Create a physical memory mapping function which requests cached readonly memory

This should take care of picky Linux kernels which do not allow uncached
mappings to cached areas. Handle mapping failure gracefully (no forced
exit()) if the caller specifies it.

Such cached areas which can handle mapping failure are DMI tables and
coreboot tables. On failure we just ignore those tables. That is not
perfect, but a lot better than aborting flashrom due to an error in
nonessential functionality.

This should fix flashrom on a sizable number of machines where it
currently aborts early.

Yes, I could have exploited a Linux kernel bug to "solve" this, but
relying on such bugs is not exactly the best idea.

Corresponding to flashrom svn r889.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Vincent Pelletier <plr.vincent@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/flash.h b/flash.h
index 3d31d44f..d8f02bbe 100644
--- a/flash.h
+++ b/flash.h
@@ -343,6 +343,7 @@ int chipset_flash_enable(void);
 
 /* physmap.c */
 void *physmap(const char *descr, unsigned long phys_addr, size_t len);
+void *physmap_try_ro(const char *descr, unsigned long phys_addr, size_t len);
 void physunmap(void *virt_addr, size_t len);
 int setup_cpu_msr(int cpu);
 void cleanup_cpu_msr(void);