1*c0880485SNikita KiryanovIf you are experiencing hangups/data-aborts when trying to display a BMP image, 2*c0880485SNikita Kiryanovthe following might be relevant to your situation... 3*c0880485SNikita Kiryanov 4*c0880485SNikita KiryanovSome architectures cannot handle unaligned memory accesses, and an attempt to 5*c0880485SNikita Kiryanovperform one will lead to a data abort. On such architectures it is necessary to 6*c0880485SNikita Kiryanovmake sure all data is properly aligned, and in many situations simply choosing 7*c0880485SNikita Kiryanova 32 bit aligned address is enough to ensure proper alignment. This is not 8*c0880485SNikita Kiryanovalways the case when dealing with data that has an internal layout such as a 9*c0880485SNikita KiryanovBMP image: 10*c0880485SNikita Kiryanov 11*c0880485SNikita KiryanovBMP images have a header that starts with 2 byte-size fields followed by mostly 12*c0880485SNikita Kiryanov32 bit fields. The packed struct that represents this header can be seen below: 13*c0880485SNikita Kiryanov 14*c0880485SNikita Kiryanovtypedef struct bmp_header { 15*c0880485SNikita Kiryanov /* Header */ 16*c0880485SNikita Kiryanov char signature[2]; 17*c0880485SNikita Kiryanov __u32 file_size; 18*c0880485SNikita Kiryanov __u32 reserved; 19*c0880485SNikita Kiryanov __u32 data_offset; 20*c0880485SNikita Kiryanov ... etc 21*c0880485SNikita Kiryanov} __attribute__ ((packed)) bmp_header_t; 22*c0880485SNikita Kiryanov 23*c0880485SNikita KiryanovWhen placed in an aligned address such as 0x80a00000, char signature offsets 24*c0880485SNikita Kiryanovthe __u32 fields into unaligned addresses (in our example 0x80a00002, 25*c0880485SNikita Kiryanov0x80a00006, and so on...). When these fields are accessed by U-Boot, a 32 bit 26*c0880485SNikita Kiryanovaccess is generated at a non-32-bit-aligned address, causing a data abort. 27*c0880485SNikita KiryanovThe proper alignment for BMP images is therefore: 32-bit-aligned-address + 2. 28