x86: video: Add a driver for QEMU bochs emulation

Bochs is convenient with QEMU on x86 since it does not require a video
BIOS. Add a driver for it.

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

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 49762950719ebd78e20ddffff6a685ba4eb10624..2ba4f5eac7f3163b76a8f0493e6625b220ed8eab 100644 (file)
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -278,6 +278,36 @@ config VIDCONSOLE_AS_NAME
          possible to update the environment, the breakage may be confusing for
          users. This option will be removed around the end of 2020.
 
+config VIDEO_BOCHS
+       bool "Enable Bochs video emulation for QEMU"
+       depends on X86
+       help
+         Enable this to use the Bochs video support provided in the QEMU
+         emulator. This appears as a PCI device which U-Boot can set up to
+         provide a frame buffer.
+
+if VIDEO_BOCHS
+
+config VIDEO_BOCHS_SIZE_X
+       int "Width of display (X resolution)"
+       default 1280
+       help
+         Sets the width of the display.
+
+         These two options control the size of the display set up by QEMU.
+         Typical sizes are 1024 x 768 or 1280 x 1024.
+
+config VIDEO_BOCHS_SIZE_Y
+       int "High of display (Y resolution)"
+       default 1024
+       help
+         Sets the height of the display.
+
+         These two options control the size of the display set up by QEMU.
+         Typical sizes are 1024 x 768 or 1280 x 1024.
+
+endif
+
 config VIDEO_COREBOOT
        bool "Enable coreboot framebuffer driver support"
        depends on X86

diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index f99d7e3c3d9087ee2c17c47124567d2ca3a86506..a9263709084d5bb2af658d4c906578c88d9332e1 100644 (file)
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_OSD) += video_osd-uclass.o
 obj-$(CONFIG_SANDBOX_OSD) += sandbox_osd.o
 obj-$(CONFIG_VIDEO_ARM_MALIDP) += mali_dp.o
 obj-$(CONFIG_VIDEO_BCM2835) += bcm2835.o
+obj-$(CONFIG_VIDEO_BOCHS) += bochs.o
 obj-$(CONFIG_VIDEO_BROADWELL_IGD) += broadwell_igd.o
 obj-$(CONFIG_VIDEO_COREBOOT) += coreboot.o
 obj-$(CONFIG_VIDEO_DW_HDMI) += dw_hdmi.o

diff --git a/drivers/video/bochs.c b/drivers/video/bochs.c
new file mode 100644 (file)
index 0000000..2136b51
--- /dev/null
+++ b/drivers/video/bochs.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Modified from coreboot bochs.c
+ */
+
+#define LOG_CATEGORY   UCLASS_VIDEO
+
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <pci.h>
+#include <video.h>
+#include <asm/io.h>
+#include <asm/mtrr.h>
+#include <linux/sizes.h>
+#include "bochs.h"
+
+static int xsize = CONFIG_VIDEO_BOCHS_SIZE_X;
+static int ysize = CONFIG_VIDEO_BOCHS_SIZE_Y;
+
+static void bochs_write(void *mmio, int index, int val)
+{
+       writew(val, mmio + MMIO_BASE + index * 2);
+}
+
+static int bochs_read(void *mmio, int index)
+{
+       return readw(mmio + MMIO_BASE + index * 2);
+}
+
+static void bochs_vga_write(int index, uint8_t val)
+{
+       outb(val, VGA_INDEX);
+}
+
+static int bochs_init_fb(struct udevice *dev)
+{
+       struct video_uc_plat *plat = dev_get_uclass_plat(dev);
+       struct video_priv *uc_priv = dev_get_uclass_priv(dev);
+       ulong fb;
+       void *mmio;
+       int id, mem;
+
+       log_debug("probing %s at PCI %x\n", dev->name, dm_pci_get_bdf(dev));
+       fb = dm_pci_read_bar32(dev, 0);
+       if (!fb)
+               return log_msg_ret("fb", -EIO);
+
+       /* MMIO bar supported since qemu 3.0+ */
+       mmio = dm_pci_map_bar(dev, PCI_BASE_ADDRESS_2, 0, 0, PCI_REGION_TYPE,
+                             PCI_REGION_MEM);
+
+       if (!mmio)
+               return log_msg_ret("map", -EIO);
+
+       /* bochs dispi detection */
+       id = bochs_read(mmio, INDEX_ID);
+       if ((id & 0xfff0) != ID0) {
+               log_debug("ID mismatch\n");
+               return -EPROTONOSUPPORT;
+       }
+       mem = bochs_read(mmio, INDEX_VIDEO_MEMORY_64K) * SZ_64K;
+       log_debug("QEMU VGA: bochs @ %p: %d MiB FB at %lx\n", mmio, mem / SZ_1M,
+                 fb);
+
+       uc_priv->xsize = xsize;
+       uc_priv->ysize = ysize;
+       uc_priv->bpix = VIDEO_BPP32;
+
+       /* setup video mode */
+       bochs_write(mmio, INDEX_ENABLE,  0);
+       bochs_write(mmio, INDEX_BANK,  0);
+       bochs_write(mmio, INDEX_BPP, VNBITS(uc_priv->bpix));
+       bochs_write(mmio, INDEX_XRES, xsize);
+       bochs_write(mmio, INDEX_YRES, ysize);
+       bochs_write(mmio, INDEX_VIRT_WIDTH, xsize);
+       bochs_write(mmio, INDEX_VIRT_HEIGHT, ysize);
+       bochs_write(mmio, INDEX_X_OFFSET, 0);
+       bochs_write(mmio, INDEX_Y_OFFSET, 0);
+       bochs_write(mmio, INDEX_ENABLE, ENABLED | LFB_ENABLED);
+
+       bochs_vga_write(0, 0x20);       /* disable blanking */
+
+       plat->base = fb;
+
+       return 0;
+}
+
+static int bochs_video_probe(struct udevice *dev)
+{
+       int ret;
+
+       ret = bochs_init_fb(dev);
+       if (ret)
+               return log_ret(ret);
+
+       return 0;
+}
+
+static int bochs_video_bind(struct udevice *dev)
+{
+       struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
+
+       /* Set the maximum supported resolution */
+       uc_plat->size = 2560 * 1600 * 4;
+       log_debug("%s: Frame buffer size %x\n", __func__, uc_plat->size);
+
+       return 0;
+}
+
+U_BOOT_DRIVER(bochs_video) = {
+       .name   = "bochs_video",
+       .id     = UCLASS_VIDEO,
+       .bind   = bochs_video_bind,
+       .probe  = bochs_video_probe,
+};
+
+static struct pci_device_id bochs_video_supported[] = {
+       { PCI_DEVICE(0x1234, 0x1111) },
+       { },
+};
+
+U_BOOT_PCI_DEVICE(bochs_video, bochs_video_supported);

diff --git a/drivers/video/bochs.h b/drivers/video/bochs.h
new file mode 100644 (file)
index 0000000..4c8ec83
--- /dev/null
+++ b/drivers/video/bochs.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Modified from coreboot bochs.c
+ */
+
+#ifndef __BOCHS_H
+#define __BOCHS_H
+
+#define VGA_INDEX      0x3c0
+
+#define IOPORT_INDEX   0x01ce
+#define IOPORT_DATA    0x01cf
+
+enum {
+       INDEX_ID,
+       INDEX_XRES,
+       INDEX_YRES,
+       INDEX_BPP,
+       INDEX_ENABLE,
+       INDEX_BANK,
+       INDEX_VIRT_WIDTH,
+       INDEX_VIRT_HEIGHT,
+       INDEX_X_OFFSET,
+       INDEX_Y_OFFSET,
+       INDEX_VIDEO_MEMORY_64K
+};
+
+#define ID0            0xb0c0
+
+#define ENABLED                BIT(0)
+#define LFB_ENABLED    BIT(6)
+#define NOCLEARMEM     BIT(7)
+
+#define MMIO_BASE      0x500
+
+#endif