dm: Allow serial output during the relocation process

Reset the serial flags so that the debug UART can be used (if enabled)
in the small window where there is no serial device. This can avoid a hang
in some cases.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/common/board_r.c b/common/board_r.c
index c6c0c1a..e450033 100644 (file)
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -797,6 +797,15 @@ static init_fnc_t init_sequence_r[] = {
 void board_init_r(gd_t *new_gd, ulong dest_addr)
 {
        /*
+        * The pre-relocation drivers may be using memory that has now gone
+        * away. Mark serial as unavailable - this will fall back to the debug
+        * UART if available.
+        *
+        * Do the same with log drivers since the memory may not be available.
+        */
+       gd->flags &= ~(GD_FLG_SERIAL_READY | GD_FLG_LOG_READY);
+
+       /*
         * Set up the new global data pointer. So far only x86 does this
         * here.
         * TODO(sjg@chromium.org): Consider doing this for all archs, or