Bootloader fails to load minimal kernel in release mode

[phil-opp]

Reported by Trinity on Twitter.

The failure message "Failed to load the kernel" comes from the bootloader in real mode, so it seems like the issue is only related to file size.

[lachlansneff]

This has been happening periodically to my os. As far as I can tell, it's dependent on file size, but not a maximum file size. Generally, if you remove a print or something along those lines, it'll work.

edit: It doesn't just happen in release mode.

[phil-opp]

@fdb-hiroshima @lachlansneff I fixed some alignment problems in rust-osdev/bootloader@2a36320, which solves the problem for me. Could you try if the newest bootloader version fixes it for you too? Just execute cargo clean, then the updated bootloader should be downloaded on the next build.