[kvm-unit-tests PATCH v6 10/32] devicetree: Check that fdt is not NULL in dt_available()

[Nikos Nikoleris <nikos.nikoleris@arm.com>]

Up until now, for platforms that support DT, kvm-unit-tests would
unconditionally use DT to configure the system and the code made the
assumption that the fdt will always be a valid pointer.

On Arm systems that support both ACPI and DT, kvm-unit-tests plans to
follow the same convension as the Linux kernel: attempt to configure the
system using the DT first, then fallback to ACPI.

As a result, the fdt pointer can be NULL. Check for that in dt_available().

Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
[ Alex E: Minor changes to the commit message ]
---
 lib/devicetree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/devicetree.c b/lib/devicetree.c
index 78c1f6fb..3ff9d164 100644
--- a/lib/devicetree.c
+++ b/lib/devicetree.c
@@ -16,7 +16,7 @@ const void *dt_fdt(void)
 
 bool dt_available(void)
 {
-	return fdt_check_header(fdt) == 0;
+	return fdt && fdt_check_header(fdt) == 0;
 }
 
 int dt_get_nr_cells(int fdtnode, u32 *nr_address_cells, u32 *nr_size_cells)
-- 
2.25.1