On 12/14/25 12:54 AM, Rudraksha Gupta wrote:
Hello all,
I have the following problem: https://gitlab.postmarketos.org/postmarketOS/pmbootstrap/-/issues/2635
In short, what is happening is the following:
- The kernel boots and outputs via UART when I build the kernel with the following:
make LLVM=1 ARCH="$arm" CC="${CC:-gcc}"
- The kernel doesn't boot and there is no output via UART when I build the kernel with the following:
make LLVM=1 ARCH="$arm"
The only difference being: CC="${CC:-gcc}". Is this expected? I think this was present in the Linux kernel ever since Rust was enabled for ARMv7, and I never encountered it because postmarketOS was originally building the first way.
I've managed to the get the build setup for qemu-armv7. For some reason I could not get past the initrd even on kernels that are supposed to work, but I think that is unrelated (and not a kernel issue). On the linux-next kernel I didn't get any output on the console from qemu so I think I've reproduced the issue. Changing CONFIG_RUST=n did not change the behavior.
So I this is almost certainly a LLVM/clang issue and not a Rust issue. I'll try to do a bit more digging, but I'm not sure how much I'll get done.
Adding the LLVM and ARM lists to this conversation.
Cheers, Christian