1 files changed, 135 insertions, 0 deletions
diff --git a/hw/display/ramfb.c b/hw/display/ramfb.c
new file mode 100644
index 00000000..79b9754a
--- /dev/null
+++ b/hw/display/ramfb.c
@@ -0,0 +1,135 @@
+/*
+ * early boot framebuffer in guest ram
+ * configured using fw_cfg
+ *
+ * Copyright Red Hat, Inc. 2017
+ *
+ * Author:
+ *     Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/loader.h"
+#include "hw/display/ramfb.h"
+#include "hw/display/bochs-vbe.h" /* for limits */
+#include "ui/console.h"
+#include "sysemu/reset.h"
+
+struct QEMU_PACKED RAMFBCfg {
+    uint64_t addr;
+    uint32_t fourcc;
+    uint32_t flags;
+    uint32_t width;
+    uint32_t height;
+    uint32_t stride;
+};
+
+struct RAMFBState {
+    DisplaySurface *ds;
+    uint32_t width, height;
+    struct RAMFBCfg cfg;
+};
+
+static void ramfb_unmap_display_surface(pixman_image_t *image, void *unused)
+{
+    void *data = pixman_image_get_data(image);
+    uint32_t size = pixman_image_get_stride(image) *
+        pixman_image_get_height(image);
+    cpu_physical_memory_unmap(data, size, 0, 0);
+}
+
+static DisplaySurface *ramfb_create_display_surface(int width, int height,
+                                                    pixman_format_code_t format,
+                                                    hwaddr stride, hwaddr addr)
+{
+    DisplaySurface *surface;
+    hwaddr size, mapsize, linesize;
+    void *data;
+
+    if (width < 16 || width > VBE_DISPI_MAX_XRES ||
+        height < 16 || height > VBE_DISPI_MAX_YRES ||
+        format == 0 /* unknown format */)
+        return NULL;
+
+    linesize = width * PIXMAN_FORMAT_BPP(format) / 8;
+    if (stride == 0) {
+        stride = linesize;
+    }
+
+    mapsize = size = stride * (height - 1) + linesize;
+    data = cpu_physical_memory_map(addr, &mapsize, false);
+    if (size != mapsize) {
+        cpu_physical_memory_unmap(data, mapsize, 0, 0);
+        return NULL;
+    }
+
+    surface = qemu_create_displaysurface_from(width, height,
+                                              format, stride, data);
+    pixman_image_set_destroy_function(surface->image,
+                                      ramfb_unmap_display_surface, NULL);
+
+    return surface;
+}
+
+static void ramfb_fw_cfg_write(void *dev, off_t offset, size_t len)
+{
+    RAMFBState *s = dev;
+    DisplaySurface *surface;
+    uint32_t fourcc, format, width, height;
+    hwaddr stride, addr;
+
+    width  = be32_to_cpu(s->cfg.width);
+    height = be32_to_cpu(s->cfg.height);
+    stride = be32_to_cpu(s->cfg.stride);
+    fourcc = be32_to_cpu(s->cfg.fourcc);
+    addr   = be64_to_cpu(s->cfg.addr);
+    format = qemu_drm_format_to_pixman(fourcc);
+
+    surface = ramfb_create_display_surface(width, height,
+                                           format, stride, addr);
+    if (!surface) {
+        return;
+    }
+
+    s->width = width;
+    s->height = height;
+    s->ds = surface;
+}
+
+void ramfb_display_update(QemuConsole *con, RAMFBState *s)
+{
+    if (!s->width || !s->height) {
+        return;
+    }
+
+    if (s->ds) {
+        dpy_gfx_replace_surface(con, s->ds);
+        s->ds = NULL;
+    }
+
+    /* simple full screen update */
+    dpy_gfx_update_full(con);
+}
+
+RAMFBState *ramfb_setup(Error **errp)
+{
+    FWCfgState *fw_cfg = fw_cfg_find();
+    RAMFBState *s;
+
+    if (!fw_cfg || !fw_cfg->dma_enabled) {
+        error_setg(errp, "ramfb device requires fw_cfg with DMA");
+        return NULL;
+    }
+
+    s = g_new0(RAMFBState, 1);
+
+    rom_add_vga("vgabios-ramfb.bin");
+    fw_cfg_add_file_callback(fw_cfg, "etc/ramfb",
+                             NULL, ramfb_fw_cfg_write, s,
+                             &s->cfg, sizeof(s->cfg), false);
+    return s;
+}