sorry if these don't make sense. I added them.
1) 2)
If you have CBHC, and decide to install Haxchi direct (you know, the one without coldboot support and NO config.txt to recover into HBL) then YES, you will 100% brick.
replacing CBHC with anything which doesn't have a config.txt will brick.
it's always safer to uninstall CBHC before installing any "non coldboot" supported application. no? doesn't make sense?
I just wanted to prevent users from bricking (some already did !)
Your sys.xml file will already be there in the system nand from your old install.
Hmmm, there's no "system.xml" for haxchi, maybe you mistaken with "reinstalling CBHC over CBHC?" or haxchi over CBHC which is not recommended, as haxchi is not compatible with coldboot.
but installing Haxchi over CBHC+system.xml will not really use the "xml already there in system nand from your old install" as haxchi is not set to use an "old sys.xml from an old install" even if it's using the system.xml from cbhc. it's a partial coldboot.
What will happen is that system XML will tell the console to boot haxchi title.
if you set haxchi to patch your system menu (default=sysmenu) then it will reload system.xml which will again tell to load haxchi, etc. boot loop.
if you have default to HBL, then you are fine.
if you have default to "haxchi direct" : brick
default to "fw.img" on SD, hope that you have other button config to boot HBL, or an existing NAND dump and you'll need a partial redNAND (only redirecting NAND mlc, not slc, so you can restore the sysNAND's system.xml with wup server)
default to fw.img on NAND (there's a version to do that), it will depend what that fw.img is doing, it could be bad for you.
it all depends what you do with the loaded title in system.xml, there are a lot of possibilities, I just warned users to not mess with it, it's just safer to uninstall CBHC before not wanting it anymore.
3)
Haxchi can be moved to USB, but you can obviously launch it only when your USB is connected.
If I kept "don't install haxchi to USB" people would have argued that it's not true and it works fine from there.
You can copy over and install your vc titles to usb from main memory and it wont affect anything as long as you don't delete the original versions of your main memory. They are what matters as long as your vc titles stay on your system memory you will be fine no matter what you do!
Again, I think you are mixing CBHC and haxchi.
CBHC NEEEEED to stay on system memory, or you will brick.
but haxchi is just a homebrew inside a DS rom, you can launch it from anywhere manually.
it's only system.xml which can't launch a title located on USB. as long as you don't coldboot it you are fine.
of course, if you installed haxchi OVER cbhc, and it still has system.xml set to autoboot it, do not move it to USB!
You can "copy" it to USB if you want, as long as haxchi is on system NAND it's fine for coldboot/cbhc.
that's also why I suggested to put haxchi on System and original NDS game on USB, and not the contrary!
putting haxchi on USB while keeping the original game on USB is dangerous and stupid for coldboot installation.
3)
You can't have both NDS and haxchi ?
I thought USB had priority.
Why would it brick asap?
I have copied both vc titles over to usb hdd many times in rednand out of rednand and it still loads the system memory versions first on boot up
Again, I think you mix Haxchi and coldboot !
There's no "on boot up" with haxchi.
if you use coldboot, it will load the title located on NAND, not the one on USB.
also deleting them off usb does not make a difference either.
same here.
deleting the USB one, but keeping the sysNAND one doesn't make any difference, that's totally normal in case of coldboot. it's loading the one on sysNAND, CBHC doesn't look on USB.
If this was a fact and it loaded the usb versions first, it would brick asap.
Why would it brick by loading the USB first?
I'm talking about haxchi only, ok?
no coldboot option installed AT ALL.
if you plug your USB, the console sees and launch the game installed on USB. using the savegame and DLC located on USB too. there's no brick at launching an USB title manually.
Of course, installing CBHC, overwriting it with haxchi without uninstalling CBHC, and thinking "I have haxchi, not CBHC, so I can move haxchi to USB" you will brick !! because you didn't follow the FAQ telling you to uninstall haxchi first for safety.
So, I understand it was maybe unnecessary to add all these Q/A, but I wanted to list all possibilities, taking both haxchi and CBHC differences in account.
now, that's the issue, lot of users are mixing what they are reading and don't understand the tool's differences. that's what this FAQ should provide, a difference list and what's possible or not.
@C0mm4nd_
Q: Can I have my NDS game on both USB and System NAND?
A: Yes, but System NAND will have priority at Haxchi launch time.
I see you already replaced it, which is wrong.
Haxchi doesn't have sysNAND priority. haxchi doesn't really have priority, the console does.
When you launch a title, it has USB priority if you have the same title on both sysNAND and USB. when you launch haxchi (which the console sees as a NDS VC game) it will prioritize the USB.
Are you sure SysNAND has priority? I've read many times that the console prioritize USB.
this is why it was required to move the game data to USB before installing a game with WUP Installer to USB, or else the users will lose their savegame/Data/DLC/etc.
USB has priority.
Maybe we could just replace with something more generic and less dangerous, that'll be fine with me:
Q: Can I have my NDS game on both USB and System NAND?
A: Yes, but this is not recommended and can be problematic if you don't understand what you are doing. It's recommended to keep it on SysNAND only.
Q: So can I use this dual location to have haxchi and the original NDS game at the same time?
A: yes, but it's complicated and can cause issues. if you have to ask how to do it in this FAQ, you shouldn't do it.
Another Q/A to add:
Haxchi - Uninstallation
Q: How to uninstall Hachi?
A: You can delete the NDS game from the Wii U data management menu,
or re-install your original NDS game over haxchi. <-- add this?
CBHC Usage:
Q: Is there anything I shouldn't do while having CBHC installed?
A: DO NOT reinstall your original NDS VC game you used as host to install Haxchi/CBHC. it will replace CBHC and
will brick. (it will not even launch that game at boot)
Q: I don't see CBHC in the data management menu.
A: It's hidden for safety, so you can't delete it or move it to USB.