=== modified file 'include/grub/video.h' --- include/grub/video.h 2008-08-31 01:02:11 +0000 +++ include/grub/video.h 2008-08-31 06:19:25 +0000 @@ -47,10 +47,11 @@ #define GRUB_VIDEO_MODE_TYPE_DEPTH_MASK 0x0000ff00 #define GRUB_VIDEO_MODE_TYPE_DEPTH_POS 8 -/* Defined predefined render targets. */ -#define GRUB_VIDEO_RENDER_TARGET_DISPLAY ((struct grub_video_render_target *) 0) -#define GRUB_VIDEO_RENDER_TARGET_FRONT_BUFFER ((struct grub_video_render_target *) 0) -#define GRUB_VIDEO_RENDER_TARGET_BACK_BUFFER ((struct grub_video_render_target *) 1) +/* Predefined render target: */ +/* The render target that client code should render to. */ +#define GRUB_VIDEO_RENDER_TARGET_DISPLAY \ + ((struct grub_video_render_target *) 0) + /* Defined blitting formats. */ enum grub_video_blit_format @@ -267,6 +268,9 @@ grub_err_t grub_video_scroll (grub_video_color_t color, int dx, int dy); +/* Swap the pages referred to by the front buffer and back buffer render + * targets, and the page previously referred to by the back buffer is made + * visible on the display. */ grub_err_t grub_video_swap_buffers (void); grub_err_t grub_video_create_render_target (struct grub_video_render_target **result, === modified file 'video/i386/pc/vbe.c' --- video/i386/pc/vbe.c 2008-08-31 01:07:22 +0000 +++ video/i386/pc/vbe.c 2008-08-31 06:19:26 +0000 @@ -63,6 +63,7 @@ static struct { struct grub_video_render_target render_target; + int is_double_buffered; /* Is the video mode double buffered? */ unsigned int bytes_per_scan_line; unsigned int bytes_per_pixel; @@ -77,6 +78,24 @@ static grub_uint32_t mode_in_use = 0x55aa; static grub_uint16_t *mode_list; +static struct +{ + grub_size_t page_size; /* The size of a page in bytes. */ + + /* For page flipping strategy. */ + int displayed_page; /* The page # that is the front buffer. */ + int render_page; /* The page # that is the back buffer. */ + + /* For blit strategy. */ + grub_uint8_t *offscreen_buffer; + + /* Virtual functions. */ + int (*update_screen) (void); + int (*destroy) (void); +} doublebuf_state; + +static void double_buffering_init (void); + static void * real2pm (grub_vbe_farptr_t ptr) { @@ -376,6 +395,7 @@ /* Reset frame buffer and render target variables. */ grub_memset (&framebuffer, 0, sizeof(framebuffer)); render_target = &framebuffer.render_target; + grub_memset (&doublebuf_state, 0, sizeof(doublebuf_state)); return GRUB_ERR_NONE; } @@ -391,6 +411,9 @@ /* TODO: Decide, is this something we want to do. */ return grub_errno; + if (doublebuf_state.destroy) + doublebuf_state.destroy(); + /* TODO: Free any resources allocated by driver. */ grub_free (mode_list); mode_list = 0; @@ -533,9 +556,13 @@ render_target->viewport.width = active_mode_info.x_resolution; render_target->viewport.height = active_mode_info.y_resolution; - /* Set framebuffer pointer and mark it as non allocated. */ + /* Mark framebuffer memory as non allocated. */ render_target->is_allocated = 0; - render_target->data = framebuffer.ptr; + + /* Set up double buffering information. */ + framebuffer.is_double_buffered = + ((mode_type & GRUB_VIDEO_MODE_TYPE_DOUBLE_BUFFERED) != 0); + double_buffering_init (); /* Copy default palette to initialize emulated palette. */ for (i = 0; @@ -556,6 +583,166 @@ return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no matching mode found."); } +/* + Set framebuffer render target page and display the proper page, based on + `doublebuf_state.render_page' and `doublebuf_state.displayed_page', + respectively. + + Returns 0 upon success, nonzero upon failure. + */ +static int +doublebuf_pageflipping_commit (void) +{ + /* Set the render target's data pointer to the start of the render_page. */ + framebuffer.render_target.data = + ((char *) framebuffer.ptr) + + doublebuf_state.page_size * doublebuf_state.render_page; + + /* Tell the video adapter to display the new front page. */ + int display_start_line = + framebuffer.render_target.mode_info.height + * doublebuf_state.displayed_page; + + grub_vbe_status_t vbe_err = + grub_vbe_bios_set_display_start (0, display_start_line); + if (vbe_err != GRUB_VBE_STATUS_OK) + return 1; + + return 0; +} + +static int +doublebuf_pageflipping_update_screen (void) +{ + /* Swap the page numbers in the framebuffer struct. */ + int new_displayed_page = doublebuf_state.render_page; + doublebuf_state.render_page = doublebuf_state.displayed_page; + doublebuf_state.displayed_page = new_displayed_page; + + return doublebuf_pageflipping_commit (); +} + +static int +doublebuf_pageflipping_destroy (void) +{ + doublebuf_state.update_screen = 0; + doublebuf_state.destroy = 0; + return 0; +} + +static int +doublebuf_pageflipping_init (void) +{ + doublebuf_state.page_size = + framebuffer.bytes_per_scan_line * render_target->mode_info.height; + + /* Get video RAM size in bytes. */ + grub_size_t vram_size = controller_info.total_memory << 16; + + if (2 * doublebuf_state.page_size > vram_size) + return 1; /* Not enough video memory for 2 pages. */ + + doublebuf_state.displayed_page = 0; + doublebuf_state.render_page = 1; + + doublebuf_state.update_screen = doublebuf_pageflipping_update_screen; + doublebuf_state.destroy = doublebuf_pageflipping_destroy; + + /* Set the framebuffer memory data pointer and display the right page. */ + if (doublebuf_pageflipping_commit () != GRUB_ERR_NONE) + return 1; /* Unable to set the display start. */ + + framebuffer.render_target.mode_info.mode_type + |= GRUB_VIDEO_MODE_TYPE_DOUBLE_BUFFERED; + return 0; +} + +static int +doublebuf_blit_update_screen (void) +{ + grub_memcpy (framebuffer.ptr, + doublebuf_state.offscreen_buffer, + doublebuf_state.page_size); + return 0; +} + +static int +doublebuf_blit_destroy (void) +{ + grub_free (doublebuf_state.offscreen_buffer); + doublebuf_state.offscreen_buffer = 0; + + doublebuf_state.update_screen = 0; + doublebuf_state.destroy = 0; + return 0; +} + +static int +doublebuf_blit_init (void) +{ + doublebuf_state.page_size = + framebuffer.bytes_per_scan_line * render_target->mode_info.height; + + doublebuf_state.offscreen_buffer = (grub_uint8_t *) + grub_malloc (doublebuf_state.page_size); + if (doublebuf_state.offscreen_buffer == 0) + return 1; /* Error. */ + + framebuffer.render_target.data = doublebuf_state.offscreen_buffer; + doublebuf_state.update_screen = doublebuf_blit_update_screen; + doublebuf_state.destroy = doublebuf_blit_destroy; + + framebuffer.render_target.mode_info.mode_type + |= GRUB_VIDEO_MODE_TYPE_DOUBLE_BUFFERED; + return 0; +} + +static int +doublebuf_null_update_screen (void) +{ + return 0; +} + +static int +doublebuf_null_destroy (void) +{ + doublebuf_state.update_screen = 0; + doublebuf_state.destroy = 0; + return 0; +} + +static int +doublebuf_null_init (void) +{ + framebuffer.render_target.data = framebuffer.ptr; + doublebuf_state.update_screen = doublebuf_null_update_screen; + doublebuf_state.destroy = doublebuf_null_destroy; + + framebuffer.render_target.mode_info.mode_type + &= ~GRUB_VIDEO_MODE_TYPE_DOUBLE_BUFFERED; + return 0; +} + +/* Select the best double buffering mode available. */ +static void +double_buffering_init (void) +{ + if (doublebuf_state.destroy) + doublebuf_state.destroy(); + + if (framebuffer.is_double_buffered) + { + if (doublebuf_pageflipping_init () == 0) + return; + + if (doublebuf_blit_init () == 0) + return; + } + + /* Fall back to no double buffering. */ + doublebuf_null_init (); +} + static grub_err_t grub_video_vbe_get_info (struct grub_video_mode_info *mode_info) { @@ -1485,10 +1672,13 @@ return GRUB_ERR_NONE; } -static grub_err_t +static grub_err_t grub_video_vbe_swap_buffers (void) { - /* TODO: Implement buffer swapping. */ + if (doublebuf_state.update_screen () != 0) + return grub_error (GRUB_ERR_INVALID_COMMAND, + "Double buffer update failed"); + return GRUB_ERR_NONE; } @@ -1587,17 +1777,13 @@ static grub_err_t grub_video_vbe_set_active_render_target (struct grub_video_render_target *target) { - if (target == GRUB_VIDEO_RENDER_TARGET_FRONT_BUFFER) + if (target == GRUB_VIDEO_RENDER_TARGET_DISPLAY) { render_target = &framebuffer.render_target; - + return GRUB_ERR_NONE; } - if (target == GRUB_VIDEO_RENDER_TARGET_BACK_BUFFER) - return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, - "double buffering not implemented yet."); - if (! target->data) return grub_error (GRUB_ERR_BAD_ARGUMENT, "invalid render target given.");