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/bochs.c b/drivers/video/bochs.c
new file mode 100644
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);