here via the AUXINFO structure + + FN_FREE db 316 dup (?) ; free space for perm and env list; perm list + ; comes first. +FNODE ends + + +ifdef MASM + .errnz AL_LOF ; verify validity of FN_DMY1 hack above + .errnz size AL_LOF-4 +endif + +; Fnode FN_FLAG bits + +FNF_DIR equ 01h ; is a directory fnode |