IMX6 SL boot process is described in Chapter 8 (System Boot) of the Reference
Manual. Shortly, the loading boot data from boot SD card is performed in two stages :
first read IVT, DCD, then read executable code, using the Boot Data Structure.
At first, boot ROM copies 4K byte (containing IVT and DCD ) from sector 0
of the boot SD card to internal buffer in OCRAM, located in reserved area
(0x00900000 - 0x00907000). This area must not be used by user application.
Then, “after checking the Image Vector Table header value (0xD1) from Program
Image, the ROM code performs a DCD check. After successful DCD extraction,
the ROM code extracts from Boot Data Structure the destination pointer and length
of image to be copied to RAM device from where code execution occurs”.
The IVT contains field entry - absolute address of the first instruction to execute from
the image.
Note : according to Figure 8-3 (Internal ROM and RAM memory map), only OCRAM
Free Area (68KB) from 0x00907000 till 0x00918000 may be used by user’s application.
The attachment contains SD-bootable example.
