riscv: qemu: add SPL configuration

Add two new configurations (qemu-riscv{32,64}_spl_defconfig) with SPL
enabled for RISC-V QEMU. QEMU does not require SPL to run U-Boot. The
configurations are meant to help the development of SPL on RISC-V.

The configurations enable RAM as the only SPL boot device. Images must
be loaded at address 0x80200000. In the default boot flow, U-Boot SPL
starts in machine mode, loads the OpenSBI FW_DYNAMIC firmware and U-Boot
proper from the supplied FIT image, and starts OpenSBI. U-Boot proper is
then started in supervisor mode by OpenSBI.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
diff --git a/include/configs/qemu-riscv.h b/include/configs/qemu-riscv.h
index ecea1d4..fa9b9af 100644
--- a/include/configs/qemu-riscv.h
+++ b/include/configs/qemu-riscv.h
@@ -8,6 +8,18 @@
 
 #include <linux/sizes.h>
 
+#ifdef CONFIG_SPL
+
+#define CONFIG_SPL_MAX_SIZE		0x00100000
+#define CONFIG_SPL_BSS_START_ADDR	0x84000000
+#define CONFIG_SPL_BSS_MAX_SIZE		0x00100000
+#define CONFIG_SYS_SPL_MALLOC_START	0x84100000
+#define CONFIG_SYS_SPL_MALLOC_SIZE	0x00100000
+
+#define CONFIG_SPL_LOAD_FIT_ADDRESS	0x80200000
+
+#endif
+
 #define CONFIG_SYS_SDRAM_BASE		0x80000000
 #define CONFIG_SYS_INIT_SP_ADDR		(CONFIG_SYS_SDRAM_BASE + SZ_2M)
 
@@ -22,6 +34,7 @@
 /* Environment options */
 #define CONFIG_ENV_SIZE			SZ_128K
 
+#ifndef CONFIG_SPL_BUILD
 #define BOOT_TARGET_DEVICES(func) \
 	func(QEMU, qemu, na) \
 	func(VIRTIO, virtio, 0) \
@@ -47,5 +60,6 @@
 	"pxefile_addr_r=0x88200000\0" \
 	"ramdisk_addr_r=0x88300000\0" \
 	BOOTENV
+#endif
 
 #endif /* __CONFIG_H */