Add an option to let seabios show BMP file as a logo.

Signed-off-by: Wayne Xia <xiawenc@linux.vnet.ibm.com>
diff --git a/src/bmp.c b/src/bmp.c
new file mode 100644
index 0000000..0d54efd
--- /dev/null
+++ b/src/bmp.c
@@ -0,0 +1,105 @@
+/*
+* Basic BMP data process and Raw picture data handle functions.
+* Could be used to adjust pixel data format, get infomation, etc.
+*
+* Copyright (C) 2011 Wayne Xia <xiawenc@cn.ibm.com>
+*
+* This work is licensed under the terms of the GNU LGPLv3.
+*/
+#include "util.h"
+#include "bmp.h"
+
+#define bmp_load4byte(addr) (*(u32 *)(addr))
+#define bmp_load2byte(addr) (*(u16 *)(addr))
+
+typedef struct tagBITMAPFILEHEADER {
+    u8 bfType[2];
+    u8 bfSize[4];
+    u8 bfReserved1[2];
+    u8 bfReserved2[2];
+    u8 bfOffBits[4];
+} BITMAPFILEHEADER, tagBITMAPFILEHEADER;
+
+typedef struct tagBITMAPINFOHEADER {
+    u8 biSize[4];
+    u8 biWidth[4];
+    u8 biHeight[4];
+    u8 biPlanes[2];
+    u8 biBitCount[2];
+    u8 biCompression[4];
+    u8 biSizeImage[4];
+    u8 biXPelsPerMeter[4];
+    u8 biYPelsPerMeter[4];
+    u8 biClrUsed[4];
+    u8 biClrImportant[4];
+} BITMAPINFOHEADER, tagBITMAPINFOHEADER;
+
+typedef struct tagRGBQUAD {
+    u8 rgbBlue;
+    u8 rgbGreen;
+    u8 rgbRed;
+    u8 rgbReserved;
+} RGBQUAD, tagRGBQUAD;
+
+/* flat picture data adjusting function
+* description:
+*   switch the vertical line sequence
+*   arrange horizontal pixel data, add extra space in the dest buffer
+*       for every line
+*/
+static void raw_data_format_adjust_24bpp(u8 *src, u8 *dest, int width,
+                                        int height, int bytes_per_line_dest)
+{
+    int bytes_per_line_src = 3 * width;
+    int i;
+    for (i = 0 ; i < height ; i++) {
+        memcpy(dest + i * bytes_per_line_dest,
+           src + (height - 1 - i) * bytes_per_line_src, bytes_per_line_src);
+    }
+}
+
+struct bmp_decdata *bmp_alloc(void)
+{
+    struct bmp_decdata *bmp = malloc_tmphigh(sizeof(*bmp));
+    return bmp;
+}
+
+int bmp_decode(struct bmp_decdata *bmp, unsigned char *data, int data_size)
+{
+    if (data_size < 54)
+        return 1;
+
+    u16 bmp_filehead = bmp_load2byte(data + 0);
+    if (bmp_filehead != 0x4d42)
+        return 2;
+    u32 bmp_recordsize = bmp_load4byte(data + 2);
+    if (bmp_recordsize != data_size)
+        return 3;
+    u32 bmp_dataoffset = bmp_load4byte(data + 10);
+    bmp->datap = (unsigned char *)data + bmp_dataoffset;
+    bmp->width = bmp_load4byte(data + 18);
+    bmp->height = bmp_load4byte(data + 22);
+    bmp->bpp = bmp_load2byte(data + 28);
+    return 0;
+}
+
+void bmp_get_size(struct bmp_decdata *bmp, int *width, int *height)
+{
+    *width = bmp->width;
+    *height = bmp->height;
+}
+
+
+int bmp_show(struct bmp_decdata *bmp, unsigned char *pic, int width
+             , int height, int depth, int bytes_per_line_dest)
+{
+    if (bmp->datap == pic)
+        return 0;
+    /* now only support 24bpp bmp file */
+    if ((depth == 24) && (bmp->bpp == 24)) {
+        raw_data_format_adjust_24bpp(bmp->datap, pic, width, height,
+                                        bytes_per_line_dest);
+        return 0;
+    }
+    return 1;
+}