From 995b30179bdc97a01ff2e4e0dce07f3e9b7d7d7d Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Wed, 13 Jun 2018 14:29:45 +0200 Subject: [PATCH] hw/display: add ramfb, a simple boot framebuffer living in guest ram The boot framebuffer is expected to be configured by the firmware, so it uses fw_cfg as interface. Initialization goes as follows: (1) Check whenever etc/ramfb is present. (2) Allocate framebuffer from RAM. (3) Fill struct RAMFBCfg, write it to etc/ramfb. Done. You can write stuff to the framebuffer now, and it should appear automagically on the screen. Note that this isn't very efficient because it does a full display update on each refresh. No dirty tracking. Dirty tracking would have to be active for the whole ram slot, so that wouldn't be very efficient either. For a boot display which is active for a short time only this isn't a big deal. As permanent guest display something better should be used (if possible). This is the ramfb core code. Some windup is needed for display devices which want have a ramfb boot display. Signed-off-by: Gerd Hoffmann Tested-by: Laszlo Ersek Message-id: 20180613122948.18149-2-kraxel@redhat.com Signed-off-by: Gerd Hoffmann --- hw/display/Makefile.objs | 2 + hw/display/ramfb.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++ include/hw/display/ramfb.h | 9 +++++ 3 files changed, 106 insertions(+) create mode 100644 hw/display/ramfb.c create mode 100644 include/hw/display/ramfb.h diff --git a/hw/display/Makefile.objs b/hw/display/Makefile.objs index b5d97ab26d..0af04985d2 100644 --- a/hw/display/Makefile.objs +++ b/hw/display/Makefile.objs @@ -1,3 +1,5 @@ +common-obj-y += ramfb.o + common-obj-$(CONFIG_ADS7846) += ads7846.o common-obj-$(CONFIG_VGA_CIRRUS) += cirrus_vga.o common-obj-$(CONFIG_G364FB) += g364fb.o diff --git a/hw/display/ramfb.c b/hw/display/ramfb.c new file mode 100644 index 0000000000..6867bce8ae --- /dev/null +++ b/hw/display/ramfb.c @@ -0,0 +1,95 @@ +/* + * early boot framebuffer in guest ram + * configured using fw_cfg + * + * Copyright Red Hat, Inc. 2017 + * + * Author: + * Gerd Hoffmann + * + * 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 "ui/console.h" +#include "sysemu/sysemu.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_fw_cfg_write(void *dev, off_t offset, size_t len) +{ + RAMFBState *s = dev; + void *framebuffer; + uint32_t stride, fourcc, format; + hwaddr addr, length; + + s->width = be32_to_cpu(s->cfg.width); + s->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); + length = stride * s->height; + format = qemu_drm_format_to_pixman(fourcc); + + fprintf(stderr, "%s: %dx%d @ 0x%" PRIx64 "\n", __func__, + s->width, s->height, addr); + framebuffer = address_space_map(&address_space_memory, + addr, &length, false, + MEMTXATTRS_UNSPECIFIED); + if (!framebuffer || length < stride * s->height) { + s->width = 0; + s->height = 0; + return; + } + s->ds = qemu_create_displaysurface_from(s->width, s->height, + format, stride, framebuffer); +} + +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); + + fw_cfg_add_file_callback(fw_cfg, "etc/ramfb", + NULL, ramfb_fw_cfg_write, s, + &s->cfg, sizeof(s->cfg), false); + return s; +} diff --git a/include/hw/display/ramfb.h b/include/hw/display/ramfb.h new file mode 100644 index 0000000000..a3d4c79942 --- /dev/null +++ b/include/hw/display/ramfb.h @@ -0,0 +1,9 @@ +#ifndef RAMFB_H +#define RAMFB_H + +/* ramfb.c */ +typedef struct RAMFBState RAMFBState; +void ramfb_display_update(QemuConsole *con, RAMFBState *s); +RAMFBState *ramfb_setup(Error **errp); + +#endif /* RAMFB_H */ -- 2.11.4.GIT