mediatek/mt8183: Enable bootblock self-decompression

MT8183 only allows booting from eMMC, so we have to do eMMC emulation
from an external source, for example EC, which makes the size of
bootblock very important.

A fully functional bootblock (that can boot into verstage or romstage)
is about 38000 bytes. If self decompression (CONFIG_COMPRESS_BOOTBLOCK)
is enabled, only 25088 (66%) bytes are needed.

Inspired from crosreview.com/1070018.

BUG=b:80501386
TEST=manually flashed into kukui and boots into romstage.

Change-Id: I7a739866a4ea3bcafe2ff7b9e88d5ed00f3f3e40
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://review.coreboot.org/27599
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/soc/mediatek/mt8183/decompressor.c b/src/soc/mediatek/mt8183/decompressor.c
new file mode 100644
index 0000000000..d4a55b36c1
--- /dev/null
+++ b/src/soc/mediatek/mt8183/decompressor.c
@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <bootblock_common.h>
+#include <soc/mmu_operations.h>
+
+void decompressor_soc_init(void)
+{
+	mtk_mmu_init();
+}