_extending_ platform support options?

Hi all,

currently I'm wondering what the preferred/recommend way of _extending_ an existing "Platform support" option is?

We are working with custom design/boards based on Virtex4/5. So we are primarily using the CONFIG_XILINX_VIRTEX*_GENERIC_BOARD options. In our case we have some special needs, like custom ppc_md.restart(), ppc_md.power_off() or ppc_md.show_cpuinfo().

Till now, we just duplicated arch/powerpc/platforms/4?x/virtex.c and added our special stuff. Properly renaming everything, etc ...

An alternative could be to add a virtex_my.c which extends virtex.c, like this (also like virtex_ml510.c extends virtex.c):

static void virtex_my_show_cpuinfo(struct seq_file *m)

{
	seq_printf(m, something);
}

static int __init virtex_mle_init(void)

{
	ppc_md.show_cpuinfo = virtex_my_show_cpuinfo;
	return 0;
}

machine_core_initcall(virtex, virtex_my_init);

Though, to me, it does not seem really OK to assign ppc_md members
that way. The original struct machdep for "virtex" (which is defined
in virtex.c with define_machine()) is not adjusted either. Ok, we
could modify that one, too.
Especially I'm not sure if it is OK to use machine_core_initcall() for such modifications.

So my question is: Is there any recommended way for doing such "extensions"? Or is it OK to just duplicate virtex.c (which does not seem really OK, too)?

Quoted 5 lines

Though, to me, it does not seem really OK to assign ppc_md members that way. The original struct machdep for "virtex" (which is defined in virtex.c with define_machine()) is not adjusted either. Ok, we could modify that one, too.
Especially I'm not sure if it is OK to use machine_core_initcall()

for such modifications.

Quoted 1 line

Quoted 3 lines

So my question is: Is there any recommended way for doing such "extensions"? Or is it OK to just duplicate virtex.c (which does not seem really OK, too)?

Duplicate it as you have done, naming the file something unique. We try
to prevent unnecessary duplication of code, but sometimes it's cleaner to just have a separate board file instead.