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Groups > comp.arch.embedded > #31867
| From | Niklas Holsti <niklas.holsti@tidorum.invalid> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Embedding a Checksum in an Image File |
| Date | 2023-04-28 01:10 +0300 |
| Organization | Tidorum Ltd |
| Message-ID | <kb0a5rFlvc6U1@mid.individual.net> (permalink) |
| References | <116ff07e-5e25-469a-90a0-9474108aadd3n@googlegroups.com> <105b1cab-9e5f-91b3-1de6-99586246ecbd@gmail.com> <b62a77f7-3a13-4d76-b7cb-c42902595751n@googlegroups.com> <u2emd2$22pgk$1@dont-email.me> |
On 2023-04-27 23:36, Ulf Samuelsson wrote:
> Den 2023-04-27 kl. 19:09, skrev Rick C:
>> On Thursday, April 27, 2023 at 12:26:47 PM UTC-4, Ulf Samuelsson wrote:
>>> Den 2023-04-20 kl. 04:06, skrev Rick C:
>>>> This is a bit of the chicken and egg thing. If you want a embed a
>>>> checksum in a code module to report the checksum, is there a way of
>>>> doing this? It's a bit like being your own grandfather, I think.
>>>>
>>> The proper way to do this is to have a directive in the linker.
>>> This reserves space for the CRC and defines the area where the CRC is
>>> calculated.
>>
>> That assumes there is a linker. How does the application access this
>> information?
>>
>>
> Linker command file
> public CRC64; start, stop
> HEADER = .;
> QUAD(MAGIC);
> CRC64 = .;
> DIGEST "CRC64-ECMA", (start, stop)
> start = .;
> # Your data to be protected
> ...
> stop = .;
>
> C source code.
>
> extern uint64_t CRC64;
> extern char* start;
> extern char* stop;
>
> uint64_t crc;
>
> crc64 = calc_crc64_ecma(start, stop);
> if (crc64 == CRC64) {
> /* everything is OK */
> }
I'm nit-picking, but that C code does not look right to me. The extern
declarations for "start" and "stop" claim them to be names of memory
locations that contain addresses, but the linker file just places them
at the starting and one-past-end locations of the block to be protected.
So the "start" variable contains the first bytes of the "data to be
protected", and the contents of the "stop" variable are not defined
because it is placed after the "data to be protected", where no code or
data is loaded (it seems).
It seems to me that the call to calc_crc64_ecma should get the addresses
of "start" and "stop" as arguments (&start, &stop), instead of their
values. But perhaps calc_crc64_ecma is not a function, but a macro that
can itself take the addresses of its parameters.
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Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-19 19:06 -0700
Re: Embedding a Checksum in an Image File Niklas Holsti <niklas.holsti@tidorum.invalid> - 2023-04-20 12:14 +0300
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-20 06:18 -0700
Re: Embedding a Checksum in an Image File "Peter Heitzer" <peter.heitzer@rz.uni-regensburg.de> - 2023-04-20 11:30 +0000
Re: Embedding a Checksum in an Image File dalai lamah <antonio12358@hotmail.com> - 2023-04-20 13:47 +0200
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-20 06:04 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-20 16:46 +0200
Re: Embedding a Checksum in an Image File George Neuner <gneuner2@comcast.net> - 2023-04-20 11:33 -0400
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-20 09:45 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-20 22:26 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-27 18:36 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 09:12 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-28 10:35 +0200
Re: Embedding a Checksum in an Image File George Neuner <gneuner2@comcast.net> - 2023-04-20 16:44 -0400
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-04-20 22:37 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-21 12:43 +0200
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-04-21 04:39 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-21 16:50 +0200
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-04-21 17:29 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-22 16:57 +0200
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-04-24 00:32 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-24 16:37 +0200
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-05-03 00:15 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-05-03 14:48 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-05-09 20:42 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-05-10 10:06 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-05-10 12:03 +0200
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-08-05 01:48 -0700
Re: Embedding a Checksum in an Image File Don Y <blockedofcourse@foo.invalid> - 2023-08-05 01:42 -0700
Re: Embedding a Checksum in an Image File Stefan Reuther <stefan.news@arcor.de> - 2023-04-21 19:40 +0200
Re: Embedding a Checksum in an Image File Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2023-04-20 20:17 +0300
Re: Embedding a Checksum in an Image File George Neuner <gneuner2@comcast.net> - 2023-04-20 16:49 -0400
Re: Embedding a Checksum in an Image File Richard Damon <Richard@Damon-Family.org> - 2023-04-20 22:09 -0400
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-20 19:41 -0700
Re: Embedding a Checksum in an Image File Richard Damon <Richard@Damon-Family.org> - 2023-04-21 19:30 -0400
Re: Embedding a Checksum in an Image File Brian Cockburn <brian.cockburn.1959@gmail.com> - 2023-04-21 01:53 -0700
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-21 05:12 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-21 17:02 +0200
Re: Embedding a Checksum in an Image File Brian Cockburn <brian.cockburn.1959@gmail.com> - 2023-04-21 16:56 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-22 17:01 +0200
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-21 20:14 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-22 17:13 +0200
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-22 09:56 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-22 19:54 +0200
Re: Embedding a Checksum in an Image File Grant Edwards <invalid@invalid.invalid> - 2023-04-22 20:05 +0000
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-23 17:37 +0200
Re: Embedding a Checksum in an Image File Grant Edwards <invalid@invalid.invalid> - 2023-04-23 17:37 +0000
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-23 23:45 +0200
Re: Embedding a Checksum in an Image File Richard Damon <Richard@Damon-Family.org> - 2023-04-23 18:16 -0400
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-24 09:13 +0200
Re: Embedding a Checksum in an Image File boB <boB@K7IQ.com> - 2023-04-22 13:41 -0700
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-23 10:34 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-23 23:58 +0200
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-23 15:24 -0700
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-24 09:17 +0200
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-24 01:07 -0700
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-27 18:42 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 09:20 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-28 10:44 +0200
Re: Embedding a Checksum in an Image File Brian Cockburn <brian.cockburn.1959@gmail.com> - 2023-04-21 16:52 -0700
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-21 20:23 -0700
Re: Embedding a Checksum in an Image File Brian Cockburn <brian.cockburn.1959@gmail.com> - 2023-04-22 07:07 -0700
Re: Embedding a Checksum in an Image File Richard Damon <Richard@Damon-Family.org> - 2023-04-22 10:31 -0400
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-22 09:54 -0700
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-27 18:26 +0200
Re: Embedding a Checksum in an Image File Rick C <gnuarm.deletethisbit@gmail.com> - 2023-04-27 10:09 -0700
Re: Embedding a Checksum in an Image File Niklas Holsti <niklas.holsti@tidorum.invalid> - 2023-04-27 21:29 +0300
Re: Embedding a Checksum in an Image File Niklas Holsti <niklas.holsti@tidorum.invalid> - 2023-04-27 21:39 +0300
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-27 22:44 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 09:38 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-28 10:50 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 15:04 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-29 23:03 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-30 16:19 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-05-09 20:34 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-05-10 10:18 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 09:33 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-27 22:36 +0200
Re: Embedding a Checksum in an Image File Niklas Holsti <niklas.holsti@tidorum.invalid> - 2023-04-28 01:10 +0300
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-28 10:54 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 09:24 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-28 10:56 +0200
Re: Embedding a Checksum in an Image File David Brown <david.brown@hesbynett.no> - 2023-04-28 15:09 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-29 23:02 +0200
Re: Embedding a Checksum in an Image File Ulf Samuelsson <ulf.r.samuelsson@gmail.com> - 2023-04-27 18:27 +0200
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