diff options
Diffstat (limited to 'hw/display')
| -rw-r--r-- | hw/display/bcm2835_fb.c | 48 |
1 files changed, 46 insertions, 2 deletions
diff --git a/hw/display/bcm2835_fb.c b/hw/display/bcm2835_fb.c index 76a10072b4..3edb8b5cfc 100644 --- a/hw/display/bcm2835_fb.c +++ b/hw/display/bcm2835_fb.c @@ -34,6 +34,13 @@ #define DEFAULT_VCRAM_SIZE 0x4000000 #define BCM2835_FB_OFFSET 0x00100000 +/* Maximum permitted framebuffer size; experimentally determined on an rpi2 */ +#define XRES_MAX 3840 +#define YRES_MAX 2560 +/* Framebuffer size used if guest requests zero size */ +#define XRES_SMALL 592 +#define YRES_SMALL 488 + static void fb_invalidate_display(void *opaque) { BCM2835FBState *s = BCM2835_FB(opaque); @@ -202,6 +209,45 @@ static void fb_update_display(void *opaque) s->invalidate = false; } +void bcm2835_fb_validate_config(BCM2835FBConfig *config) +{ + /* + * Validate the config, and clip any bogus values into range, + * as the hardware does. Note that fb_update_display() relies on + * this happening to prevent it from performing out-of-range + * accesses on redraw. + */ + config->xres = MIN(config->xres, XRES_MAX); + config->xres_virtual = MIN(config->xres_virtual, XRES_MAX); + config->yres = MIN(config->yres, YRES_MAX); + config->yres_virtual = MIN(config->yres_virtual, YRES_MAX); + + /* + * These are not minima: a 40x40 framebuffer will be accepted. + * They're only used as defaults if the guest asks for zero size. + */ + if (config->xres == 0) { + config->xres = XRES_SMALL; + } + if (config->yres == 0) { + config->yres = YRES_SMALL; + } + if (config->xres_virtual == 0) { + config->xres_virtual = config->xres; + } + if (config->yres_virtual == 0) { + config->yres_virtual = config->yres; + } + + if (fb_use_offsets(config)) { + /* Clip the offsets so the viewport is within the physical screen */ + config->xoffset = MIN(config->xoffset, + config->xres_virtual - config->xres); + config->yoffset = MIN(config->yoffset, + config->yres_virtual - config->yres); + } +} + static void bcm2835_fb_mbox_push(BCM2835FBState *s, uint32_t value) { uint32_t pitch; @@ -238,8 +284,6 @@ void bcm2835_fb_reconfigure(BCM2835FBState *s, BCM2835FBConfig *newconfig) { s->lock = true; - /* TODO: input validation! */ - s->config = *newconfig; s->invalidate = true; |