openocd/src/helper/jep106.c
Antonio Borneo 7a61a006de jep106: use packed jedec manufacturer code
JEP106 encodes JEDEC-assigned manufacture code as:
a) a sequence of zero or more escape codes 0x7f;
b) an odd-parity bit of the next 7 bits;
c) 7 bits.

The same code is often represented as a single value composed by
the logical OR between:
- the number of escape codes in a), shifted left by 7 positions;
- the 7 bits in c).
This is the preferred packed representation used by this change.

Currently there are only two uses of JEP106 in openocd to get the
manufacturer name:
- to decode the JTAG IDCODE of each TAP, where the JEP106 code is
  already packed as in the preferred representation above in bits
  IDCODE[11:1];
- to decode the ARM CoreSight PIDR register, where the JEP106 code
  is split in 3 parts:
  = PIDR3[3:0], corresponding to bits [10:7] of the packed code;
  = PIDR2[2:0], corresponding to bits [6:4] of the packed code;
  = PIDR1[7:4], corresponding to bits [3:0] of the packed code.

Wrap the existing JEP106 decode function in a simpler API using
the packed code.
Simplify the callers by skipping the bit unpacking.
Change the manufacturer code in CoreSight table dap_partnums[] to
match the packed representation, by removing the always-one bit 7
erroneously taken from PIDR bit JEDEC and included in the former
table.

Change-Id: I63eb4da9e6801fab25e330f1f6b792d2fd619493
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6418
Tested-by: jenkins
2021-08-22 20:26:06 +00:00

45 lines
1.8 KiB
C

/***************************************************************************
* Copyright (C) 2015 Andreas Fritiofson *
* andreas.fritiofson@gmail.com *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
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* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "jep106.h"
#include "log.h"
static const char * const jep106[][126] = {
#include "jep106.inc"
};
const char *jep106_table_manufacturer(unsigned int bank, unsigned int id)
{
if (id < 1 || id > 126) {
LOG_DEBUG("BUG: Caller passed out-of-range JEP106 ID!");
return "<invalid>";
}
/* index is zero based */
id--;
if (bank >= ARRAY_SIZE(jep106) || jep106[bank][id] == 0)
return "<unknown>";
return jep106[bank][id];
}