Re: [Bug #11355] Regression in 2.6.27-rc2 when cross-building the kernel

David Woodhouse
2008-09-01T09:35:20Z

On Sun, 2008-08-24 at 23:34 +0200, Rafael J. Wysocki wrote:
> On Saturday, 23 of August 2008, Rafael J. Wysocki wrote:
> > This message has been generated automatically as a part of a report
> > of recent regressions.
> >
> > The following bug entry is on the current list of known regressions
> > from 2.6.26. Please verify if it still should be listed and let me know
> > (either way).
> >
> >
> > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=11355
> > Subject : Regression in 2.6.27-rc2 when cross-building the kernel
> > Submitter : Larry Finger <Larry.Finger-tQ5ms3gMjBLk1uMJSBkQmQ@public.gmane.org>
> > Date : 2008-08-16 2:38 (8 days old)
> > References : http://marc.info/?l=linux-kernel&m=121885432118368&w=4
>
> As I wrote in the Bugzilla, I'm seeing a related problem.
>
> Namely, I build kernels on one box, with 'make O=<target>', then I mount
> <target> on another one over NFS, 'cd' to it and try to install the kernel
> modules with 'make modules_install'. This results in 'HOSTCC firmware/ihex2fw'
> and 'fatal error: ...: Read-only file system'. It's readily reproducible.
>
> Commenting out line 1130 of Makefile
> ("$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modinst")
> obviously helps, so it looks like Makefile.fwinst needs fixing.

I don't like this much, but it should do the trick... please confirm.

diff --git a/firmware/Makefile b/firmware/Makefile
index aab12bf..e7130b5 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -166,15 +166,28 @@ $(patsubst %,$(obj)/%.gen.o, $(fw-external-y)): $(obj)/%.gen.o: $(fwdir)/%
$(obj)/%: $(obj)/%.ihex | $(objtree)/$(obj)/$$(dir %)
$(call cmd,ihex)

+# Don't depend on ihex2fw if we're installing and it already exists.
+# Putting it after | in the dependencies doesn't seem sufficient when
+# we're installing after a cross-compile, because ihex2fw has dependencies
+# on stuff like /usr/lib/gcc/ppc64-redhat-linux/4.3.0/include/stddef.h and
+# thus wants to be rebuilt. Which it can't be, if the prebuilt kernel tree
+# is exported read-only for someone to run 'make install'.
+ifeq ($(INSTALL):$(wildcard $(obj)/ihex2fw),install:$(obj)/ihex2fw)
+ihex2fw_dep :=
+else
+ihex2fw_dep := $(obj)/ihex2fw
+endif
+
+
# .HEX is also Intel HEX, but where the offset and length in each record
# is actually meaningful, because the firmware has to be loaded in a certain
# order rather than as a single binary blob. Thus, we convert them into our
# more compact binary representation of ihex records (<linux/ihex.h>)
-$(obj)/%.fw: $(obj)/%.HEX $(obj)/ihex2fw | $(objtree)/$(obj)/$$(dir %)
+$(obj)/%.fw: $(obj)/%.HEX $(ihex2fw_dep) | $(objtree)/$(obj)/$$(dir %)
$(call cmd,ihex2fw)

# .H16 is our own modified form of Intel HEX, with 16-bit length for records.
-$(obj)/%.fw: $(obj)/%.H16 $(obj)/ihex2fw | $(objtree)/$(obj)/$$(dir %)
+$(obj)/%.fw: $(obj)/%.H16 $(ihex2fw_dep) | $(objtree)/$(obj)/$$(dir %)
$(call cmd,h16tofw)

$(firmware-dirs):

--
dwmw2