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Diffstat (limited to 'Documentation/boards')
| -rw-r--r-- | Documentation/boards/imx.rst | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/Documentation/boards/imx.rst b/Documentation/boards/imx.rst index a8f014dd1b..2a51681906 100644 --- a/Documentation/boards/imx.rst +++ b/Documentation/boards/imx.rst @@ -394,6 +394,86 @@ with only the image name as argument: scripts/imx/imx-usb-loader images/barebox-freescale-imx51-babbage.img +FlexSPI Boot +^^^^^^^^^^^^ + +FlexSPI boot is currently supported on: i.MX8MM, i.MX8MN and i.MX8MP. + +To generate FlexSPI/QSPI image(s) the board flash header file must specify: +``flexspi_ivtofs`` and ``flexspi_fcfbofs``. + +It is recommended to do this via the ``include/mach/imx/flexspi-imx8m*-cfg.h`` +header files. + +.. code-block:: none + + #include <mach/imx/flexspi-imx8mp-cfg.h> + +There are two different headers, one for the i.MX8MM and one for the i.MX8MP/N. +It's important to use the correct one because the BootROM expects the IVT and +flash configuration block (FCB) on different offsets. + +Barebox doesn't generate a separate FlexSPI image instead the same image used +for SD/MMC/USB is extended to support FlexSPI boot. This is done by adding a 2nd +IVT header and the required FCB at the required boot offsets. + +Barebox also support `High Assurance Boot`_ images for QSPI boot mediums. This +feature must be enabled via the ``CONFIG_HABV4_QSPI`` option. The below figures +show a fully featured MMC/SD/USB/FlexSPI image with enabled HAB support for the +i.MX8M family. + +i.MX8MM layout:: + + 0x0 +------------------------------------------+ + | Barebox Header | + header_gap +------------------------------------------+ + | FlexSPI Flash Configuration Block (FCFB) | + header_gap + 0x400 +------------------------------------------+ --- + | i.MX MMC/SD/USB IVT Header | | + | Boot Data +--. | + | CSF Pointer +--|--. | + header_gap + 0x1000 +------------------------------------------+ | | --- | + | i.MX FlexSPI IVT Header | | | | | Signed Area + | Boot Data +--+ | | | MMC/SD/ + | CSF Pointer +--|--|--. | Signed Area | USB + header_gap + 0x2000 +------------------------------------------+ | | | | FlexSPI | + | Barebox Prebootloader (PBL) |<-´ | | | | + | Piggydata Hash (SHA256) | | | | | + +------------------------------------------+ | | --- --- + | Command Sequence File (CSF) Slot-0 |<----´ | + +------------------------------------------+ | + | Command Sequence File (CSF) Slot-1 |<-------´ + +------------------------------------------+ --- + | Piggydata (Main Barebox Binary) | | Hashed Area + +------------------------------------------+ --- + +i.MX8MP/N layout:: + + 0x0 +------------------------------------------+ + | Barebox Header | + header_gap +------------------------------------------+ --- + | i.MX MMC/SD/USB IVT Header | | + | Boot Data +--. | + | CSF Pointer +--|--. | + header_gap + 0x400 +------------------------------------------+ | | | + | FlexSPI Flash Configuration Block (FCFB) | | | | Signed Area + header_gap + 0x1000 +------------------------------------------+ | | --- | MMC/SD/ + | i.MX FlexSPI IVT Header | | | | | USB + | Boot Data +--+ | | | + | CSF Pointer +--|--|--. | Signed Area | + header_gap + 0x2000 +------------------------------------------+ | | | | FlexSPI | + | Barebox Prebootloader (PBL) |<-´ | | | | + | Piggydata Hash (SHA256) | | | | | + +------------------------------------------+ | | --- --- + | Command Sequence File (CSF) Slot-0 |<----´ | + +------------------------------------------+ | + | Command Sequence File (CSF) Slot-1 |<-------´ + +------------------------------------------+ --- + | Piggydata (Main Barebox Binary) | | Hashed Area + +------------------------------------------+ --- + +At the moment ``header_gap`` is always 32K for all supported devices. + External Boot Mode ------------------ |