KiSS DP-450 and DP-500 fonts
Overview
The only interesting file for us is /bin/init contained in romfs.bin.
kx:# mount -o loop 'KiSS DP-450 Firmware 2.7.1 PAL.iso' /mnt/dp450
kx:# mount -o loop /mnt/dp450/romfs.bin /mnt/dp450.romfs
kx:$ cd /mnt/dp450.romfs
kx:/mnt/dp450.romfs$ ls -l bin
total 0
-rwxr-xr-x 1 root root 57528 Jan 1 1970 busybox
-rwxr-xr-x 1 root root 875428 Jan 1 1970 init
To create new romfs.bin, I use:
genromfs -d newromfs -f /tmp/romfs.bin -a 512 -V 'romfs'
If you need documentation on extracting files and assembling them back on windows, please refer to www.kiss-tuning.nl.
KiSS programmers use the NANO-X
graphical library, probably version 0.89. Unfortunately it is statically
linked with bin/init, what will not make our life easier. :-(
The following fonts are defined:
- 24-pixel font containing many European characters from different
character sets
- some bigger versions of above, not interesting because not used in
current versions
- font with many icons, symbols, arrows - not interesting either
- 16-pixel font Japanese (?) or
Korean font - unfortunately interesting, because sometimes displayed
- we will have to disable it.
Each font has three interesting structures:
- characters' definitions
- table of pointers to font definitions
- table of characters' width
Description of 24-pixel font follows.
Fonts
Characters' definitions
Each character is defined in 16x24 grid (width x height) or 32x24 grid.
Most characters fit into the smaller one, only some of them don't (%, @,
W, m, (C), (R), 1/4, 1/2, 3/4 an so on - you can find them yourself -
they look a bit strange on my picture, because
I displayed them like any other character ignoring the fact they use
twice as space). But I had a very good reason for making it looks like
this - it is very handy when we need the address of a character
from the table.
16x24 grid characters are encoded as 24 16-bit words, where the most
significant bit is on the left side of the character. Words are little
endian (low byte, high byte).
An example:
FEDCBA9876543210
1 ........XXX..... 32+64+128 = 224 0x00E0
2 .......X...X.... 16+256 = 272 0x0110
3 ........XXX..... 32+64+128 = 224 0x00E0
...
24 ................
E0, 00, 10, 01, E0, 00, ...
32x24 grid characters are encoded as 24 pairs of 16-bit words, where the
first word is the left side of the row of the character.
So normal character uses 48 bytes and wider one - 96 bytes).
Table of pointers
Some characters use 48 bytes, some 96, so we can't compute the address
of the definition of a given characters. These addresses are stored in
the table. Table stores 2-byte words (little endian).
The table starts with the address of the space character
(code 32). The address of the space is 0. The address of the next character ("!") is...
no, not 48 ;-) It would be too easy. You need to divide it by 2 :)
So the address of "!" is 24.
This table has a nice advantage which I used to make a version with
Polish characters. There are two encoding standards used in Poland
- iso-8859-2 and windows-1250. Unfortunately, they are different!
But it is possible to make a firmware which displays both standards
correctly. For example, character "¶" is 0xB6 in iso-8859-2 and 0x9C
in windows-1250. So I set both pointers (for 0xB6 and 0x9C characters) to
the same value - the address of the "¶" character - 0x127 * 48 / 2 = 7080
In the C syntax: ptr_table [0xB6 - ' '] = ptr_table [0x9C - ' '] = 7080;
And that's all (well, almost all - we need one more step).
Table of characters' width
This table of bytes stores the width of characters. First element is
a width of space, second of "!" and so on. To complete defining "¶"
character in iso-8859-2 and windows-1250 we need to set it's width.
width_table [0xB6 - ' '] = width_table [0x9C - ' '] = w;
where w is of course the width of our "¶".
Problem with Korean characters
KiSS has configured the NANO-X
library to handle Korean fonts,
probably by defining HAVE_EUCJP_SUPPORT or HAVE_KSC5601_SUPPORT macro.
As we can see in microwin-0.89/src/engine/devfont.c this support is done
by decoding two-byte sequences into one character.
This is described as bug "Bad display of extended
Latin characters in menus and subtitles" in the
bugs
thread of the
Kiss DVD
software forum.
To disable this "feature" we need to change two bytes from "1" to "0"
at offsets shown below as "Disabling Korean encoding".
File offsets
| FW version | Characters' definitions | Table of pointers | Table of widths | Disabling Korean encoding |
| DP-450 2.7.4 | 610240 | 644176 | 648406 | 406176 and 446044 |
| DP-500 2.7.4 | 812664 | 846600 | 850830 | 453520 and 493388 |
Adding custom font
Adding a custom font requires the following steps:
- Add your font definition. I have added cyrillic font at the end of the
current font table - 16032 bytes from the beginning.
- Map the characters to the new font (table of pointers).
- Define the right width for all new characters (table of widths).
