board: Add new Samsung "stemmy" board based on ST-Ericsson U8500
The ST-Ericsson U8500 SoC has been used in mass-production for
some Android smartphones released around 2012.
In particular, Samsung has released more than 5 different
smartphones based on U8500, e.g.
- Samsung Galaxy S III mini (GT-I8190) "golden"
- Samsung Galaxy S Advance (GT-I9070) "janice"
- Samsung Galaxy Xcover 2 (GT-S7710) "skomer"
and a few others.
Mainline Linux has great support for the Ux500 SoC, so these
smartphones can also run Linux mainline quite well.
Unfortunately, the original Samsung bootloader used on these devices
has limitations that prevent booting Linux mainline directly.
It keeps the L2 cache enabled, which causes Linux to crash very early,
shortly after decompressing the kernel.
Using U-Boot allows to circumvent these limitations. We can let the
Samsung bootloader chain-load U-Boot and U-Boot locks the L2 cache
before booting into Linux. U-Boot has several other advantages
- it supports device-trees directly and we are no longer limited to
flashing Android boot images through Samsung's proprietary download
mode.
The Samsung "stemmy" board covers all Samsung devices based on U8500.
Add minimal support for "stemmy". For now only UART is supported but
this will be extended later.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/configs/stemmy.h b/include/configs/stemmy.h
new file mode 100644
index 0000000..922eec4
--- /dev/null
+++ b/include/configs/stemmy.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019 Stephan Gerhold <stephan@gerhold.net>
+ */
+#ifndef __CONFIGS_STEMMY_H
+#define __CONFIGS_STEMMY_H
+
+#include <linux/sizes.h>
+
+#define CONFIG_SKIP_LOWLEVEL_INIT /* Loaded by another bootloader */
+#define CONFIG_SYS_MALLOC_LEN SZ_2M
+
+/* Physical Memory Map */
+#define PHYS_SDRAM_1 0x00000000 /* DDR-SDRAM Bank #1 */
+#define CONFIG_SYS_SDRAM_BASE PHYS_SDRAM_1
+#define CONFIG_SYS_SDRAM_SIZE SZ_1G
+#define CONFIG_SYS_INIT_RAM_SIZE 0x00100000
+#define CONFIG_SYS_GBL_DATA_OFFSET (CONFIG_SYS_SDRAM_BASE + \
+ CONFIG_SYS_INIT_RAM_SIZE - \
+ GENERATED_GBL_DATA_SIZE)
+#define CONFIG_SYS_INIT_SP_ADDR CONFIG_SYS_GBL_DATA_OFFSET
+
+/* FIXME: This should be loaded from device tree... */
+#define CONFIG_SYS_L2_PL310
+#define CONFIG_SYS_PL310_BASE 0xa0412000
+
+#define CONFIG_SYS_LOAD_ADDR 0x00100000
+
+#endif