BSD 4_4 release

[unix-history] / usr / src / sys / vax / vax / mscp.h

diff --git a/usr/src/sys/vax/vax/mscp.h b/usr/src/sys/vax/vax/mscp.h
index 0bdca8f..d072ebc 100644 (file)
--- a/usr/src/sys/vax/vax/mscp.h
+++ b/usr/src/sys/vax/vax/mscp.h
@@ -1,314 +1,470 @@
-/*     mscp.h  6.2     84/06/27        */
+/*
+ * Copyright (c) 1988 Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *     This product includes software developed by the University of
+ *     California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)mscp.h      7.5 (Berkeley) 6/28/90
+ */

 
 /*
  * Definitions for the Mass Storage Control Protocol
 
 /*
  * Definitions for the Mass Storage Control Protocol

+ * I WISH I KNEW WHAT MORE OF THESE WERE.  IT SURE WOULD BE NICE
+ * IF DEC SOLD DOCUMENTATION FOR THEIR OWN CONTROLLERS.

  */
 
  */
 

-

 /*
  * Control message opcodes
  */
 /*
  * Control message opcodes
  */

-#define        M_OP_ABORT      0001    /* Abort command */
-#define        M_OP_GTCMD      0002    /* Get command status command */
-#define        M_OP_GTUNT      0003    /* Get unit status command */
-#define        M_OP_STCON      0004    /* Set controller characteristics command */
-#define        M_OP_SEREX      0007    /* Serious exception end message */
-#define        M_OP_AVAIL      0010    /* Available command */
-#define        M_OP_ONLIN      0011    /* Online command */
-#define        M_OP_STUNT      0012    /* Set unit characteristics command */
-#define        M_OP_DTACP      0013    /* Determine access paths command */
-#define        M_OP_ACCES      0020    /* Access command */
-#define        M_OP_CMPCD      0021    /* Compare controller data command */
-#define        M_OP_ERASE      0022    /* Erase command */
-#define        M_OP_FLUSH      0023    /* Flush command */
-#define        M_OP_REPLC      0024    /* Replace command */
-#define        M_OP_COMP       0040    /* Compare host data command */
-#define        M_OP_READ       0041    /* Read command */
-#define        M_OP_WRITE      0042    /* Write command */
-#define        M_OP_AVATN      0100    /* Available attention message */
-#define        M_OP_DUPUN      0101    /* Duplicate unit number attention message */
-#define        M_OP_ACPTH      0102    /* Access path attention message */
-#define        M_OP_END        0200    /* End message flag */
+#define        M_OP_ABORT      0x01    /* Abort command */
+#define        M_OP_GETCMDST   0x02    /* Get command status command */
+#define        M_OP_GETUNITST  0x03    /* Get unit status command */
+#define        M_OP_SETCTLRC   0x04    /* Set controller characteristics command */
+#define        M_OP_SEREX      0x07    /* Serious exception end message */
+#define        M_OP_AVAILABLE  0x08    /* Available command */
+#define        M_OP_ONLINE     0x09    /* Online command */
+#define        M_OP_SETUNITC   0x0a    /* Set unit characteristics command */
+#define        M_OP_DTACCPATH  0x0b    /* Determine access paths command */
+#define        M_OP_ACCESS     0x10    /* Access command */
+#define        M_OP_COMPCD     0x11    /* Compare controller data command */
+#define        M_OP_ERASE      0x12    /* Erase command */
+#define        M_OP_FLUSH      0x13    /* Flush command */
+#define        M_OP_REPLACE    0x14    /* Replace command */
+#define        M_OP_COMPHD     0x20    /* Compare host data command */
+#define        M_OP_READ       0x21    /* Read command */
+#define        M_OP_WRITE      0x22    /* Write command */
+#define        M_OP_AVAILATTN  0x40    /* Available attention message */
+#define        M_OP_DUPUNIT    0x41    /* Duplicate unit number attention message */
+#define        M_OP_ACCPATH    0x42    /* Access path attention message */
+#define        M_OP_END        0x80    /* End message flag */

 
 
 /*
  * Generic command modifiers
  */
 
 
 /*
  * Generic command modifiers
  */

-#define        M_MD_EXPRS      0100000         /* Express request */
-#define        M_MD_COMP       0040000         /* Compare */
-#define        M_MD_CLSEX      0020000         /* Clear serious exception */
-#define        M_MD_ERROR      0010000         /* Force error */
-#define        M_MD_SCCHH      0004000         /* Suppress caching (high speed) */
-#define        M_MD_SCCHL      0002000         /* Suppress caching (low speed) */
-#define        M_MD_SECOR      0001000         /* Suppress error correction */
-#define        M_MD_SEREC      0000400         /* Suppress error recovery */
-#define        M_MD_SSHDW      0000200         /* Suppress shadowing */
-#define        M_MD_WBKNV      0000100         /* Write back (non-volatile) */
-#define        M_MD_WBKVL      0000040         /* Write back (volatile) */
-#define        M_MD_WRSEQ      0000020         /* Write shadow set one unit at a time */
+#define        M_MD_EXPRS      0x8000  /* Express request */
+#define        M_MD_COMP       0x4000  /* Compare */
+#define        M_MD_CLSEX      0x2000  /* Clear serious exception */
+#define        M_MD_ERROR      0x1000  /* Force error */
+#define        M_MD_SCCHH      0x0800  /* Suppress caching (high speed) */
+#define        M_MD_SCCHL      0x0400  /* Suppress caching (low speed) */
+#define        M_MD_SECOR      0x0200  /* Suppress error correction */
+#define        M_MD_SEREC      0x0100  /* Suppress error recovery */
+#define        M_MD_SSHDW      0x0080  /* Suppress shadowing */
+#define        M_MD_WBKNV      0x0040  /* Write back (non-volatile) */
+#define        M_MD_WBKVL      0x0020  /* Write back (volatile) */
+#define        M_MD_WRSEQ      0x0010  /* Write shadow set one unit at a time */

 
 /*
  * AVAILABLE command modifiers
  */
 
 /*
  * AVAILABLE command modifiers
  */

-#define        M_MD_ALLCD      0000002         /* All class drivers */
-#define        M_MD_SPNDW      0000001         /* Spin down */
+#define        M_AVM_ALLCD     0x0002  /* All class drivers */
+#define        M_AVM_SPINDOWN  0x0001  /* Spin down */

 
 /*
  * FLUSH command modifiers
  */
 
 /*
  * FLUSH command modifiers
  */

-#define        M_MD_FLENU      0000001         /* Flush entire unit */
-#define        M_MD_VOLTL      0000002         /* Volatile only */
+#define        M_FLM_FLUSHENU  0x0001  /* Flush entire unit */
+#define        M_FLM_VOLATILE  0x0002  /* Volatile only */

 
 /*
  * GET UNIT STATUS command modifiers
  */
 
 /*
  * GET UNIT STATUS command modifiers
  */

-#define        M_MD_NXUNT      0000001         /* Next unit */
+#define        M_GUM_NEXTUNIT  0x0001  /* Next unit */

 
 /*
  * ONLINE command modifiers
  */
 
 /*
  * ONLINE command modifiers
  */

-#define        M_MD_RIP        0000001         /* Allow self destruction */
-#define        M_MD_IGNMF      0000002         /* Ignore media format error */
+#define        M_OLM_RIP       0x0001  /* Allow self destruction */
+#define        M_OLM_IGNMF     0x0002  /* Ignore media format error */

 
 /*
  * ONLINE and SET UNIT CHARACTERISTICS command modifiers
  */
 
 /*
  * ONLINE and SET UNIT CHARACTERISTICS command modifiers
  */

-#define        M_MD_ALTHI      0000040         /* Alter host identifier */
-#define        M_MD_SHDSP      0000020         /* Shadow unit specified */
-#define        M_MD_CLWBL      0000010         /* Clear write-back data lost */
-#define        M_MD_STWRP      0000004         /* Set write protect */
+#define        M_OSM_ALTERHI   0x0020  /* Alter host identifier */
+#define        M_OSM_SHADOWSP  0x0010  /* Shadow unit specified */
+#define        M_OSM_CLEARWBL  0x0008  /* Clear write-back data lost */
+#define        M_OSM_SETWRPROT 0x0004  /* Set write protect */

 
 /*
  * REPLACE command modifiers
  */
 
 /*
  * REPLACE command modifiers
  */

-#define        M_MD_PRIMR      0000001         /* Primary replacement block */
-
+#define        M_RPM_PRIMARY   0x0001  /* Primary replacement block */

 
 /*
  * End message flags
  */
 
 /*
  * End message flags
  */

-#define        M_EF_BBLKR      0200    /* Bad block reported */
-#define        M_EF_BBLKU      0100    /* Bad block unreported */
-#define        M_EF_ERLOG      0040    /* Error log generated */
-#define        M_EF_SEREX      0020    /* Serious exception */
-
+#define        M_EF_BBLKR      0x80    /* Bad block reported */
+#define        M_EF_BBLKU      0x40    /* Bad block unreported */
+#define        M_EF_ERLOG      0x20    /* Error log generated */
+#define        M_EF_SEREX      0x10    /* Serious exception */

 
 /*
  * Controller flags
  */
 
 /*
  * Controller flags
  */

-#define        M_CF_ATTN       0200    /* Enable attention messages */
-#define        M_CF_MISC       0100    /* Enable miscellaneous error log messages */
-#define        M_CF_OTHER      0040    /* Enable other host's error log messages */
-#define        M_CF_THIS       0020    /* Enable this host's error log messages */
-#define        M_CF_MLTHS      0004    /* Multi-host */
-#define        M_CF_SHADW      0002    /* Shadowing */
-#define        M_CF_576        0001    /* 576 byte sectors */
-
+#define        M_CF_ATTN       0x80    /* Enable attention messages */
+#define        M_CF_MISC       0x40    /* Enable miscellaneous error log messages */
+#define        M_CF_OTHER      0x20    /* Enable other host's error log messages */
+#define        M_CF_THIS       0x10    /* Enable this host's error log messages */
+#define        M_CF_MLTHS      0x04    /* Multi-host */
+#define        M_CF_SHADW      0x02    /* Shadowing */
+#define        M_CF_576        0x01    /* 576 byte sectors */

 
 /*
  * Unit flags
  */
 
 /*
  * Unit flags
  */

-#define        M_UF_REPLC      0100000         /* Controller initiated bad block replacement */
-#define        M_UF_INACT      0040000         /* Inactive shadow set unit */
-#define        M_UF_WRTPH      0020000         /* Write protect (hardware) */
-#define        M_UF_WRTPS      0010000         /* Write protect (software or volume) */
-#define        M_UF_SCCHH      0004000         /* Suppress caching (high speed) */
-#define        M_UF_SCCHL      0002000         /* Suppress caching (low speed) */
-#define        M_UF_RMVBL      0000200         /* Removable media */
-#define        M_UF_WBKNV      0000100         /* Write back (non-volatile) */
-#define        M_UF_576        0000004         /* 576 byte sectors */
-#define        M_UF_CMPWR      0000002         /* Compare writes */
-#define        M_UF_CMPRD      0000001         /* Compare reads */
+#define        M_UF_REPLC      0x8000  /* Controller initiated bad block replacement */
+#define        M_UF_INACT      0x4000  /* Inactive shadow set unit */
+#define        M_UF_WRTPH      0x2000  /* Write protect (hardware) */
+#define        M_UF_WRTPS      0x1000  /* Write protect (software or volume) */
+#define        M_UF_SCCHH      0x8000  /* Suppress caching (high speed) */
+#define        M_UF_SCCHL      0x4000  /* Suppress caching (low speed) */
+#define        M_UF_RMVBL      0x0080  /* Removable media */
+#define        M_UF_WBKNV      0x0040  /* Write back (non-volatile) */
+#define        M_UF_576        0x0004  /* 576 byte sectors */
+#define        M_UF_CMPWR      0x0002  /* Compare writes */
+#define        M_UF_CMPRD      0x0001  /* Compare reads */

 
 

+/*
+ * Error Log message format codes
+ */
+#define        M_FM_CTLRERR    0x00    /* Controller error */
+#define        M_FM_BUSADDR    0x01    /* Host memory access error */
+#define        M_FM_DISKTRN    0x02    /* Disk transfer error */
+#define        M_FM_SDI        0x03    /* SDI error */
+#define        M_FM_SMLDSK     0x04    /* Small disk error */
+
+/*
+ * Error Log message flags
+ */
+#define        M_LF_SUCC       0x80    /* Operation successful */
+#define        M_LF_CONT       0x40    /* Operation continuing */
+#define        M_LF_SQNRS      0x01    /* Sequence number reset */

 
 /*
  * Status codes
  */
 
 /*
  * Status codes
  */

-#define        M_ST_MASK       037             /* Status code mask */
-#define        M_ST_SUCC       000             /* Success */
-#define        M_ST_ICMD       001             /* Invalid command */
-#define        M_ST_ABRTD      002             /* Command aborted */
-#define        M_ST_OFFLN      003             /* Unit offline */
-#define        M_ST_AVLBL      004             /* Unit available */
-#define        M_ST_MFMTE      005             /* Media format error */
-#define        M_ST_WRTPR      006             /* Write protected */
-#define        M_ST_COMP       007             /* Compare error */
-#define        M_ST_DATA       010             /* Data error */
-#define        M_ST_HSTBF      011             /* Host buffer access error */
-#define        M_ST_CNTLR      012             /* Controller error */
-#define        M_ST_DRIVE      013             /* Drive error */
-#define        M_ST_DIAG       037             /* Message from an internal diagnostic */
+#define        M_ST_MASK       0x1f    /* Status code mask */
+#define        M_ST_SUCCESS    0x00    /* Success */
+#define        M_ST_INVALCMD   0x01    /* Invalid command */
+#define        M_ST_ABORTED    0x02    /* Command aborted */
+#define        M_ST_OFFLINE    0x03    /* Unit offline */
+#define        M_ST_AVAILABLE  0x04    /* Unit available */
+#define        M_ST_MFMTERR    0x05    /* Media format error */
+#define        M_ST_WRPROT     0x06    /* Write protected */
+#define        M_ST_COMPERR    0x07    /* Compare error */
+#define        M_ST_DATAERR    0x08    /* Data error */
+#define        M_ST_HOSTBUFERR 0x09    /* Host buffer access error */
+#define        M_ST_CTLRERR    0x0a    /* Controller error */
+#define        M_ST_DRIVEERR   0x0b    /* Drive error */
+#define        M_ST_DIAG       0x1f    /* Message from an internal diagnostic */

 
 /*
 
 /*

- * An MSCP packet
+ * Subcodes of M_ST_OFFLINE

  */
  */

+#define        M_OFFLINE_UNKNOWN       (0 << 5) /* unknown or on other ctlr */
+#define        M_OFFLINE_UNMOUNTED     (1 << 5) /* unmounted or RUN/STOP at STOP */
+#define        M_OFFLINE_INOPERATIVE   (2 << 5) /* inoperative? */
+#define        M_OFFLINE_DUPLICATE     (4 << 5) /* duplicate unit number */
+#define        M_OFFLINE_INDIAGNOSTIC  (8 << 5) /* disabled by FS or diagnostic */

 
 

-struct mscp {
-       struct  mscp_header mscp_header;/* device specific header */
-       long    mscp_cmdref;            /* command reference number */
-       short   mscp_unit;              /* unit number */
-       short   mscp_xxx1;              /* unused */
-       u_char  mscp_opcode;            /* opcode */
-       u_char  mscp_flags;             /* end message flags */
-       short   mscp_modifier;          /* modifiers */
-       union {
-       struct {
-               long    Mscp_bytecnt;   /* byte count */
-               long    Mscp_buffer;    /* buffer descriptor */
-               long    Mscp_xxx2[2];   /* unused */
-               long    Mscp_lbn;       /* logical block number */
-               long    Mscp_xxx4;      /* unused */
-               long    *Mscp_dscptr;   /* pointer to descriptor (software) */
-               long    Mscp_sftwds[4]; /* software words, padding */
-       } mscp_generic;
-       struct {
-               short   Mscp_version;   /* MSCP version */
-               short   Mscp_cntflgs;   /* controller flags */
-               short   Mscp_hsttmo;    /* host timeout */
-               short   Mscp_usefrac;   /* use fraction */
-               long    Mscp_time;      /* time and date */
-       } mscp_setcntchar;
-       struct {
-               short   Mscp_multunt;   /* multi-unit code */
-               short   Mscp_unitflgs;  /* unit flags */
-               long    Mscp_hostid;    /* host identifier */
-               quad    Mscp_unitid;    /* unit identifier */
-               long    Mscp_mediaid;   /* media type identifier */
-               short   Mscp_shdwunt;   /* shadow unit */
-               short   Mscp_shdwsts;   /* shadow status */
-               short   Mscp_track;     /* track size */
-               short   Mscp_group;     /* group size */
-               short   Mscp_cylinder;  /* cylinder size */
-               short   Mscp_xxx3;      /* reserved */
-               short   Mscp_rctsize;   /* RCT table size */
-               char    Mscp_rbns;      /* RBNs / track */
-               char    Mscp_rctcpys;   /* RCT copies */
-       } mscp_getunitsts;
-       } mscp_un;
-       short mscp_fil1;
-       short mscp_fil2;
-       short mscp_fil3;
+/*
+ * An MSCP packet begins with a header giving the length of
+ * the entire packet (including the header itself)(?), two bytes
+ * of device specific data, and the a whole bunch of variants
+ * depending on message type.
+ *
+ * N.B.:  In most cases we distinguish between a `command' and
+ * an `end' variant as well.  The command variant is that which
+ * is given to the controller; the `end' variant is its response.
+ */
+
+/*
+ * Generic sequential message variant (command and response).
+ */
+struct mscpv_seq {
+       long    seq_bytecount;          /* byte count */
+#define        seq_rbn         seq_bytecount   /* aka RBN (replace) */
+#define        seq_outref      seq_bytecount   /* aka outref (abort/get cmd status) */
+       long    seq_buffer;             /* buffer descriptor */
+       long    seq_mapbase;            /* page map (first PTE) phys address */
+       long    seq_xxx1;       /* ? */ /* unused */
+       long    seq_lbn;                /* logical block number */
+       long    seq_xxx2;       /* ? */ /* unused */
+       long    *seq_addr;              /* pointer to cmd descriptor */
+       long    seq_software[4];        /* reserved to software; unused */

 };
 
 };
 

-#define mscp_msglen (sizeof (struct mscp) - sizeof(struct mscp_header))
+/*
+ * Set Controller Characteristics command variant
+ */
+struct mscpv_sccc {
+       u_short sccc_version;           /* MSCP version number */
+       u_short sccc_ctlrflags;         /* controller flags */
+       u_short sccc_hosttimo;          /* host timeout */
+       u_short sccc_usefrac;           /* use fraction */
+       long    sccc_time;              /* time and date */
+       long    sccc_xxx1;      /* ? */
+       long    sccc_errlgfl;   /* ? */
+       short   sccc_xxx2;      /* ? */
+       short   sccc_copyspd;   /* ? */
+};

 
 /*
 
 /*

- * generic packet
+ * Set Controller Characteristics end variant

  */
  */

+struct mscpv_scce {
+       u_short scce_version;           /* MSCP version number */
+       u_short scce_ctlrflags;         /* controller flags */
+       u_short scce_ctlrtimo;          /* controller timeout */
+       u_short scce_ctlrcmdl;          /* ??? */
+       quad    scce_ctlrid;            /* controller ID */
+       long    scce_xxx[3];    /* ? */
+       long    scce_volser;            /* volume serial number */
+};

 
 

-#define        mscp_bytecnt    mscp_un.mscp_generic.Mscp_bytecnt
-#define        mscp_buffer     mscp_un.mscp_generic.Mscp_buffer
-#define        mscp_lbn        mscp_un.mscp_generic.Mscp_lbn
-#define        mscp_dscptr     mscp_un.mscp_generic.Mscp_dscptr
-#define        mscp_sftwds     mscp_un.mscp_generic.Mscp_sftwds
-#define        mscp_status     mscp_modifier
+/*
+ * On Line command variant
+ */
+struct mscpv_onlc {
+       long    onlc_xxx1[4];   /* ? */
+       long    onlc_errlgfl;           /* error log flag? */
+       short   onlc_xxx2;      /* ? */
+       short   onlc_copyspd;           /* copy speed? */
+};

 
 /*
 
 /*

- * Abort / Get Command Status packet
+ * On Line end variant

  */
  */

+struct mscpv_onle {
+       long    onle_xxx1[3];   /* ? */
+/*???*/        short   onle_xxx2;      /* ? */
+       u_char  onle_drivetype;         /* drive type index (same in guse) */
+       char    onle_xxx3;      /* ? */
+       long    onle_mediaid;           /* media type id (same in guse) */
+       long    onle_xxx4;      /* ? */
+       long    onle_unitsize;          /* unit size in sectors */
+       long    onle_volser;            /* volume serial number */
+};

 
 

-#define        mscp_outref     mscp_bytecnt
+/*
+ * Get Unit Status end variant (and Avail Attn?)
+ */
+struct mscpv_guse {
+       u_short guse_multunit;          /* multi-unit code */
+       u_short guse_unitflags;         /* unit flags */
+       long    guse_hostid;            /* host id */
+       long    guse_unitid0;   /*???*/
+       short   guse_unitid1;   /*???*/
+       u_char  guse_drivetype;         /* drive type index */
+       u_char  guse_unitid2;   /*???*/
+       long    guse_mediaid;           /* media type id (encoded) */
+       short   guse_shadowunit;        /* shadow unit */
+       short   guse_shadowstat;        /* shadow status */
+       u_short guse_nspt;              /* sectors per track */
+       u_short guse_group;             /* track group size */
+       u_short guse_ngpc;              /* groups per cylinder */
+       u_short guse_xxx;               /* reserved */
+       u_short guse_rctsize;           /* RCT size (sectors) */
+       u_char  guse_nrpt;              /* RBNs per track */
+       u_char  guse_nrct;              /* number of RCTs */
+};

 
 /*
 
 /*

- * Online / Set Unit Characteristics packet
+ * Macros to break up and build media IDs.  An ID encodes the port
+ * type in the top 10 bits, and the drive type in the remaining 22.
+ * The 10 bits, and 15 of the 22, are in groups of 5, with the value
+ * 0 representing space and values 1..26 representing A..Z.  The low
+ * 7 bits represent a number in 0..127.  Hence an RA81 on a UDA50
+ * is <D><U><R><A>< >81, or 0x25641051.  This encoding scheme is known
+ * in part in uda.c.
+ *
+ * The casts below are just to make pcc generate better code.

  */
  */

+#define        MSCP_MEDIA_PORT(id)     (((long)(id) >> 22) & 0x3ff)    /* port */
+#define        MSCP_MEDIA_DRIVE(id)    ((long)(id) & 0x003fffff)       /* drive */
+#define        MSCP_MID_ECH(n, id)     (((long)(id) >> ((n) * 5 + 7)) & 0x1f)
+#define        MSCP_MID_CHAR(n, id) \
+       (MSCP_MID_ECH(n, id) ? MSCP_MID_ECH(n, id) + '@' : ' ')
+#define        MSCP_MID_NUM(id)        ((id) & 0x7f)
+/* for, e.g., RA81 */
+#define        MSCP_MKDRIVE2(a, b, n) \
+       (((a) - '@') << 17 | ((b) - '@') << 12 | (n))
+/* for, e.g., RRD50 */
+#define        MSCP_MKDRIVE3(a, b, c, n) \
+       (((a) - '@') << 17 | ((b) - '@') << 12 | ((c) - '@') << 7 | (n))

 
 

-#define        mscp_errlgfl    mscp_lbn
-#define        mscp_copyspd    mscp_shdwsts
+/*
+ * Error datagram variant.
+ */
+struct mscpv_erd {
+       quad    erd_ctlrid;             /* controller ID */
+       u_char  erd_ctlrsoftware;       /* controller software version */
+       u_char  erd_ctlrhardware;       /* controller hardware version */
+       u_short erd_multiunit;          /* multi-unit code (?) */
+       union {
+               u_long  un_busaddr;     /* bus address, if mem access err */
+               quad    un_unitid;      /* unit id, otherwise */
+       } erd_un1;
+#define        erd_busaddr     erd_un1.un_busaddr
+#define        erd_unitid      erd_un1.un_unitid
+       u_char  erd_unitsoftware;       /* unit software version */
+       u_char  erd_unithardware;       /* unit hardware version */
+       union {
+               u_char  un_b[2];        /* level, retry (if disk xfer err) */
+               u_short un_s;           /* cylinder (if small disk error) */
+       } erd_un2;
+#define        erd_level       erd_un2.un_b[0]
+#define        erd_retry       erd_un2.un_b[1]
+#define        erd_sdecyl      erd_un2.un_s
+       long    erd_volser;             /* volume serial number */
+       u_long  erd_hdr;                /* `header' (block number) */
+       u_char  erd_sdistat[12];        /* SDI status information (?) */
+};

 
 /*
 
 /*

- * Replace packet
+ * I am making brash assumptions about the first four bytes of all
+ * MSCP packets.  These appear to be true for both UDA50s and TMSCP
+ * devices (TU81, TA81, TK50).  DEC claim that these four bytes are
+ * not part of MSCP itself, yet at least the length is necessary
+ * for, e.g., error checking.

  */
  */

+struct mscp {
+       u_short mscp_msglen;            /* length in bytes */
+       u_char  mscp_msgtc;             /* type (high 4 bits) and credits */
+       u_char  mscp_vcid;              /* virtual circuit ID */
+       long    mscp_cmdref;            /* command reference number */
+       u_short mscp_unit;              /* unit number */
+       u_short mscp_seqnum;            /* sequence number */
+       u_char  mscp_opcode;            /* opcode */
+#define        mscp_format     mscp_opcode     /* aka format (datagrams) */
+       u_char  mscp_flags;             /* flags */
+       u_short mscp_modifier;          /* modifier (commands) */
+#define        mscp_status     mscp_modifier   /* aka status (ends) */
+#define        mscp_event      mscp_modifier   /* aka event (datagrams) */
+       union {
+               struct  mscpv_seq un_seq;       /* generic sequential msg */
+               struct  mscpv_sccc un_sccc;     /* SCC command */
+               struct  mscpv_scce un_scce;     /* SCC end */
+               struct  mscpv_onlc un_onlc;     /* on line command */
+               struct  mscpv_onle un_onle;     /* on line end */
+               struct  mscpv_guse un_guse;     /* get unit status */
+               struct  mscpv_erd un_erd;       /* error datagram */
+       } mscp_un;
+/*???*/        long    mscp_xxx;               /* pad to 64 bytes */
+};

 
 

-#define        mscp_rbn        mscp_bytecnt
+/*
+ * Define message length according to the DEC specifications by dropping
+ * the four byte header.
+ */
+#define        MSCP_MSGLEN     (sizeof (struct mscp) - 4)

 
 /*
 
 /*

- * Set Controller Characteristics packet
+ * Shorthand

  */
 
  */
 

-#define        mscp_version    mscp_un.mscp_setcntchar.Mscp_version
-#define        mscp_cntflgs    mscp_un.mscp_setcntchar.Mscp_cntflgs
-#define        mscp_hsttmo     mscp_un.mscp_setcntchar.Mscp_hsttmo
-#define        mscp_usefrac    mscp_un.mscp_setcntchar.Mscp_usefrac
-#define        mscp_time       mscp_un.mscp_setcntchar.Mscp_time
+/*
+ * Generic packet
+ */
+#define        mscp_seq        mscp_un.un_seq

 
 /*
 
 /*

- * Get Unit Status end packet
+ * Set Controller Characteristics packet

  */
  */

+#define        mscp_sccc       mscp_un.un_sccc

 
 

-#define        mscp_multunt    mscp_un.mscp_getunitsts.Mscp_multunt
-#define        mscp_unitflgs   mscp_un.mscp_getunitsts.Mscp_unitflgs
-#define        mscp_hostid     mscp_un.mscp_getunitsts.Mscp_hostid
-#define        mscp_unitid     mscp_un.mscp_getunitsts.Mscp_unitid
-#define        mscp_mediaid    mscp_un.mscp_getunitsts.Mscp_mediaid
-#define        mscp_shdwunt    mscp_un.mscp_getunitsts.Mscp_shdwunt
-#define        mscp_shdwsts    mscp_un.mscp_getunitsts.Mscp_shdwsts
-#define        mscp_track      mscp_un.mscp_getunitsts.Mscp_track
-#define        mscp_group      mscp_un.mscp_getunitsts.Mscp_group
-#define        mscp_cylinder   mscp_un.mscp_getunitsts.Mscp_cylinder
-#define        mscp_rctsize    mscp_un.mscp_getunitsts.Mscp_rctsize
-#define        mscp_rbns       mscp_un.mscp_getunitsts.Mscp_rbns
-#define        mscp_rctcpys    mscp_un.mscp_getunitsts.Mscp_rctcpys
+/*
+ * Set Controller Characteristics end packet
+ */
+#define        mscp_scce       mscp_un.un_scce

 
 /*
 
 /*

- * Online / Set Unit Characteristics end packet
+ * Online / Set Unit Characteristics command packet

  */
  */

+#define        mscp_onlc       mscp_un.un_onlc

 
 

-#define        mscp_untsize    mscp_dscptr
-#define        mscp_volser     mscp_sftwds[0]
+/*
+ * Online end packet
+ */
+#define        mscp_onle       mscp_un.un_onle

 
 /*
 
 /*

- * Set Controller Characteristics end packet
+ * Get Unit Status end packet

  */
  */

+#define        mscp_guse       mscp_un.un_guse

 
 

-#define        mscp_cnttmo     mscp_hsttmo
-#define        mscp_cntcmdl    mscp_usefrac
-#define        mscp_cntid      mscp_unitid
+/*
+ * MSCP Error Log packet
+ */
+#define        mscp_erd        mscp_un.un_erd

 
 

+/*
+ * MSCP seq_addr field actually belongs to overall packet.
+ */
+#define        mscp_addr       mscp_seq.seq_addr

 
 /*
 
 /*

- * Error Log message format codes
+ * Macros to break up mscp_msgtc, and types.

  */
  */

-#define        M_FM_CNTERR     0       /* Controller error */
-#define        M_FM_BUSADDR    1       /* Host memory access error */
-#define        M_FM_DISKTRN    2       /* Disk transfer error */
-#define        M_FM_SDI        3       /* SDI error */
-#define        M_FM_SMLDSK     4       /* Small disk error */
+#define        MSCP_MSGTYPE(m) ((m) & 0xf0)
+#define        MSCP_CREDITS(m) ((m) & 0x0f)
+
+#define        MSCPT_SEQ               0x00    /* sequential message */
+#define        MSCPT_DATAGRAM          0x10    /* error datagram */
+#define        MSCPT_CREDITS           0x20    /* credit notification */
+#define        MSCPT_MAINTENANCE       0xf0    /* who knows */
+

 
 /*
 
 /*

- * Error Log message flags
+ * Here begin more perhaps brash assumptions about MSCP devices...

  */
  */

-#define        M_LF_SUCC       0200    /* Operation successful */
-#define        M_LF_CONT       0100    /* Operation continuing */
-#define        M_LF_SQNRS      0001    /* Sequence number reset */

 
 /*
 
 /*

- * MSCP Error Log packet
+ * MSCP controllers have `command rings' and `response rings'.  A
+ * command ring is a pool of MSCP packets that the host uses to give
+ * commands to the controller; a response ring is a pool of MSCP
+ * packets that the controller uses to give back responses.  Entries
+ * in the command and response rings are `owned' by either the host
+ * or the controller; only the owner is allowed to alter any of the
+ * fields in the MSCP packet.  Thus, free command packets are owned
+ * by the host, and free response packets by the controller.  When
+ * the host gives a packet to the controller, it tells the controller
+ * by touching a device register; when the controller gives a response
+ * to the host, it generates an interrupt if enabled, and sets
+ * a device register as well.

  *
  *

- *     NOTE: MSCP packet must be padded to this size.
- */
-
-struct mslg {
-       struct  mscp_header mslg_header;/* device specific header */
-       long    mslg_cmdref;            /* command reference number */
-       short   mslg_unit;              /* unit number */
-       short   mslg_seqnum;            /* sequence number */
-       u_char  mslg_format;            /* format */
-       u_char  mslg_flags;             /* error log message flags */
-       short   mslg_event;             /* event code */
-       quad    mslg_cntid;             /* controller id */
-       u_char  mslg_cntsvr;            /* controller software version */
-       u_char  mslg_cnthvr;            /* controller hardware version */
-       short   mslg_multunt;           /* multi-unit code */
-       quad    mslg_unitid;            /* unit id */
-       u_char  mslg_unitsvr;           /* unit software version */
-       u_char  mslg_unithvr;           /* unit hardware version */
-       short   mslg_group;             /* group; retry + level */
-       long    mslg_volser;            /* volume serial number */
-       long    mslg_hdr;               /* header */
-       char    mslg_sdistat[12];       /* SDI status information */
-};
-
-#define        mslg_busaddr    mslg_unitid.val[0]
-#define        mslg_sdecyl     mslg_group
-
+ * The pool is `described' by a set of pointers to the packets, along
+ * with the two flags below.
+ */
+#define        MSCP_OWN        0x80000000      /* controller owns this packet */
+#define        MSCP_INT        0x40000000      /* controller should interrupt */