diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/boards/imx.rst | 73 | ||||
| -rw-r--r-- | Documentation/boards/imx/embest-marsboard.rst | 82 | ||||
| -rw-r--r-- | Documentation/boards/imx/zii-vf610-dev/openocd.cfg | 8 | ||||
| -rw-r--r-- | Documentation/devicetree/index.rst | 59 | ||||
| -rw-r--r-- | Documentation/user/barebox.rst | 1 |
5 files changed, 216 insertions, 7 deletions
diff --git a/Documentation/boards/imx.rst b/Documentation/boards/imx.rst index 71cc6bb09a..8fe0a2828d 100644 --- a/Documentation/boards/imx.rst +++ b/Documentation/boards/imx.rst @@ -142,6 +142,79 @@ It must be included in the board's flash header: Analogous to HABv4 options and a template exist for HABv3. +Secure Boot on i.MX6 +~~~~~~~~~~~~~~~~~~~~ + +For most boards, the secure boot process on i.MX6 consist of the following image +constellation:: + + 0x0 +---------------------------------+ + | Barebox Header | + 0x400 +---------------------------------+ - + | i.MX IVT Header | | + | Boot Data +--+ | + | CSF Pointer +--|-+ | Signed Area + +---------------------------------+ | | | + | Device Configuration Data (DCD) | | | | + 0x1000 +---------------------------------+ | | | + | Barebox Prebootloader (PBL) |<-+ | | + +---------------------------------+ | | + | Piggydata (Main Barebox Binary) | | | + +---------------------------------+ | - + | Command Sequence File (CSF) |<---+ + +---------------------------------+ + +Here the Command Sequence File signs the complete Header, PBL and piggy data +file. This ensures that the whole barebox binary is authenticated. This is +possible since the DDR RAM is configured using the DCD and the whole DDR memory +area can be used to load data onto the device for authentication. +The boot ROM loads the CSF area and barebox into memory and uses the CSF to +verify the complete barebox binary. + +Boards which do require a boot via SRAM, need changes akin to the implementation +for i.MX8MQ described in the next chapter. + +Secure Boot on i.MX8MQ +~~~~~~~~~~~~~~~~~~~~~~ + +For i.MX8MQ the image has the following design:: + + 0x0 +---------------------------------+ + | Barebox Header | + +---------------------------------+ + | i.MX IVT Header | + | HDMI Firmware (Signed by NXP) | + +---------------------------------+ - + | i.MX IVT Header | | + | Boot Data +--+ | + | CSF Pointer +--|-+ | + +---------------------------------+ | | | Signed Area + | Device Configuration Data (DCD) | | | | + +---------------------------------+ | | | + | Barebox Prebootloader (PBL) |<-+ | | + | Piggydata Hash (SHA256) +----|-+ | + +---------------------------------+ | | - + | Command Sequence File (CSF) |<---+ | + +---------------------------------+ | - + | Piggydata (Main Barebox Binary) |<-----+ | Hashed Area + +---------------------------------+ - + +In contrast to i.MX6, for the i.MX8MQ the piggydata can not be signed together +with the PBL binary. The DDR memory is initialized during the start of the PBL, +previous to this no access to the DDR memory is possible. Since the Tightly +Coupled Memory used for early startup on i.MX8MQ has only 256Kib, the whole +barebox can't be loaded and verified at once, since the complete barebox with +firmware has a size of ~500Kib. + +The bootrom loads the HDMI firmware unconditionally, since it is signed by NXP. +Afterwards the Prebootloader (PBL) is loaded into SRAM and the bootrom proceeds +to verify the PBL according to the Command Sequence File (CSF). The verified +PBL initializes the ARM Trusted Firmware (TF-A) and DDR RAM. It subsequently +loads the piggydata from the boot media and calculates the sha256sum of the +piggydata. This is compared to the sha256sum built into the PBL during compile +time, the PBL will only continue to boot if the sha256sum matches the builtin +sha256sum. + Using GPT on i.MX ^^^^^^^^^^^^^^^^^ diff --git a/Documentation/boards/imx/embest-marsboard.rst b/Documentation/boards/imx/embest-marsboard.rst new file mode 100644 index 0000000000..bdaa0880ae --- /dev/null +++ b/Documentation/boards/imx/embest-marsboard.rst @@ -0,0 +1,82 @@ +Embest MarS Board +================= + +Board comes with: + +* 1G DDR3 SDRAM +* 4G eMMC +* 2M SPI-NOR Flash + +Layout:: + + .-----------------------------------------------------. + |O OTG-->| V | O| + | SW1 USB '---' .--| + | .-----------. v.---. .->| <| + | | | 1|o--| O | `--| + | | i.MX6Dual | 2|--o| N Debug | + | | SoC | `---' USB | + | | | | + | `-----------' | + | | + | | + | | + | | + |O O| + `-----------------------------------------------------' + +Boot Configuration +================== + +DIP Switch ``SW1`` on the board can be used to set ``BOOT_MODE1`` and +``BOOT_MODE0`` going to the i.MX6: + +Set ``SW1 = 01`` for serial boot:: + + SW1 + v.---. + 1|o--| O + 2|--o| N + `---' + +Set ``SW1 = 10`` for internal (SPI-NOR Flash) boot:: + + SW1 + v.---. + 1|--o| O + 2|o--| N + `---' + +Set ``SW1 = 00`` for boot from eFuses:: + + SW1 + v.---. + 1|o--| O + 2|o--| N + `---' + +Flashing barebox +---------------- + + 1. Connect to the board's Debug Mini-USB (115200 8N1) + + 2. Set ``SW1 = 01`` for serial boot mode (see above) + + 3. Turn board's power on + + 4. Upload barebox image to the board via imx-usb-loader + +.. code-block:: none + + host$ imx-usb-loader images/barebox-embest-imx6q-marsboard.img +.. + + 4. Flash barebox to SPI-NOR Flash via Android Fastboot + +.. code-block:: none + + host$ fastboot flash bbu-spiflash images/barebox-embest-imx6q-marsboard.img + +.. + + 5. Restore ``SW1 = 10`` for internal (SPI-NOR) boot (see above) diff --git a/Documentation/boards/imx/zii-vf610-dev/openocd.cfg b/Documentation/boards/imx/zii-vf610-dev/openocd.cfg index 5127c7623d..c94f9d048d 100644 --- a/Documentation/boards/imx/zii-vf610-dev/openocd.cfg +++ b/Documentation/boards/imx/zii-vf610-dev/openocd.cfg @@ -148,10 +148,10 @@ proc ddr_init { } { mww phys 0x400ae210 0x00000506 ;# wm 32 DDRMC_CR132 0x00000506 mww phys 0x400ae224 0x00020000 ;# wm 32 DDRMC_CR137 0x00020000 mww phys 0x400ae228 0x01000100 ;# wm 32 DDRMC_CR138 0x01000100 - mww phys 0x400ae22c 0x04070303 ;# wm 32 DDRMC_CR154 0x682c4000 - mww phys 0x400ae230 0x00000040 ;# wm 32 DDRMC_CR155 0x00000009 - mww phys 0x400ae23c 0x06000080 ;# wm 32 DDRMC_CR158 0x00000006 - mww phys 0x400ae240 0x04070303 ;# wm 32 DDRMC_CR161 0x00010606 + mww phys 0x400ae268 0x682c4000 ;# wm 32 DDRMC_CR154 0x682c4000 + mww phys 0x400ae26c 0x00000009 ;# wm 32 DDRMC_CR155 0x00000009 + mww phys 0x400ae278 0x00000006 ;# wm 32 DDRMC_CR158 0x00000006 + mww phys 0x400ae284 0x00010606 ;# wm 32 DDRMC_CR161 0x00010606 # # flash-header-zii-vf610-dev.imxcfg diff --git a/Documentation/devicetree/index.rst b/Documentation/devicetree/index.rst index c6309defdf..908652642b 100644 --- a/Documentation/devicetree/index.rst +++ b/Documentation/devicetree/index.rst @@ -1,5 +1,60 @@ -Barebox specific devicetree bindings -==================================== +Barebox devicetree handling and bindings +======================================== + +The preferred way of adding board support to barebox is to have devices +on non-enumerable buses probed from device tree. +barebox imports the Linux OpenFirmware ``of_*``-API functions for device tree +parsing, which makes porting the device tree specific bits from device drivers +very straight forward. + +Additionally, barebox has support for programmatically fixing up device trees +it passes to the kernel, either directly via ``of_register_fixup`` or via device +tree overlays. + +Upstream Device Trees +--------------------- + +barebox regularly synchronizes with the Linux kernel device tree definitions +via the `kernel.org Split device-tree repository`_. +They are located under the top-level ``dts/`` directory. + +Patches against ``dts/`` and its subdirectories are not accepted upstream. + +.. _kernel.org Split device-tree repository: https://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git/ + +barebox Device Trees +-------------------- + +For supporting architectures, barebox device trees are located in +``arch/$ARCH/dts``. Usually the barebox ``board.dts`` imports the upstream +device tree under ``dts/src/$ARCH`` with ``#include "$ARCH/board.dts"`` and +then extends it with barebox-specifics like :ref:`barebox,state`, +environment or boot-time device configuration. + +Device Tree Compiler +-------------------- + +barebox makes use of the ``dtc`` and ``fdtget`` and the underlying ``libfdt`` +from the `Device-Tree Compiler`_ project. + +.. _Device-Tree Compiler: https://git.kernel.org/pub/scm/utils/dtc/dtc.git + +These utilities are built as part of the barebox build process. Additionally, +libfdt is compiled once more as part of the ``CONFIG_BOARD_ARM_GENERIC_DT`` +if selected. + +Steps to update ``scripts/dtc``: + +* Place a ``git-checkout`` of the upstream ``dtc`` directory in the parent + directory of your barebox ``git-checkout``. +* Run ``scripts/dtc/update-dtc-source.sh`` from the top-level barebox directory. +* Wait till ``dtc`` build, test, install and commit conclude. +* Compile-test with ``CONFIG_BOARD_ARM_GENERIC_DT=y``. +* If ``scripts/dtc/Makefile`` or barebox include file changes are necessary, + apply them manually in a commit preceding the ``dtc`` update. + +barebox-specific Bindings +------------------------- Contents: diff --git a/Documentation/user/barebox.rst b/Documentation/user/barebox.rst index c021a4c743..6bea883115 100644 --- a/Documentation/user/barebox.rst +++ b/Documentation/user/barebox.rst @@ -53,7 +53,6 @@ variable and the cross compiler with the ``CROSS_COMPILE`` environment variable. Currently, ``ARCH`` must be one of: * arm -* blackfin * mips * nios2 * openrisc |