error compiling Multiboot 2 bootloader: expected relocatable

[xtex]

I am writing a bootloader with Multiboot2. I referenced the example code from the specification.

Code: Select all

multiboot_header: // Multiboot Header
    .long   MULTIBOOT2_HEADER_MAGIC
    .long   MULTIBOOT_ARCHITECTURE_I386
    .long   multiboot_header_end - multiboot_header
    .long   -(MULTIBOOT2_HEADER_MAGIC + MULTIBOOT_ARCHITECTURE_I386 + (multiboot_header_end - multiboot_header))

When I am trying to compile it with clang, a error happened on the last line: "error: expected relocatable expression"

Is there any way to solve it?

Thanks.

[Octocontrabass]

That error happens when Clang doesn't know the numeric value of one or more of the labels in that line. That can happen if you've made a mistake in copying the code, or if you're trying to assemble it without the C preprocessor.

Make sure your file has the correct extension. It must be ".S" or ".sx", not ".s".

[iansjack]

Have you defined multiboot_header_end somewhere in the code that you don't show?

[xtex]

Thanks everyone!