riscv: ax25-ae350: add SPL configuration

This patch provides four configurations which can support U-Boot SPL
to boot from RAM or FLASH and then boot FIT image including OpenSBI
FW_DYNAMIC firmware and U-Boot proper images from RAM or MMC boot devices.

With ae350_rv[32|64]_spl_defconfigs:

U-Boot SPL will be loaded by gdb or FSBL and runs in RAM in machine mode
and then load FIT image from RAM device on AE350.

With ae350_rv[32|64]_spl_xip_defconfigs:

U-Boot SPL can be burned into SPI flash and run in flash in machine mode
and then load FIT image from SPI flash or MMC device on AE350.

Signed-off-by: Rick Chen <rick@andestech.com>
Cc: KC Lin <kclin@andestech.com>
Cc: Alan Kao <alankao@andestech.com>
diff --git a/board/AndesTech/ax25-ae350/Kconfig b/board/AndesTech/ax25-ae350/Kconfig
index 5e682b6..321dd0c 100644
--- a/board/AndesTech/ax25-ae350/Kconfig
+++ b/board/AndesTech/ax25-ae350/Kconfig
@@ -21,9 +21,18 @@
 config ENV_OFFSET
 	default 0x140000 if ENV_IS_IN_SPI_FLASH
 
+config SPL_TEXT_BASE
+	default 0x800000
+
+config SPL_OPENSBI_LOAD_ADDR
+	default 0x01000000
+
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select RISCV_NDS
+	select SUPPORT_SPL
 	imply SMP
+	imply SPL_RAM_SUPPORT
+	imply SPL_RAM_DEVICE
 
 endif
diff --git a/board/AndesTech/ax25-ae350/MAINTAINERS b/board/AndesTech/ax25-ae350/MAINTAINERS
index feed5d1..eebee16 100644
--- a/board/AndesTech/ax25-ae350/MAINTAINERS
+++ b/board/AndesTech/ax25-ae350/MAINTAINERS
@@ -7,3 +7,7 @@
 F:	configs/ae350_rv64_defconfig
 F:	configs/ae350_rv32_xip_defconfig
 F:	configs/ae350_rv64_xip_defconfig
+F:	configs/ae350_rv32_spl_defconfig
+F:	configs/ae350_rv64_spl_defconfig
+F:	configs/ae350_rv32_spl_xip_defconfig
+F:	configs/ae350_rv64_spl_xip_defconfig
diff --git a/board/AndesTech/ax25-ae350/ax25-ae350.c b/board/AndesTech/ax25-ae350/ax25-ae350.c
index b43eebb..b0164a9 100644
--- a/board/AndesTech/ax25-ae350/ax25-ae350.c
+++ b/board/AndesTech/ax25-ae350/ax25-ae350.c
@@ -12,6 +12,7 @@
 #include <faraday/ftsmc020.h>
 #include <fdtdec.h>
 #include <dm.h>
+#include <spl.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -110,3 +111,29 @@
 	return 0;
 }
 #endif
+
+#ifdef CONFIG_SPL
+void board_boot_order(u32 *spl_boot_list)
+{
+	u8 i;
+	u32 boot_devices[] = {
+#ifdef CONFIG_SPL_RAM_SUPPORT
+		BOOT_DEVICE_RAM,
+#endif
+#ifdef CONFIG_SPL_MMC_SUPPORT
+		BOOT_DEVICE_MMC1,
+#endif
+	};
+
+	for (i = 0; i < ARRAY_SIZE(boot_devices); i++)
+		spl_boot_list[i] = boot_devices[i];
+}
+#endif
+
+#ifdef CONFIG_SPL_LOAD_FIT
+int board_fit_config_name_match(const char *name)
+{
+	/* boot using first FIT config */
+	return 0;
+}
+#endif