qemu sdl开发 demo

以下是一个简单的QEMU SDL界面的示例代码，可以用来启动x86架构的虚拟机：

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <SDL2/SDL.h>
#include "qemu-common.h"
#include "qemu-option.h"
#include "qemu-options.h"
#include "qemu-config.h"
#include "sysemu/sysemu.h"
#include "ui/console.h"
#include "ui/sdl.h"

#define DEFAULT_WIDTH 800
#define DEFAULT_HEIGHT 600

static SDL_Window *sdl_window = NULL;
static SDL_Renderer *sdl_renderer = NULL;
static SDL_Texture *sdl_texture = NULL;
static int sdl_width = DEFAULT_WIDTH;
static int sdl_height = DEFAULT_HEIGHT;
static int sdl_stride = DEFAULT_WIDTH * 4;

static bool sdl_init()
{
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        fprintf(stderr, "SDL_Init failed: %s\n", SDL_GetError());
        return false;
    }
    sdl_window = SDL_CreateWindow("QEMU SDL Demo",
                                  SDL_WINDOWPOS_UNDEFINED,
                                  SDL_WINDOWPOS_UNDEFINED,
                                  sdl_width, sdl_height,
                                  SDL_WINDOW_SHOWN);
    if (!sdl_window) {
        fprintf(stderr, "SDL_CreateWindow failed: %s\n", SDL_GetError());
        return false;
    }
    sdl_renderer = SDL_CreateRenderer(sdl_window, -1, SDL_RENDERER_ACCELERATED);
    if (!sdl_renderer) {
        fprintf(stderr, "SDL_CreateRenderer failed: %s\n", SDL_GetError());
        return false;
    }
    sdl_texture = SDL_CreateTexture(sdl_renderer,
                                    SDL_PIXELFORMAT_ARGB8888,
                                    SDL_TEXTUREACCESS_STREAMING,
                                    sdl_width, sdl_height);
    if (!sdl_texture) {
        fprintf(stderr, "SDL_CreateTexture failed: %s\n", SDL_GetError());
        return false;
    }
    return true;
}

static void sdl_render(uint8_t *pixels)
{
    SDL_UpdateTexture(sdl_texture, NULL, pixels, sdl_stride);
    SDL_RenderClear(sdl_renderer);
    SDL_RenderCopy(sdl_renderer, sdl_texture, NULL, NULL);
    SDL_RenderPresent(sdl_renderer);
}

static void qemu_exit(int ret)
{
    SDL_DestroyTexture(sdl_texture);
    SDL_DestroyRenderer(sdl_renderer);
    SDL_DestroyWindow(sdl_window);
    SDL_Quit();
    exit(ret);
}

int main(int argc, char **argv)
{
    int ret;
    QemuOpts *opts;
    const char *machine_type, *kernel_path, *initrd_path, *cmdline;
    const char *device_opts;
    qemu_init_main_loop(&argc, &argv);
    if (!sdl_init()) {
        fprintf(stderr, "SDL init failed\n");
        qemu_exit(1);
    }
    opts = qemu_opts_parse(qemu_find_opts("qemu"), argc, argv, 0);
    machine_type = qemu_opt_get(opts, "machine", "pc-i440fx-2.9");
    kernel_path = qemu_opt_get(opts, "kernel", NULL);
    initrd_path = qemu_opt_get(opts, "initrd", NULL);
    cmdline = qemu_opt_get(opts, "append", NULL);
    device_opts = qemu_opt_get(opts, "device", NULL);
    ret = qemu_run_machine(machine_type, kernel_path, initrd_path,
                            cmdline, device_opts, sdl_render);
    qemu_opts_del(opts);
    qemu_exit(ret);
}

该示例代码使用SDL库实现了一个简单的窗口，用于显示虚拟机的图像输出。在main()函数中，首先调用sdl_init()函数初始化SDL库，并创建一个窗口、渲染器和纹理对象。然后使用qemu_opts_parse()函数解析命令行参数，获取虚拟机的配置信息。最后调用qemu_run_machine()函数启动虚拟机，并在sdl_render()函数中更新纹理内容，实现图像的显示。

需要注意的是，这只是一个简单的示例代码，实际开发中需要考虑更多的细节和功能实现。同时，由于QEMU的内部实现比较复杂，需要一定的QEMU开发经验才能够理解和修改代码。