Archos 5 Boot Logo

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The boot logo is located in flash memory at address 0x060000. It is a gzip archive containing a file named i800x480 (without file extension). The file contains one 4-bytes word for each pixel on the screen: 800 * 480 * 4 bytes = 1,536,000 bytes, which is the exact size of the uncompressed i800x480 file.

Replacing the boot logo

This is a step-by-step guide to replacing the boot logo. As it is not signed, you can easily flash a new one, assuming you have a shell on your device.

Creating a compatible logo

To create a boot logo in GIMP, create a new 800x480 image with Fill with = Transparency in Advanced Options. Flip your image vertically (upside down) before saving it, otherwise it will not be displayed properly on the device. Save it as a .bmp file and make sure A8 R8 G8 B8 under 32 bit is selected in the Advanced Options dialog. The output file will be 1,536,054 bytes long, because it is prefixed with a 54-bytes BMP header. Strip the header with:

dd if=logo.bmp of=i800x480 bs=54 skip=1

and make sure the file is now 1,536,000 bytes. The next step is to gzip-compress your i800x480 file, and you are ready to flash it on your device. If the gzipped file is over 128kb, it will overflow in the area reserved to the recovery kernel, so make sure to use gzip -9 i800x480 for maximum compression.

Flashing the logo

The flashing process is very delicate, it comes with the usual warning: if you type the command wrong or if you don't know what you are doing you will brick your device. To flash the i800x480.gz file to your device, we have created a small utility named flash, available with the target-tools from the aos toolchain. Copy flash and i800x480.gz to your device. The following command must be executed from a shell on your device, it will copy the contents of i800x480.gz to the address 0x060000 in the flash memory of your device:

flash -f i800x480.gz 0x060000

Now assuming the flash was successful, reboot your device to see what your logo looks like :)

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