Add an option - AR71XX_REALMEM - which overrides the amount of

memory detected from Redboot, or overrides the "otherwise" case
if no Redboot information was found.

Some AR71XX platforms don't use Redboot (eg TP-LINK devices using
UBoot; some later Ubiquiti devices which apparently also use
UBoot) and at least one plain out lies - the Ubiquiti LS-SR71A
Redboot says there's 16mb of RAM when in fact there's 32mb.

A more "clean" solution will be needed at a later date.

2 files changed, 20 insertions, 0 deletions

diff --git a/sys/conf/options b/sys/conf/options
index a507d69..145b33b 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -872,3 +872,9 @@ SDP		opt_ofed.h
 SDP_DEBUG	opt_ofed.h
 IPOIB_DEBUG	opt_ofed.h
 IPOIB_CM	opt_ofed.h
+
+# At least one of the AR71XX ubiquiti boards has a Redboot configuration
+# that "lies" about the amount of RAM it has. Until a cleaner method is
+# defined, this option will suffice in overriding what Redboot says.
+AR71XX_REALMEM    opt_global.h
+
diff --git a/sys/mips/atheros/ar71xx_machdep.c b/sys/mips/atheros/ar71xx_machdep.c
index c8abc74..3d98cda 100644
--- a/sys/mips/atheros/ar71xx_machdep.c
+++ b/sys/mips/atheros/ar71xx_machdep.c
@@ -180,6 +180,20 @@ platform_start(__register_t a0 __unused, __register_t a1 __unused,
 	if (realmem == 0)
 		realmem = btoc(32*1024*1024);
 
+	/*
+	 * Allow build-time override in case Redboot lies
+	 * or in other situations (eg where there's u-boot)
+	 * where there isn't (yet) a convienent method of
+	 * being told how much RAM is available.
+	 *
+	 * This happens on at least the Ubiquiti LS-SR71A
+	 * board, where redboot says there's 16mb of RAM
+	 * but in fact there's 32mb.
+	 */
+#if	defined(AR71XX_REALMEM)
+		realmem = btoc(MIPS_REALMEM);
+#endif
+
 	/* phys_avail regions are in bytes */
 	phys_avail[0] = MIPS_KSEG0_TO_PHYS(kernel_kseg0_end);
 	phys_avail[1] = ctob(realmem);