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>
diff --git a/cbtable.c b/cbtable.c
index 2611a62..c12354c 100644
--- a/cbtable.c
+++ b/cbtable.c
@@ -6,6 +6,7 @@
* (Written by Eric Biederman <ebiederman@lnxi.com> for Linux Networx)
* Copyright (C) 2006-2009 coresystems GmbH
* (Written by Stefan Reinauer <stepan@coresystems.de> for coresystems GmbH)
+ * Copyright (C) 2010 Carl-Daniel Hailfinger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -207,11 +208,15 @@
#else
start = 0x0;
#endif
- table_area = physmap("low megabyte", start, BYTES_TO_MAP);
+ table_area = physmap_try_ro("low megabyte", start, BYTES_TO_MAP - start);
+ if (!table_area) {
+ msg_perr("Failed getting access to coreboot low tables.\n");
+ return -1;
+ }
lb_table = find_lb_table(table_area, 0x00000, 0x1000);
if (!lb_table)
- lb_table = find_lb_table(table_area, 0xf0000, BYTES_TO_MAP);
+ lb_table = find_lb_table(table_area, 0xf0000 - start, BYTES_TO_MAP - start);
if (lb_table) {
struct lb_forward *forward = (struct lb_forward *)
(((char *)lb_table) + lb_table->header_bytes);
@@ -219,7 +224,12 @@
start = forward->forward;
start &= ~(getpagesize() - 1);
physunmap(table_area, BYTES_TO_MAP);
- table_area = physmap("high tables", start, BYTES_TO_MAP);
+ table_area = physmap_try_ro("high tables", start, BYTES_TO_MAP);
+ if (!table_area) {
+ msg_perr("Failed getting access to coreboot "
+ "high tables.\n");
+ return -1;
+ }
lb_table = find_lb_table(table_area, 0x00000, 0x1000);
}
}