Does your BIOS support OEM LOGO?

Does your BIOS support OEM LOGO? This problem may disappoint you, but it is the first problem that should be solved when modifying the OEM LOGO. You may shake your head and say: "My motherboard (or BIOS) is from X (X<=3) years ago, so it cannot be supported." Don’t be sure. The author’s wrench is ASUS TX97LE (the BIOS is from March 17, 1998). At first, I thought it was impossible to support OEM LOGO, but after a series of risky experiments (using the BIOS for experiments), the author confirmed that The BIOS also supports OEM LOGO. Through the following experiments and analysis, you may also make new discoveries. It turns out that my BIOS also supports OEM LOGO.

Experiment 1:

First use PFLASH (the author uses the one that comes with the ASUS board) to back up the BIOS data to a file (such as BIOS.BIN), and type the command: CBROM BIOS .BIN /D (only CBROM version 1.26 or above has this function), the BIOS file information is displayed as follows:

No. Item-Name Original-Size Compressed-Size Original-File-Name

0. System BIOS 20000h(128.00K) 12F16h(75.77K) original.tmp

1. NCR ROM 08000h(32.00K) 04E33h(19.55K) pci32.rom

2. EPA pattern 00642h(1.56K) 002A1h(0.66K) awardepa.epa

Total compressed code space = 1B000h(108.00K)

Total compressed code size = 17FEAh (95.98K)

Remain compress code space = 03016h(12.02K)

From line 4, you can see the compressed EPA format file, but the BMP file cannot be found. Not even a trace. As can be seen from line 5?/FONT>7, the maximum compression space of the BIOS file (that is, the size of the "Total compress code space" value) is 108K, 95.98K has been used, and 12.02K is left.

If we analyze the above information using the method mentioned in the previous article, we can "certainly" judge from the two points that there is only 12.02K remaining compressed space in the BIOS file and the BMP file format cannot be found. The author's BIOS does not support OEM LOGO. But is this really the case? Let's look at it again -

Experiment 2:

The author randomly made a BMP file of 640x480 size and 16 colors, with a few words drawn on it, the size is 145K, and the file name for GOLDWAVE.BMP. First, "forcibly" implant the BMP file into BIOS.BIN and type the command: CBROM BIOS.BIN /LOGO GOLDWAVE.BMP. To the author's surprise, the process went smoothly without any error messages.

Then type: CBROM BIOS.BIN /D, then the BIOS file information is displayed:

No. Item-Name Original-Size Compressed-Size Original-File-Name

……

3. LOGO BitMap 2443Ch(145.06K) 009B5h(4.43K) goldwave.bmp

......

It can be seen from the extra line that the implant The imported BMP file Original-Size (original file size) is 145.06K, Compressed-Size (compressed file size) is 4.43K. Hey, it turns out that BMP files are compressed by the program CBROM. No wonder a small BIOS file can hold a "monster" of 145.06K.

The process of implanting pictures into the BIOS file has been successfully completed, but can I say that my BIOS fully supports OEM LOGO? Now the only way to prove it is by updating the BIOS.

The author used PFLASH to carefully burn the BIOS.BIN with the image embedded into the ROM, holding the board borrowed from a friend tightly in his arms (just in case), and shouting "Amen", he pressed RESET anxiously.

With a crisp horn sound, the familiar PCI graphics card detection information was displayed at the top of the screen. At this time, the author felt that there was no fatal problem in the BIOS. Then the screen flashed, displaying a bunch of messy-colored things (the "flower screen" I'll talk about later). If you look closely, you'll see that it was the picture you drew "casually" at the beginning, but it was completely unrecognizable, and then there was the blue sky and white clouds... …

I finally breathed a sigh of relief. The experimental results can completely prove that the author’s BIOS supports OEM LOGO. From the above and several subsequent experiments, the following conclusions can be drawn:

Whether the BIOS supports the OEM LOGO cannot be judged based on whether there is a BMP format file in the original BIOS file (this may be the reason many people have mistakes made).

The picture is compressed and then implanted into the BIOS, rather than directly. Therefore, the size of the picture file cannot be used to judge the space it occupies in the BIOS file after compression. It is judged by the number of graphics and colors in the picture (this is related to the compression algorithm). For example, two BMP pictures are both 16 colors, 640x464, and have a file size of 145K. One has several strokes on it and is only 0.52K after compression; while the other uses multiple colors and draws multiple graphics. After compression, it reaches 8K.

It can also be deduced from conclusion 2: The way to make the image (after compression) smaller is to use as few colors and simple graphics as possible in the original image, rather than just changing the pixel size of the original image.

Whether the image is larger or smaller than 640x480 pixels, the OEM LOGO will be displayed in a tiled form (the same as the WIN9X desktop background tiles), and there will be 640x16 pixels at the bottom of the OEM LOGO to display prompt information. (ie: Press [TAB] to Show POST screen, [DEL] to enter SETUP), and this information is always displayed regardless of the image size, so creating a 640x480 pixel image is not necessary, and 640x464 pixels is the most appropriate (such You can also better control the full screen display effect).

FLASH ROM (flash memory, where BIOS is stored) has a capacity of 1M and 2M, and there are generally two sizes of BIOS files, namely 126K and 256K. Assuming that the BIOS supports OEM LOGO, then the capacity of the FLASHROM and the size of the BIOS file are not used to judge whether the BIOS can hold the image file (compressed), but the remaining compressed space of the BIOS file is used to judge (i.e. " Remain compress code space" value). For example: the image is 10K after compression.

So even if your FLASH ROM capacity is 2M and the maximum compressed space of the BIOS file is 210K, but there is only 9K compressed space left in the BIOS file, it still cannot hold the picture; and your FLASH ROM capacity is 1M and the maximum compressed space of the BIOS file is only 108K , but there is still 11K of compressed space, so the picture can still be loaded. Of course, in general, the larger the BIOS file, the larger the remaining compressed space (generally 60?/FONT>120K), and the smaller the BIOS file, the smaller the remaining compressed space (generally 3?/FONT> 30K).

If after modifying the OEM LOGO, "blurred screen or discoloration" instead of "black screen or no display" appears, it will not affect system security, nor does it mean that your BIOS does not support the OEM LOGO, on the contrary. Your BIOS fully supports OEM LOGO. The reason for the "blurred screen and discoloration" is only related to the picture (how to modify the picture will be introduced later), rather than whether the BIOS supports it and the size of the BIOS space.

If there is an error in the process of implanting pictures into the BIOS file in "CBROM xxx.BIN /LOGO xxx.BMP", there are two possible reasons: one is that the BIOS does not support OEM LOGO (the author tested (I have collected dozens of BIOS files from 1996 to 1999, and no such error message has been found so far). The only solution is to leave it alone; the other is that the remaining compressed space in the BIOS file is smaller than the compressed size of the image. , the solution is to reduce the image size according to the method in Conclusion 3 (generally this will not happen with 256K BIOS files).

Since modifying the OEM LOGO is just a program called CBROM that adds image data to the BIOS file and calls its program code, it will not modify the core modules of the BIOS (including BOOT BLOCK), so if the steps in Conclusion 7 If no errors occur, then even if your BIOS does not support OEM LOGO, it will not cause a fatal BIOS error (no response at boot). Of course, failure due to operational errors and other reasons does not rule out.

In order to confirm the repeatability of the above conclusions, the author passed the experiment on another VX board (the BIOS is from April 1997). Due to conditional limitations, confirmatory experiments cannot be done on more machines, so the above conclusions may be biased in different situations, but they are applicable in most cases (at least applicable to TX and later wrenches. ).

Does your BIOS support OEM LOGO? I think your answer is very clear now, but the answer can only be decided by you. The author will not incite you to modify the BIOS. After all, this is the most dangerous thing in computer operation (it depends on who has the "luck" to experience it personally) ), the author will not be responsible for any losses caused (who is throwing eggs!).

Create a LOGO picture

Before writing this article, many friends must have tried to modify the OEM LOGO, but they may find "flower screen" or "discoloration" (that is, the picture is This color, but it is displayed in other colors) phenomenon, which makes the carefully designed LOGO completely unrecognizable. Many friends think that they can create a LOGO image by just using the "Save as 16-color bitmap" function of the drawing program. In fact, things are not as simple as imagined, and the problem lies in the LOGO image. Therefore, before creating a picture, it is necessary to understand the file format of the LOGO picture.

In the article "Modify BIOS LOGO FAQ" in the 20th issue, it was mentioned that this file format is an "unknown binary format file". The reason why I think so is that "CBROM XXX" was used. .BIN /LOGO EXTRACT" function to extract pictures from the BIOS file, but the picture files extracted by this function are completely different from the picture files originally implanted in the BIOS (although the file size is the same). The extracted file is indeed an "unknown binary format file", but the picture file implanted in the BIOS is a standard 16-color "index" bitmap file.

In fact, bitmap files (BITMAP, i.e. BMP files) are divided into two categories in terms of file formats. One is the familiar "RGB" format, which uses "R, G, B" red, The three colors of green and blue represent the color of a point. For example, if a certain point is blue, then the code "00 00 FF" is used to represent the color of this point. Since each of the three RGB quantities can take on 256 values ??(0 to FF), up to 16M (256^3) colors can be displayed. The other type is the "INDEX" (index) format. Files in this format first create a color table in the file header (starting from 3CH) (the color table can be viewed with programs such as PHOTOSHOP), and then are represented by the color codes in the color table. Every bit of color. For example, if the color at position 15 in the color table is blue and the color at a certain point is also blue, then use 0F (hexadecimal) to represent the color at this point instead of "00 00 FF" in the RGB format. express. An "indexed" bitmap can only display up to 256 (2^8) colors.

The above briefly introduces the format of bitmap files, so what is the reason for the "hua screen"? It turns out that the colors in the general 16-color index bitmap color table can be any 16 of the 16M colors, but the LOGO picture is a standard 16-color index bitmap file, and its color table can only be the predetermined 16 colors. If the colors in the color table are not these 16 or exceed these 16, it will cause a "blurred screen" phenomenon during display. Judging from the reason, the solution is very simple, that is, create the LOGO image into a standard 16-color "index" bitmap file (this can be done by saving as "16-color bitmap" in the "Paint" program).

The reason for "discoloration" is not that simple compared to "discoloration". Since I don't know how the BIOS displays the LOGO picture (it is definitely different from the general program), so I can't figure it out. We basically understand the reason, but an interesting phenomenon is that the "discoloration" results of CBROM versions 1.03 and 1.3 are actually different. Version 1.03 turns red into light red, but version 1.3 turns red into gray (sometimes into Other colors), the "discoloration" of version 1.03 is not very serious, while the "discoloration" of version 1.3 is simply a pretentious change, and the effect is very poor. From this, it can also be determined that the image is processed by the CBROM program and then compressed into the BIOS file, and the CBROM program will also affect the discoloration.

Does the above analysis mean that it is impossible to avoid "discoloration"? In fact, as long as the process of creating pictures meets certain standards, it can basically guarantee that the pictures will not "discolor". The following is the author's drawing experience in operation:

If you are interested in PHOTOSHOP (hereinafter referred to as "PS") ") are not very proficient, it is recommended to use the paintbrush program that comes with WINDOWS for drawing. There are two reasons for this: First, you can use the "save as '16-color bitmap'" of the paintbrush program to create a 16-color index bitmap that meets the requirements. PS needs to go through various steps such as "converting to index mode" and processing the color table. Second, due to the strong PS function, it will perform special processing on the image in RGB mode, which will make the image prone to "discoloration"

When drawing, it is best to use black as the background color and blue as the background color. The color is the text and graphic color. In addition, some green or white can be added, and other colors should be used sparingly. For example, in the "Jinchao Computer" shown in Figure 1 (have you heard of this brand), except for the word "Chao" in green, the rest are blue, and there is no "discoloration" in this picture.

If you use a brush, just pay attention to the use of colors, and then use "Save as '16-color bitmap'" after drawing. When using PS, you must first convert the "RGB mode" to the "INDEX mode" (since this process also requires a color table, the easiest way is to first use the brush program to create a 16-color index bitmap, and then use Open PS) and then draw. Because in the "RGB" mode, PS will "anti-alias the edges" of the image (that is, fill the edges with similar colors), and this will easily cause "discoloration".

Try to draw regular graphics such as straight lines and rectangles, and less curves and circles. Otherwise, the "jaggies" phenomenon will be serious in the final display, affecting the overall effect of the LOGO image.

It is best to use CBROM version 1.03 to implant pictures, because even discoloration will not be serious.

For other considerations when creating images, please refer to items 2, 3, and 4 in the conclusion.

The result of the above experience is the "Golden Chao Computer" shown in Figure 1 (who is drooling), which does not change color in the final display. Of course, if you feel that creating pictures is too troublesome, you can also download pre-made LOGO pictures from my website (all of them are wonderful and will not change color. There is also a matching WIN9X animated boot LOG, so download it quickly!)

The final "surgery"

It's finally time to perform "surgery" on the BIOS. If you have experience in modifying the BIOS, it is now very easy. First run a BIOS update program such as AWDFLASH (it is recommended to use the one provided by the motherboard manufacturer, such as ASUS's PFLASH), save the data in the BIOS to the file XXX.BIN (for specific operations, please refer to the relevant article, I will not go into details here), and then Type CBROM XXX.BIN /LOGO XXX.BMP to embed the completed LOGO image into the BIOS file, and finally use AWDFLASH to update the BIOS file with the embedded image into the ROM. Okay, that's it! oh! Don’t worry, and sincerely pray to God. After turning on the phone, you will see your carefully designed LOGO, but not the “green smoke” effect with poor sound, light and smell effects (have you seen it? It’s very “wonderful” "of!).

Now that I have finished nagging (my hands are so sore!), I still have to say an old saying: BIOS modifications are dangerous, and you must be careful during the modification process to avoid losses! The programs, LOGO pictures and more detailed information mentioned in this article can be downloaded from .