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>

src/mainboard/google/kukui/Makefile.inc

@@ -1,4 +1,5 @@
 bootblock-y += memlayout.ld
+decompressor-y += memlayout.ld
 
 verstage-y += chromeos.c
 verstage-y += memlayout.ld

src/soc/mediatek/mt8183/Kconfig

@@ -10,6 +10,7 @@ config SOC_MEDIATEK_MT8183
 	select GENERIC_UDELAY
 	select HAVE_UART_SPECIAL
 	select HAVE_MONOTONIC_TIMER
+	select COMPRESS_BOOTBLOCK
 
 if SOC_MEDIATEK_MT8183
 

src/soc/mediatek/mt8183/Makefile.inc

@@ -11,6 +11,10 @@ bootblock-$(CONFIG_DRIVERS_UART) += ../common/uart.c
 endif
 bootblock-y += ../common/wdt.c
 
+decompressor-y += decompressor.c
+decompressor-y += ../common/mmu_operations.c
+decompressor-y += ../common/timer.c
+
 verstage-y += ../common/gpio.c gpio.c
 verstage-$(CONFIG_SPI_FLASH) += spi.c
 verstage-y += ../common/timer.c

src/soc/mediatek/mt8183/bootblock.c

@@ -20,7 +20,6 @@
 
 void bootblock_soc_init(void)
 {
-	mtk_mmu_init();
 	mt_pll_init();
 	mtk_wdt_init();
 }

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();
+}

src/soc/mediatek/mt8183/include/soc/memlayout.ld

@@ -39,9 +39,9 @@ SECTIONS
 	SRAM_END(0x00120000)
 
 	SRAM_L2C_START(0x00200000)
-	BOOTBLOCK(0x00201000, 85K)
-	VERSTAGE(0x00217000, 114K)
-	ROMSTAGE(0x00233800, 92K)
+	OVERLAP_DECOMPRESSOR_ROMSTAGE(0x000201000, 92K)
+	BOOTBLOCK(0x00227000, 89K)
+	VERSTAGE(0x0023E000, 114K)
 	SRAM_L2C_END(0x00280000)
 
 	DRAM_START(0x40000000)