riscv: qemu: Enable Bochs video support

Enable video console using the emulated Bochs VGA card.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

board/emulation/qemu-riscv/Kconfig

@@ -68,5 +68,8 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	imply MTD_NOR_FLASH
 	imply CFI_FLASH
 	imply OF_HAS_PRIOR_STAGE
+	imply VIDEO
+	imply VIDEO_BOCHS
+	imply SYS_WHITE_ON_BLACK
 
 endif

doc/board/emulation/qemu-riscv.rst

@@ -133,6 +133,11 @@ An attached disk can be emulated in RISC-V virt machine by adding::
 
 You will have to run 'scsi scan' to use it.
 
+A video console can be emulated in RISC-V virt machine by removing "-nographic"
+and adding::
+
+    -serial stdio -device VGA
+
 Running with KVM
 ----------------
 

include/configs/qemu-riscv.h

@@ -17,6 +17,10 @@
 
 /* Environment options */
 
+#define CFG_STD_DEVICES_SETTINGS	"stdin=serial\0" \
+					"stdout=serial,vidconsole\0" \
+					"stderr=serial,vidconsole\0"
+
 #define BOOT_TARGET_DEVICES(func) \
 	func(QEMU, qemu, na) \
 	func(VIRTIO, virtio, 0) \
@@ -35,6 +39,7 @@
 	"qemu "
 
 #define CFG_EXTRA_ENV_SETTINGS \
+	CFG_STD_DEVICES_SETTINGS \
 	"fdt_high=0xffffffffffffffff\0" \
 	"initrd_high=0xffffffffffffffff\0" \
 	"kernel_addr_r=0x84000000\0" \