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fbsplash: support 8bit mode

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Fake truecolor support using a RGB:332 palette.

function                                             old     new   delta
fb_setpal                                              -     172    +172
fbsplash_main                                        920     953     +33
fb_pixel_value                                        50      80     +30
fb_write_pixel                                        47      51      +4
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/0 up/down: 239/0)             Total: 239 bytes

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Peter Korsgaard 2011-10-17 05:31:52 +02:00 committed by Denys Vlasenko
parent e4fa7b7965
commit cd06e06eee
1 changed files with 64 additions and 5 deletions
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69
miscutils/fbsplash.c
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@ -74,6 +74,43 @@ struct globals {
#define DEBUG_MESSAGE(...) ((void)0)
#endif
/**
* Configure palette for RGB:332
*/
static void fb_setpal(int fd)
{
struct fb_cmap cmap;
/* fb colors are 16 bit */
unsigned short red[256], green[256], blue[256];
unsigned i;
/* RGB:332 */
for (i = 0; i < 256; i++) {
/* Color is encoded in pixel value as rrrgggbb.
* 3-bit color is mapped to 16-bit one as:
* 000 -> 00000000 00000000
* 001 -> 00100100 10010010
* ...
* 011 -> 01101101 10110110
* 100 -> 10010010 01001001
* ...
* 111 -> 11111111 11111111
*/
red[i] = (( i >> 5 ) * 0x9249) >> 2; // rrr * 00 10010010 01001001 >> 2
green[i] = (((i >> 2) & 0x7) * 0x9249) >> 2; // ggg * 00 10010010 01001001 >> 2
/* 2-bit color is easier: */
blue[i] = ( i & 0x3) * 0x5555; // bb * 01010101 01010101
}
cmap.start = 0;
cmap.len = 256;
cmap.red = red;
cmap.green = green;
cmap.blue = blue;
cmap.transp = 0;
xioctl(fd, FBIOPUTCMAP, &cmap);
}
/**
* Open and initialize the framebuffer device
@ -87,8 +124,21 @@ static void fb_open(const char *strfb_device)
xioctl(fbfd, FBIOGET_VSCREENINFO, &G.scr_var);
xioctl(fbfd, FBIOGET_FSCREENINFO, &G.scr_fix);
if (G.scr_var.bits_per_pixel < 16 || G.scr_var.bits_per_pixel > 32)
switch (G.scr_var.bits_per_pixel) {
case 8:
fb_setpal(fbfd);
break;
case 16:
case 24:
case 32:
break;
default:
bb_error_msg_and_die("unsupported %u bpp", (int)G.scr_var.bits_per_pixel);
break;
}
G.bytes_per_pixel = (G.scr_var.bits_per_pixel + 7) >> 3;
// map the device in memory
@ -109,11 +159,17 @@ static void fb_open(const char *strfb_device)
*/
static unsigned fb_pixel_value(unsigned r, unsigned g, unsigned b)
{
if (G.bytes_per_pixel == 1) {
r = r & 0xe0; // 3-bit red
g = (g >> 3) & 0x1c; // 3-bit green
b = b >> 6; // 2-bit blue
return r + g + b;
}
if (G.bytes_per_pixel == 2) {
r >>= 3; // 5-bit red
g >>= 2; // 6-bit green
b >>= 3; // 5-bit blue
return b + (g << 5) + (r << (5+6));
r = (r & 0xf8) << 8; // 5-bit red
g = (g & 0xfc) << 3; // 6-bit green
b = b >> 3; // 5-bit blue
return r + g + b;
}
// RGB 888
return b + (g << 8) + (r << 16);
@ -125,6 +181,9 @@ static unsigned fb_pixel_value(unsigned r, unsigned g, unsigned b)
static void fb_write_pixel(unsigned char *addr, unsigned pixel)
{
switch (G.bytes_per_pixel) {
case 1:
*addr = pixel;
break;
case 2:
*(uint16_t *)addr = pixel;
break;