Geoff Chappell, Software Analyst
The SYSTEM_BOOT_LOGO_INFORMATION structure is what a successful call to ZwQuerySystemInformation or NtQuerySystemInformation produces at the start of its output buffer when given the information class SystemBootLogoInformation (0x8C).
The structure is a fixed-size header to introduce the variable-size bitmap that the boot logo is displayed from.
The SYSTEM_BOOT_LOGO_INFORMATION structure is not documented.
The SYSTEM_BOOT_LOGO_INFORMATION is 0x08 bytes in both 32-bit and 64-bit Windows.
The only bit that is defined for the Flags is 0x00000001. If set, it denotes that the logo is an OEM bitmap (from ACPI tables), not a resource bitmap (from bootres.dll).
The BitmapOffset is the offset in bytes to the bitmap from the start of the structure. If only for now, this is 0x08 because the bitmap follows the structure immediately. The bitmap might in principle have any format. If only for the PCAT loader in Windows 10, the format can only be the usual Windows bitmap, i.e., beginning with a BITMAPFILEHEADER.