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Groups > comp.arch.embedded > #31861
| From | Niklas Holsti <niklas.holsti@tidorum.invalid> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Embedding a Checksum in an Image File |
| Date | 2023-04-27 21:29 +0300 |
| Organization | Tidorum Ltd |
| Message-ID | <kavt7iFlvc5U1@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> |
On 2023-04-27 20:09, Rick C wrote:
> 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.
Almost all toolchains have a linker.
> How does the application access this information?
In Ulf's suggestion, it seems the DIGEST directive emits 8 bytes of
checksum at the current point (usually the linker "." symbol). I assume
one can give that point in the image a linkage symbol, perhaps like
_checksum DIGEST "CRC64-ECMA", (from, to)
or like
_checksum EQU. .
DIGEST "CRC64-ECMA", (from, to)
(This is schematic linker code, not necessarily proper syntax.)
One can then from the application code access the "checksum" location as
an externally defined object, say:
extern uint8[8] checksum;
The linker will connect that C identifier to the actual address of the
DIGEST checksum. Here I assumed that the C compiler mangles C
identifiers into linkage symbols by prefixing an underscore; YMMV.
> You are making a lot of assumptions about the tools. I'm pretty sure
> they don't apply to my case. I'm not at all clear how this is
> workable, anyway. Adding the checksum to the file, changes the
> checksum, which is where this conversation started... unless I'm
> missing something significant.
But you have insisted that your "checksum" is for the purpose of
identifying the version of the program, not for checking the integrity
of the memory image. If so, that checksum does not have to be the
checksum of the whole memory image, as long as it is the checksum of the
part of the image that contains the actual code and constant data, and
so will change according to changes in those parts of the image.
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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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