Update rosetta.md

advanced/rosetta.md

@@ -48,3 +48,86 @@ The `magic` parameter describes the first 20 bytes of the ELF header for x86_64
 
 ## Installing Shared Libraries
 In order to run x86_64 executables, you still need to install shared libraries for x86_64. The instructions vary for different distros but usually involve enabling "multiarch" or "multilib" support.
+
+For example for distros using `apt` the package manager can be updated by adding the archiectrure to your source list `/etc/apt/sources.list`. For example on Debian:
+
+```
+deb [ arch=arm64,amd64 ] http://deb.debian.org/debian/ bookworm main contrib non-free-firmware non-free
+```
+and on Ubuntu:
+```
+Types: deb
+URIs: http://ports.ubuntu.com/ubuntu-ports/
+Suites: noble noble-updates noble-backports
+Components: main restricted universe multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
+Architectures: arm64
+
+Types: deb
+URIs: https://security.ports.ubuntu.com/ubuntu-ports/
+Suites: noble-security
+Components: main restricted universe multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
+Architectures: arm64
+
+Types: deb
+URIs: http://us.archive.ubuntu.com/ubuntu/
+Suites: noble noble-updates noble-backports
+Components: main restricted universe multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
+Architectures: amd64
+
+Types: deb
+URIs: http://security.ubuntu.com/ubuntu/
+Suites: noble-security
+Components: main restricted universe multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
+Architectures: amd64
+```
+## Configuring the Snap Store
+To use the Snap Store you need to register multiple CPU architectures with the kernal, add the `qemu-user` userspace emulator, and confirm `binfmt` integration so the kernal can transparently hand `amd64` binaries to the rosetta emulator. 
+```
+sudo apt install qemu-user-static binfmt-support
+sudo dpkg --add-architecture amd64
+sudo apt update
+```
+Now you are ready to install the amd64 install compilers
+```
+sudo apt install libc6:amd64 libstdc++6:amd64
+```
+Check if the `dpkg` command is setup to use amd64
+```
+dpkg --print-foreign-architectures
+```
+Now install `snapd` and refresh the Snap Store
+```
+sudo systemctl restart snapd
+sudo snap refresh
+```
+Snap is now installed and able to install both binaries targeting either ARM or x64 architectures. Snap will use ARM64 by default, unless AMD64 is specfied as follows:
+```
+UBUNTU_STORE_ARCH=amd64 snap download <snapname>
+```
+To verify the architecture of installed snaps:
+```
+snap list --all
+```
+
+> **⚠️ WARNING: Multi-Arch Hazard on Ubuntu**
+> 
+> Running `sudo dpkg --add-architecture amd64` on Ubuntu assumes that the update
+> binary URLs are identical across architectures. **They are not** — Ubuntu’s mirrors use architecture-specific paths.
+> If this command breaks apt, make sure architecture-specific repository lines exist for both the `arm64` and `amd64` sources.
+
+## Confirming Success
+
+To test if your system now has binaries avaliable via the package manager you can run the following command to check if both `arm64` and `amd64` are avaiable. For example the 7-zip program:
+```
+apt list p7zip-full
+```
+If you need to force install a program, you should also confirm it is an `ELF 64-bit LSB pie executable, x86-64` file.
+```
+sudo apt install p7zip-full:amd64
+file /usr/lib/p7zip/7z
+7z b
+```