test/py: return a RAM address different from 0 as it can be interpreted as NULL

Some functions test that the given address is not NULL (0) and fail or
have a different behaviour if that's the case (e.g. hexport_r).

Let's make the RAM base address to be not zero by setting it to 2MiB if
that's the case.

2MiB is chosen because it represents the size of an ARM LPAE/v8 section.

Suggested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

test/py/u_boot_utils.py

@@ -236,6 +236,12 @@ def find_ram_base(u_boot_console):
             ram_base = -1
             raise Exception('Failed to find RAM bank start in `bdinfo`')
 
+    # We don't want ram_base to be zero as some functions test if the given
+    # address is NULL (0). Let's add 2MiB then (size of an ARM LPAE/v8 section).
+
+    if ram_base == 0:
+        ram_base += 1024 * 1024 * 2
+
     return ram_base
 
 class PersistentFileHelperCtxMgr(object):