On Wed, Jul 23, 2014 at 9:45 AM, Ian Campbell <ian.campbell@citrix.com> wrote:
They might be in e.g. flash or something but more likely they could
bein a bank of RAM which we aren't handling or in RAM which the
bootloader hasn't told us about for some reason.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Fu Wei <fu.wei@linaro.org>
Cc: Roy Franz <roy.franz@linaro.org>
---
 xen/arch/arm/setup.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index e53e491..446b4dc 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -247,8 +247,13 @@ void __init discard_initial_modules(void)
         paddr_t s = mi->module[i].start;
         paddr_t e = s + PAGE_ALIGN(mi->module[i].size);

-        if ( mi->module[i].kind != BOOTMOD_XEN )
-            dt_unreserved_regions(s, e, init_domheap_pages, 0);
+        if ( mi->module[i].kind == BOOTMOD_XEN )
+            continue;
+
+        if ( !mfn_valid(paddr_to_pfn(s)) || !mfn_valid(paddr_to_pfn(e)))
+            continue;
+
+        dt_unreserved_regions(s, e, init_domheap_pages, 0);
     }

     mi->nr_mods = 0;

This looks good - I'll give it a spin.  I think this will be sufficient to allow the stub (or GRUB) to use any available EFI memory for loading modules
without worrying about whether XEN will map it.

Thanks,
Roy