Hacking When to use fusee-primary vs fusee-secondary

[jadog]

I have read the doc for Atmosphere to help me understand the purpose of fusee.

Spoiler: Atmosphere Doc Here

fusée
fusée is a custom bootloader used to start the Atmosphère environment. It is divided into three sub-components: fusée-primary, fusée-mtc and fusée-secondary.

fusée is also capable of chainloading other payloads (e.g.: Android).

fusée's behavior can be configured via the BCT.ini file located on the SD card.

fusée-primary
fusée-primary is the first piece of Atmosphère's code that runs on the hardware. It is distributed as a standalone payload designed to be launched via RCM by abusing the CVE-2018-6242 vulnerability.

This payload is responsible for all the low-level hardware initialization required by the Nintendo Switch, plus the extra task of initializing the SD card and reading the next fusée sub-components from it.

fusée-mtc
fusée-mtc is an optional, but heavily recommended sub-component that performs DRAM memory training. This ensures a proper environment for running the final fusée sub-component.

fusée-secondary
fusée-secondary is the last fusée sub-component that runs on the system. It is responsible for configuring and bootstrapping the Atmosphère environment by mimicking the Horizon OS's design. This includes setting up the cryptosystem, mounting or emulating the eMMC, injecting or patching system modules and launching the exosphère component.

However, there are still several things I'm unclear about. I figured out that to install games using Goldleaf, I must launch fusee-primary otherwise the patches that I installed from here don't appear to be used and I encounter errors (more on that below). More concerning however is that when I launch fusee primary and check under System, I don't see my firmware version like I do when using fusee-secondary to launch EmuMMC. When using fusee secondary, my firmware shows my version followed by 'E'. When using Fusee-primary, it just shows that a firmware update is available but doesn't show my firmware version.

So my question then is this. In what scenario is fusee-primary to be used and is it actually launching into EmuMMC? Also, is it possible to use fusee-secondary and install games via Goldleaf without encountering the error code 2002-4518 or the error code 2145-0001?

 

[BaamAlex]

You don't need fusee-secondary.bin for something. The primary loads the secondary. That's why it is in the atmosphere folder.

 

[Hayato213]

The patches you linked are for Fusee Primary, off course it ain't going to work without fusee primary.bin. If you want to to boot using fusee-secondary, you have to use Fss0 patches.

 

[jadog]

The patches you linked are for Fusee Primary, off course it ain't going to work without fusee primary.bin. If you want to to boot using fusee-secondary, you have to use Fss0 patches.

Can you explain this further? And what's the purpose of the secondary if it's not needed?

Also, how can I ensure I'm booting to EmuMMC with Fuse-primary?

 

[Hayato213]

Fusee-Secondary is the second stage of the loading CFW process, Fusee-Primary is your bootloader, official one for Atmosphere build.
There is a few ways you can load up atmosphere

Hekate-> Fusee-Primary-> Fusee-Secondary
Fusee-Primary-> Fusee-Secondary
Hekate-> Fusee-Secondary

https://gbatemp.net/threads/guide-to-choose-which-atmosphere-patches-to-use-on-switch-fw-10.563886/

 

[ZachyCatGames]

Fusee-Secondary is the second stage of the loading CFW process, Fusee-Primary is your bootloader, official one for Atmosphere build.
There is a few ways you can load up atmosphere

Hekate-> Fusee-Primary-> Fusee-Secondary
Fusee-Primary-> Fusee-Secondary
Hekate-> Fusee-Secondary

https://gbatemp.net/threads/guide-to-choose-which-atmosphere-patches-to-use-on-switch-fw-10.563886/

Fusee Secondary is over ever ran if you use fusee primary.
Hekate just grabs the kips and whatever from secondary (using information in fusee-secondary's header) and boots using them itself

With Fusee Primary:
Fusee Primary -> Fusee Secondary -> Sept Primary (if 7.0+) -> Sept Secondary (if 7.0+) -> Fusee Secondary (if 7.0+) -> normal HOS stuff

With Hekate:
Hekate -> Sept Primary (if 7.0+) -> Sept Secondary (if 7.0+) -> Hekate (if 7.0+) -> normal HOS stuff

 

[jadog]

Fusee Secondary is over ever ran if you use fusee primary.
Hekate just grabs the kips and whatever from secondary (using information in fusee-secondary's header) and boots using them itself

With Fusee Primary:
Fusee Primary -> Fusee Secondary -> Sept Primary (if 7.0+) -> Sept Secondary (if 7.0+) -> Fusee Secondary (if 7.0+) -> normal HOS stuff

With Hekate:
Hekate -> Sept Primary (if 7.0+) -> Sept Secondary (if 7.0+) -> Hekate (if 7.0+) -> normal HOS stuff

So then why am I unable to install games using the secondary with Goldleaf? Should I change the information in fusee-secondary's header?

 

[capsleepyy]

Fusee Secondary is over ever ran if you use fusee primary.
Hekate just grabs the kips and whatever from secondary (using information in fusee-secondary's header) and boots using them itself

With Fusee Primary:
Fusee Primary -> Fusee Secondary -> Sept Primary (if 7.0+) -> Sept Secondary (if 7.0+) -> Fusee Secondary (if 7.0+) -> normal HOS stuff

With Hekate:
Hekate -> Sept Primary (if 7.0+) -> Sept Secondary (if 7.0+) -> Hekate (if 7.0+) -> normal HOS stuff

Is Sept still needed when booting with Hekate? I can delete it off my SD and boot into FW 10.1.0 just fine

 

[ZachyCatGames]

So then why am I unable to install games using the secondary with Goldleaf? Should I change the information in fusee-secondary's header?

Dunno.
Unrelated

Is Sept still needed when booting with Hekate? I can delete it off my SD and boot into FW 10.1.0 just fine

Yes. Like the kips, exosphere, and all that stuff, sept can also be grabbed from fusee-secondary, which hekate does.

 

[Draxzelex]

So then why am I unable to install games using the secondary with Goldleaf? Should I change the information in fusee-secondary's header?

Probably because Goldleaf is arguably the worst title installer. Use something better such as Awoo Installer.