mmd.c

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/************************************************************************************************************
*
* FILE    : mmd.c
*
* DATE    : $Date: 2004/07/23 11:57:45 $   $Revision: 1.4 $
* Original: 2004/05/28 14:05:35    Revision: 1.32      Tag: hcf7_t20040602_01
* Original: 2004/05/13 15:31:45    Revision: 1.30      Tag: hcf7_t7_20040513_01
* Original: 2004/04/15 09:24:42    Revision: 1.25      Tag: hcf7_t7_20040415_01
* Original: 2004/04/08 15:18:17    Revision: 1.24      Tag: t7_20040413_01
* Original: 2004/04/01 15:32:55    Revision: 1.22      Tag: t7_20040401_01
* Original: 2004/03/10 15:39:28    Revision: 1.18      Tag: t20040310_01
* Original: 2004/03/03 14:10:12    Revision: 1.16      Tag: t20040304_01
* Original: 2004/03/02 09:27:12    Revision: 1.14      Tag: t20040302_03
* Original: 2004/02/24 13:00:29    Revision: 1.12      Tag: t20040224_01
* Original: 2004/01/30 09:59:33    Revision: 1.11      Tag: t20040219_01
*
* AUTHOR  : Nico Valster
*
* DESC    : Common routines for HCF, MSF, UIL as well as USF sources
*
* Note: relative to Asserts, the following can be observed:
*   Since the IFB is not known inside the routine, the macro HCFASSERT is replaced with MDDASSERT.
*   Also the line number reported in the assert is raised by FILE_NAME_OFFSET (20000) to discriminate the
*   MMD Asserts from HCF and DHF asserts.
*
***************************************************************************************************************
*
*
* SOFTWARE LICENSE
*
* This software is provided subject to the following terms and conditions,
* which you should read carefully before using the software.  Using this
* software indicates your acceptance of these terms and conditions.  If you do
* not agree with these terms and conditions, do not use the software.
*
* COPYRIGHT © 2001 - 2004  by Agere Systems Inc.   All Rights Reserved
* All rights reserved.
*
* Redistribution and use in source or binary forms, with or without
* modifications, are permitted provided that the following conditions are met:
*
* . Redistributions of source code must retain the above copyright notice, this
*    list of conditions and the following Disclaimer as comments in the code as
*    well as in the documentation and/or other materials provided with the
*    distribution.
*
* . Redistributions in binary form must reproduce the above copyright notice,
*    this list of conditions and the following Disclaimer in the documentation
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*
* . Neither the name of Agere Systems Inc. nor the names of the contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
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*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, INFRINGEMENT AND THE IMPLIED WARRANTIES OF
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* USE, MODIFICATION OR DISTRIBUTION OF THIS SOFTWARE IS SOLELY AT THE USERS OWN
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**************************************************************************************************************/

#include "hcf.h"                // Needed as long as we do not really sort out the mess
#include "hcfdef.h"             // get CNV_LITTLE_TO_SHORT
#include "mmd.h"                // MoreModularDriver common include file

//to distinguish DHF from HCF asserts by means of line number
#undef  FILE_NAME_OFFSET
#define FILE_NAME_OFFSET DHF_FILE_NAME_OFFSET


/*************************************************************************************************************
*
*.MODULE        CFG_RANGE_SPEC_STRCT* mmd_check_comp( CFG_RANGES_STRCT *actp, CFG_SUP_RANGE_STRCT *supp )
*.PURPOSE       Checks compatibility between an actor and a supplier.
*
*.ARGUMENTS
*   actp
*   supp
*
*.RETURNS
*   NULL    incompatible
*   <>NULL  pointer to matching CFG_RANGE_SPEC_STRCT substructure in actor-structure matching the supplier
*
*.NARRATIVE
*
*  Parameters:
*   actp    address of the actor specification
*   supp    address of the supplier specification
*
*   Description: mmd_check_comp is a support routine to check the compatibility between an actor and a
*   supplier.  mmd_check_comp is independent of the endianness of the actp and supp structures. This is
*   achieved by checking the "bottom" or "role" fields of these structures. Since these fields are restricted
*   to a limited range, comparing the contents to a value with a known endian-ess gives a clue to their actual
*   endianness.
*
*.DIAGRAM
*1a: The role-field of the actor structure has a known non-zero, not "byte symmetric" value (namely
*   COMP_ROLE_ACT or 0x0001), so if and only the contents of this field matches COMP_ROLE_ACT (in Native
*   Endian format), the actor structure is Native Endian.
*2a: Since the role-field of the supplier structure is 0x0000, the test as used for the actor does not work
*   for a supplier. A supplier has always exactly 1 variant,top,bottom record with (officially, but see the
*   note below) each of these 3 values in the range 1 through 99, so one byte of the word value of variant,
*   top and bottom words is 0x00 and the other byte is non-zero. Whether the lowest address byte or the
*   highest address byte is non-zero depends on the Endianness of the LTV. If and only if the word value of
*   bottom is less than 0x0100, the supplier is Native Endian.
*   NOTE: the variant field of the supplier structure can not be used for the Endian Detection Algorithm,
*   because a a zero-valued variant has been used as Controlled Deployment indication in the past.
*   Note: An actor may have multiple sets of variant,top,bottom records, including dummy sets with variant,
*   top and bottom fields with a zero-value. As a consequence the endianness of the actor can not be determined
*   based on its variant,top,bottom values.
*
*   Note: the L and T field of the structures are always in Native Endian format, so you can not draw
*   conclusions concerning the Endianness of the structure based on these two fields.
*
*1b/2b
*   The only purpose of the CFG_RANGE_SPEC_BYTE_STRCT is to give easy access to the non-zero byte of the word
*   value of variant, top and bottom. The variables sup_endian and act_endian are used for the supplier and
*   actor structure respectively. These variables must be 0 when the structure has LE format and 1 if the
*   structure has BE format. This can be phrased as:
*   the variable is false (i.e 0x0000) if either
*       (the platform is LE and the LTV is the same as the platform)
*   or
*       (the platform is BE and the LTV differs from the platform).
*   the variable is true (i.e 0x0001) if either
*       (the platform is BE and the LTV is the same as the platform)
*   or
*       (the platform is LE and the LTV differs from the platform).
*
*   Alternatively this can be phrased as:
*   if the platform is LE
*       if the LTV is LE (i.e the same as the platform), then the variable = 0
*       else (the LTV is BE (i.e. different from the platform) ), then the variable = 1
*   if the platform is BE
*       if the LTV is BE (i.e the same as the platform), then the variable = 1
*       else (the LTV is LE (i.e. different from the platform) ), then the variable = 0
*
*   This is implemented as:
*   #if HCF_BIG_ENDIAN == 0 //platform is LE
*       sup/act_endian becomes reverse of structure-endianness as determined in 1a/1b
*   #endif
*6: Each of the actor variant-bottom-top records is checked against the (single) supplier variant-bottom-top
*   range till either an acceptable match is found or all actor records are tried. As explained above, due to
*   the limited ranges of these values, checking a byte is acceptable and suitable.
*8: depending on whether a match was found or not (as reflected by the value of the control variable of the
*   for loop), the NULL pointer or a pointer to the matching Number/Bottom/Top record of the Actor structure
*   is returned.
*   As an additional safety, checking the supplier length protects against invalid Supplier structures, which
*   may be caused by failing hcf_get_info (in which case the len-field is zero). Note that the contraption
*   "supp->len != sizeof(CFG_SUP_RANGE_STRCT)/sizeof(hcf_16) - 1"
*   did turn out not to work for a compiler which padded the structure definition.
*
* Note: when consulting references like DesignNotes and Architecture specifications there is a confusing use
*   of the notions number and variant. This resulted in an inconsistent use in the HCF nomenclature as well.
*   This makes the logic hard to follow and one has to be very much aware of the context when walking through
*   the code.
* NOTE: The Endian Detection Algorithm places limitations on future extensions of the fields, i.e. they should
*   stay within the currently defined boundaries of 1 through 99 (although 1 through 255) would work as well
*   and there should never be used a zero value for the bottom of a valid supplier.
* Note: relative to Asserts, the following can be observed:
*   1: Supplier variant 0x0000 has been used for Controlled Deployment
*   2: An actor may have one or more variant record specifications with a top of zero and a non-zero bottom
*   to override the HCF default support of a particular variant by the MSF programmer via hcfcfg.h
*   3:  An actor range can be specified as all zeros, e.g. as padding in the automatically generated firmware
*   image files.
*.ENDDOC                END DOCUMENTATION
*************************************************************************************************************/
CFG_RANGE_SPEC_STRCT*
mmd_check_comp( CFG_RANGES_STRCT *actp, CFG_SUP_RANGE_STRCT *supp )
{

CFG_RANGE_SPEC_BYTE_STRCT  *actq = (CFG_RANGE_SPEC_BYTE_STRCT*)actp->var_rec;
CFG_RANGE_SPEC_BYTE_STRCT  *supq = (CFG_RANGE_SPEC_BYTE_STRCT*)&(supp->variant);
hcf_16  i;
int     act_endian;                 //actor endian flag
int     sup_endian;                 //supplier endian flag

    act_endian = actp->role == COMP_ROLE_ACT;   //true if native endian             /* 1a */
    sup_endian = supp->bottom < 0x0100;         //true if native endian             /* 2a */

#if HCF_ASSERT
    MMDASSERT( supp->len == 6,                                                              supp->len )
    MMDASSERT( actp->len >= 6 && actp->len%3 == 0,                                          actp->len )

    if ( act_endian ) {                         //native endian
        MMDASSERT( actp->role == COMP_ROLE_ACT,                                             actp->role )
        MMDASSERT( 1 <= actp->id && actp->id <= 99,                                         actp->id )
    } else {                                    //non-native endian
        MMDASSERT( actp->role == CNV_END_SHORT(COMP_ROLE_ACT),                              actp->role )
        MMDASSERT( 1 <= CNV_END_SHORT(actp->id) && CNV_END_SHORT(actp->id) <= 99,               actp->id )
    }
    if ( sup_endian ) {                         //native endian
        MMDASSERT( supp->role == COMP_ROLE_SUPL,                                            supp->role )
        MMDASSERT( 1 <= supp->id      && supp->id <= 99,                                    supp->id )
        MMDASSERT( 1 <= supp->variant && supp->variant <= 99,                               supp->variant )
        MMDASSERT( 1 <= supp->bottom  && supp->bottom <= 99,                                supp->bottom )
        MMDASSERT( 1 <= supp->top     && supp->top <= 99,                                   supp->top )
        MMDASSERT( supp->bottom <= supp->top,                           supp->bottom << 8 | supp->top )
    } else {                                    //non-native endian
        MMDASSERT( supp->role == CNV_END_SHORT(COMP_ROLE_SUPL),                                 supp->role )
        MMDASSERT( 1 <= CNV_END_SHORT(supp->id) && CNV_END_SHORT(supp->id) <= 99,               supp->id )
        MMDASSERT( 1 <= CNV_END_SHORT(supp->variant) && CNV_END_SHORT(supp->variant) <= 99,     supp->variant )
        MMDASSERT( 1 <= CNV_END_SHORT(supp->bottom)  && CNV_END_SHORT(supp->bottom) <=99,       supp->bottom )
        MMDASSERT( 1 <= CNV_END_SHORT(supp->top)     && CNV_END_SHORT(supp->top) <=99,          supp->top )
        MMDASSERT( CNV_END_SHORT(supp->bottom) <= CNV_END_SHORT(supp->top), supp->bottom << 8 | supp->top )
    }
#endif // HCF_ASSERT

#if HCF_BIG_ENDIAN == 0
    act_endian = !act_endian;                                                                       /* 1b*/
    sup_endian = !sup_endian;                                                                       /* 2b*/
#endif // HCF_BIG_ENDIAN

    for ( i = actp->len ; i > 3; actq++, i -= 3 ) {                                                 /* 6 */
        MMDASSERT( actq->variant[act_endian] <= 99, i<<8 | actq->variant[act_endian] )
        MMDASSERT( actq->bottom[act_endian] <= 99 , i<<8 | actq->bottom[act_endian] )
        MMDASSERT( actq->top[act_endian] <= 99    , i<<8 | actq->top[act_endian] )
        MMDASSERT( actq->bottom[act_endian] <= actq->top[act_endian], i<<8 | actq->bottom[act_endian] )
        if ( actq->variant[act_endian] == supq->variant[sup_endian] &&
             actq->bottom[act_endian]  <= supq->top[sup_endian] &&
             actq->top[act_endian]     >= supq->bottom[sup_endian]
           ) break;
    }
    if ( i <= 3 || supp->len != 6 /*sizeof(CFG_SUP_RANGE_STRCT)/sizeof(hcf_16) - 1 */ ) {
       actq = NULL;                                                                                 /* 8 */
    }
#if HCF_ASSERT
    if ( actq == NULL ) {
        for ( i = 0; i <= supp->len; i += 2 ) {
            MMDASSERT( DO_ASSERT, MERGE_2( ((hcf_16*)supp)[i], ((hcf_16*)supp)[i+1] ) );
        }
        for ( i = 0; i <= actp->len; i += 2 ) {
            MMDASSERT( DO_ASSERT, MERGE_2( ((hcf_16*)actp)[i], ((hcf_16*)actp)[i+1] ) );
        }
    }
#endif // HCF_ASSERT
    return (CFG_RANGE_SPEC_STRCT*)actq;
} // mmd_check_comp