SUBDIRS= vs M=

Posted Jul 12, 2004 2:26 UTC (Mon) by kcannon (guest, #4867)
Parent article: Driver porting: compiling external modules

The 2.6.7 Makefiles say that an external module should be compiled by setting the variable M to the directory in which the module resides, rather than by setting SUBDIRS. The command line is

$ make -C /path/to/kernel/source M=/path/to/your/module modules

I've confirmed that this does work. What is the reason for choosing one over the other? Are they synonyms?

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SUBDIRS= vs M=

Posted Jul 12, 2004 13:54 UTC (Mon) by corbet (editor, #1) [Link] (1 responses)

You found the current way of doing things; the article is mildly out of date. I'll fix it, but, since the old scheme continues to work, it's not been my top priority...

SUBDIRS= vs M=

Posted Aug 26, 2004 17:10 UTC (Thu) by r2b2lewis (guest, #24285) [Link]

I am running on SuSE 9.1 (2.6.4-52-smp).

When I ran the make file using the line:

$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules

the make ran quickly without error.

However, when I changed that line to:

$(MAKE) -C $(KDIR) M=$(PWD) modules

I seem to be making the entire kernel again.

What's up with that?