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Mapping a file to memory

Discuss issues related to the Casio Prizm 3rd party development
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Re: Mapping a file to memory

Postby AmazoNKA » Sun Jun 05, 2016 6:55 pm

That's interesting.
I have a new fx-cg 20 which came with 2.02 out of the box. How could I check if the bootloader is different on it? Or is bootloader updated with os even on older calculators please? Is os checksum verified only at uploading of os from pc? Or/and at reboots as well? Or other times too? Also do you use fx-cg manager plus emulator ever?

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Re: Mapping a file to memory

Postby AmazoNKA » Sun Jun 05, 2016 10:29 pm

I also meant to ask if bootloader was ever involved in verifying OS checksums and if so how does bootloader know the changed of their addresses please. Thanks again

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Re: Mapping a file to memory

Postby SimonLothar » Mon Jun 06, 2016 9:23 pm

AmazoNKA wrote:How could I check if the bootloader is different on it?
Exact way: Compare the address range 80000000-8001FFFF. Less exact: Compare the checksum at 8001FFFC.
AmazoNKA wrote:Or is bootloader updated with os even on older calculators please?
Nope. The bootloader, t. i. the range 0x80000000-0x8001FFFF, is not touched during os update.
AmazoNKA wrote:Is os checksum verified only at uploading of os from pc or/and at reboots as well?
The os checksum is checked on restart (restart button, battery replacement, reboot after some bad error), provided that the corresponding parts of the os are still operative.
AmazoNKA wrote:Or other times too?
Not that I know of.
AmazoNKA wrote:Also do you use fx-cg manager plus emulator ever?
Nope.
AmazoNKA wrote:I also meant to ask if bootloader was ever involved in verifying OS checksums and if so how does bootloader know the changed of their addresses please.
The bootloader cannot verify the os checksum. It cannot know the algorithm. The bootloader verifies the string "CASIOWIN" at 0x80020000.
I'll be back!

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Re: Mapping a file to memory

Postby AmazoNKA » Mon Jun 06, 2016 10:40 pm

Thanks for that all, i will check what bootloaders i have just out of curiosity once I figured out the above.

Have you ever tried the emulator? Are you on Windows? I created scripts making testing add-ins quite quick - you probably use upload and run on real hardware but if you want me to share how i use the emulator on Windows please just let me know and i will be happy to.

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Re: Mapping a file to memory

Postby TeamFX » Tue Jun 07, 2016 11:25 pm

AmazoNKA wrote:I have a new fx-cg 20 which came with 2.02 out of the box. How could I check if the bootloader is different on it?

You can check the date with [OPTN]+[EXP]+[AC/ON] followed by [F1], [9] and [4].
"DateA" is the boot code date and "DateO" the OS date.
You can dump this boot code using Simon's add-in: https://www.cemetech.net/forum/viewtopi ... 673#210673
Creating the file M1.BKP is sufficient.
You may send this to my email address teamfx.casio@gmail.com

If the OS 2.02 setup is right, you should have a newer boot code but date and checksum might be slightly different.
fx-CG10/20 and fx-CG20 AU with OS 2.01 still have the old boot code 2010.0910.1621
Last edited by TeamFX on Wed Jun 08, 2016 10:57 am, edited 1 time in total.

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Re: Mapping a file to memory

Postby AmazoNKA » Wed Jun 08, 2016 9:57 am

Thanks for that guidance.
The key combo gave me the following info:
Os ver 02.02.0201
DateO 2015.1127.1657
DateA 2015.1116.2146

i will upload the dump once i'm at a computor and have Simon's tool installed

Many thanks again

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Re: Mapping a file to memory

Postby TeamFX » Wed Jun 08, 2016 10:45 am

Are you sure the OS version is correct? It should be 02.02.0200

Otherwise, we may have a hardware change here.
The OS date is identical to the official version, but some bytes in the area 0x80B20000..0x80B60000 are not covered by the OS checksum and might be different on your calculator. Please create the file M6.BKP as well.
Thanks.

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Re: Mapping a file to memory

Postby AmazoNKA » Wed Jun 08, 2016 1:53 pm

Yes, I double checked. It is fx-cg 20 taken out of sealed United Kingdom packaging stating it is good for A-levels etc. Maybe it is regional variation?

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Re: Mapping a file to memory

Postby TeamFX » Wed Jun 08, 2016 3:17 pm

Oh, so it is really displaying 02.02.0201 and not 02.02.0200?

That is strange. Usually, the extra "1" is a compilation flag meaning there would be two releases of the same base OS version.
Only Prizm OS 1.04 used this flag. The old version had date 2012.0305.1800 and the new one 2012.1009.1425 which was preinstalled on Prizms with Macronix hardware.

Yet, we see that both OS 2.02 dates are the same...

There are two scenarios to solve this:
1) Casio changed the OS version display routine depending on the model/hardware type.
2) Both OSes have been compiled on 2015-11-27 16:57, but the checksums are different.

I guess, it would be best to make a complete OS dump now:
https://www.cemetech.net/forum/viewtopi ... 673#210673

Does this calculator have an exam mode LED next to the 3-pin port?
Similar to this: https://tiplanet.org/forum/gallery/imag ... w=no_count

What is the diagnostic mode (OPTN+EXP+AC/ON) displaying in the first line?
Something like: [LY755EZ MAIN] 000

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Re: Mapping a file to memory

Postby AmazoNKA » Wed Jun 08, 2016 4:43 pm

I'm not in front of it yet to check but doubt there is any led there, will check but don't remember any difference. I think packaging mentioned exam mode but I assume they meant new os, not hardware. All I remember the battery cover was a bit more wobbly and specs print on the back slightly changed. Plastic felt a touch velvety but maybe it was just newer but I doubt it because i had a touch of new old models from the box recently too.

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