(Phat XDKs Only) What does a dev kit have that a test kit doesn't that enables kernel debugging?

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AS918

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Title. I know hardware wise, tests and devs are basically identical, apart from case color and all. Bootrom is the same across all 360 models regardless of type. Software wise, how can the 360 distinguish a test kit from a dev, given that the hardware is identical mostly? Is there a way to enable kernel debugging on a test kit (I don't need it at boot, I just need kernel debugging when the system is running and dashboard is loaded)
 
From what I can remember, XBDM is different, the kernel is also different and finally there is a devkit/testkit flag in the keyvault if I am not mistaken.

On Slim they only detect sidecar vs no sidecar and internal vs external (through the recint.ini file on flash) as kernel, xbdm and keyvault are identical on slim.
 
I see. Is there any way to modify a test kit to enable kernel debugging? I have a dev kit NAND (I no longer have that dev kit itself, but I still got the NAND dump and the CPU Key along with the other important files from that dev kit) so is it possible to do a KV transplant or a XBDM/Kernel transplant? @Mathieulh
 
I heard there is a xex that does the conversion for you but I never got my hands on that.
Otherwise the right way would be to transplant a kv, kernel and flash from a devkit to a testkit to convert it. KV are signed, I am not sure if the private key for dev kvs are out there (probably not).

Assuming the fuseline between devkit and testkit are identical though.
 
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Mathieulh said:
I heard there is a xex that does the conversion for you but I never got my hands on that.
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As far as I know, that XEX only changed the xshell text to say "Development Kit" instead of "Test Kit". I don't think it actually enabled kernel debugging.
 
Alpha said:
As far as I know, that XEX only changed the xshell text to say "Development Kit" instead of "Test Kit". I don't think it actually enabled kernel debugging.
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Oh! Ok, kinda useless then I guess. That said, swapping a keyvault + kernel or writing a devkit kernel, corrupting the kv and running a recovery disc, would do the trick.

UPDATE: I looked further into it, the second fuse row differs between devkit and testkit so devkit kernels will not run as is on a testkit, you therefore need to patch the kernel (using a hv payload) to disable signature checks on shadowboot kernels on testkits and load a devkit kernel. It wouldn't be a true conversion however as that is actually impossible.

All Slim units however, even those that report as testkits are actually all devkits, there is a check for sidecar connectivity in xbdm.xex which disables debug features if present, that check is skipped if recint.init is found with the internal xbdm drivemap setting enabled.

You can also patch xbdm directly to always skip the check. (This does NOT work on fat/real testkits)
 
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The test kit only have one port on the sidecar but the dev kit has too. The port is still there but covered up under plastic.
 
Edward_2452 said:
The test kit only have one port on the sidecar but the dev kit has too. The port is still there but covered up under plastic.
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The number of USB ports on your sidecar (or the type of sidecar you've got) is totally irrelevant to whether or not you own a devkit vs testkit, the old kit sidecars used to have a PIX USB port (which was not functional on testkit as it wasn't supported at the kernel level, although you could still plug it in), which has later been deprecated in devkits and testkit alike because the PIX functionality has been build into the kernel (to be specific it is now part of kdnet).

Because developers no longer needed to use the aforementioned PIX port, but Microsoft had yet to renew their sidecar parts, they eventually shipped the old sidecars with PIX hardware but a custom plastic shell that covered the port, eventually they switched to a new sidecar that did not include the PIX hardware at all, sidecars ever since the Zephyr era were used for DVD emulation exclusively, I believe the PIX hardware was removed from the sidecar by the time Jasper/XNA XDKs shipped.

This means you can have testkits and devkits tha have no PIX port (or at least none that's accessible out of the box) as well as testkits and devkits (usually xenon) which do have the PIX port available for use, obviously the is no point in having the PIX functionality on a sidecar unless you are using very old recoveries and XDK software, it's nice to have as a collectible I suppose, but adds nothing functionality wise since it is entirely defunct and deprecated.
 
By xex that converts kits did you guys mean this?



if yes then it also swaps the xbdm with the one included afaik.
 
weird, my slim test kit comes with sidecar installed but shows test kit on the dash, maybe the sidecar is faulty?
 
AS918 said:
Title. I know hardware wise, tests and devs are basically identical, apart from case color and all. Bootrom is the same across all 360 models regardless of type. Software wise, how can the 360 distinguish a test kit from a dev, given that the hardware is identical mostly? Is there a way to enable kernel debugging on a test kit (I don't need it at boot, I just need kernel debugging when the system is running and dashboard is loaded)
Click to expand...
XDK's have kernel debugging capabilities, if you want a more in-depth explanation; they have a couple of flags in their bootloaders that say that they're test kits, the signing key for the 3rd and 4th bootloaders are different from devkits, and the kernel is quite a bit different in the 5th bootloader.

I've written lots of code around converting test kits to devkits and it's a huge chore but it's definitely possible.
 
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