Re: BSD_SYMTAB ELF notes

[Roger Pau Monné <roger.pau%citrix.com@localhost>]

On 07/08/14 23:48, Ryan O'Neill wrote:
> Hello. After reading through some of the libelf-loader.c and 
> libelf-dominfo.c code, it appears that Xen expects BSD guest
> kernels to have an ELF .note auxillary entry of type
> XEN_ELFNOTE_BSD_SYMTAB that gets parsed in so that Xen knows to
> allocate room for the kernels symbol table.

This is only used by PV(H) guests, this note is simply a boolean that
tells Xen whether to load the symtab and strtab or not. Linux for
example doesn't load the symtab and strtab, because it has no
in-kernel debugger and doesn't use the full symbol table.

> I do not see this Note (Or any note segment/section) in my freebsd
> guest kernel image (readelf -n). Can someone explain to me if this
> Note is still used? If so, then in what case?

You will see this note if you compile a i386 XEN kernel, or if you
compile a GENERIC amd64 kernel from -current.

Also, this is the netbsd-xen mailing list, I would recommend that you
use the freebsd-xen mailing list to ask questions about FreeBSD.

Roger.