[PATCH] doc: imx: habv4: Add Secure Boot guide for i.MX8M SPL targets
Add HABv4 documentation extension for SPL targets covering the following topics:
- How to sign an securely boot an flash.bin container image. - How to extend the root of trust for additional boot images. - Add SPL and fitImage CSF examples. - Add signature generation script example.
Signed-off-by: Marek Vasut marex@denx.de Cc: Breno Lima breno.lima@nxp.com Cc: Fabio Estevam festevam@denx.de Cc: Heiko Schocher hs@denx.de Cc: Peng Fan peng.fan@nxp.com Cc: Stefano Babic sbabic@denx.de Cc: Utkarsh Gupta utkarsh.gupta@nxp.com Cc: Ye Li ye.li@nxp.com --- doc/imx/habv4/csf_examples/mx8m/csf.sh | 77 +++++ doc/imx/habv4/csf_examples/mx8m/csf_fit.txt | 36 +++ doc/imx/habv4/csf_examples/mx8m/csf_spl.txt | 33 +++ doc/imx/habv4/guides/mx8m_spl_secure_boot.txt | 265 ++++++++++++++++++ 4 files changed, 411 insertions(+) create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf.sh create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_fit.txt create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_spl.txt create mode 100644 doc/imx/habv4/guides/mx8m_spl_secure_boot.txt
diff --git a/doc/imx/habv4/csf_examples/mx8m/csf.sh b/doc/imx/habv4/csf_examples/mx8m/csf.sh new file mode 100644 index 00000000000..6898513be51 --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf.sh @@ -0,0 +1,77 @@ +#!/bin/sh + +# 0) Generate keys +# +# WARNING: ECDSA keys are only supported by HAB 4.5 and newer (i.e. i.MX8M Plus) +# +# cd /path/to/cst-3.3.1/keys/ +# ./hab4_pki_tree.sh -existing-ca n -use-ecc n -kl 4096 -duration 10 -num-srk 4 -srk-ca y +# cd /path/to/cst-3.3.1/crts/ +# ../linux64/bin/srktool -h 4 -t SRK_1_2_3_4_table.bin -e SRK_1_2_3_4_fuse.bin -d sha256 -c ./SRK1_sha256_4096_65537_v3_ca_crt.pem,./SRK2_sha256_4096_65537_v3_ca_crt.pem,./SRK3_sha256_4096_65537_v3_ca_crt.pem,./SRK4_sha256_4096_65537_v3_ca_crt.pem -f 1 + +# 1) Build U-Boot (e.g. for i.MX8MM) +# +# export ATF_LOAD_ADDR=0x920000 +# cp -Lv /path/to/arm-trusted-firmware/build/imx8mm/release/bl31.bin . +# cp -Lv /path/to/firmware-imx-8.14/firmware/ddr/synopsys/ddr3* . +# make -j imx8mm_board_defconfig +# make -j`nproc` flash.bin + +# 2) Sign SPL and DRAM blobs + +cp doc/imx/habv4/csf_examples/mx8m/csf_spl.txt csf_spl.tmp +cp doc/imx/habv4/csf_examples/mx8m/csf_fit.txt csf_fit.tmp + +spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ s@.*=@@p" .config) - 0x40)) ) +spl_block_size=$(printf "0x%x" $(stat -tc %s u-boot-spl-ddr.bin)) +sed -i "/Blocks = / s@.*@ Blocks = $spl_block_base 0x0 $spl_block_size "flash.bin"@" csf_spl.tmp + +# Generate CSF blob +cst -i csf_spl.tmp -o csf_spl.bin + +# Patch CSF blob into flash.bin +spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@") +spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@") +spl_dd_offset=$((${spl_csf_offset} - ${spl_bin_offset} + 0x40)) +dd if=csf_spl.bin of=flash.bin bs=1 seek=${spl_dd_offset} conv=notrunc + +# 3) Sign u-boot.itb + +# fitImage tree +fit_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SYS_TEXT_BASE=/ s@.*=@@p" .config) - $(sed -n "/CONFIG_FIT_EXTERNAL_OFFSET=/ s@.*=@@p" .config) - 0x200 - 0x40)) ) +fit_block_offset=$(printf "0x%s" $(fdtget -t x u-boot.dtb /binman/imx-boot/uboot offset)) +fit_block_size=$(printf "0x%x" $(( ( $(fdtdump u-boot.itb 2>/dev/null | sed -n "/^...totalsize:/ s@.*(0x[0-9a-f]+).*@\1@p") + 0x1000 - 0x1 ) & ~(0x1000 - 0x1) + 0x20 )) ) +sed -i "/Blocks = / s@.*@ Blocks = $fit_block_base $fit_block_offset $fit_block_size "flash.bin", \\@" csf_fit.tmp + +# U-Boot +uboot_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot load)) +uboot_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot data-position)) + ${fit_block_offset} ))) +uboot_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot data-size)) +sed -i "/0xuuuu/ s@.*@ $uboot_block_base $uboot_block_offset $uboot_block_size "flash.bin", \\@" csf_fit.tmp + +# ATF +atf_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf load)) +atf_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf data-position)) + ${fit_block_offset} ))) +atf_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf data-size)) +sed -i "/0xaaaa/ s@.*@ $atf_block_base $atf_block_offset $atf_block_size "flash.bin", \\@" csf_fit.tmp + +# DTB +dtb_block_base=$(printf "0x%x" $(( ${uboot_block_base} + ${uboot_block_size} ))) +dtb_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-position)) + ${fit_block_offset} ))) +dtb_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-size)) +sed -i "/0xdddd/ s@.*@ $dtb_block_base $dtb_block_offset $dtb_block_size "flash.bin"@" csf_fit.tmp + +# IVT +ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} - 0x20 )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +csf_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20)) +csf_block_offset=$((${ivt_block_offset} + 0x20)) + +echo "0xd1002041 ${ivt_ptr_base} 0x00000000 0x00000000 0x00000000 ${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin +dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc + +# Generate CSF blob +cst -i csf_fit.tmp -o csf_fit.bin +# Patch CSF blob into flash.bin +dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} conv=notrunc diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt new file mode 100644 index 00000000000..cd1d4070a5e --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt @@ -0,0 +1,36 @@ +[Header] + Version = 4.3 + Hash Algorithm = sha256 + Engine = CAAM + Engine Configuration = 0 + Certificate Format = X509 + Signature Format = CMS + +[Install SRK] + # FIXME: Adjust path here + File = "/path/to/cst-3.3.1/crts/SRK_1_2_3_4_table.bin" + Source index = 0 + +[Install CSFK] + # FIXME: Adjust path here + File = "/path/to/cst-3.3.1/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem" + +[Authenticate CSF] + +[Install Key] + Verification index = 0 + Target Index = 2 + # FIXME: Adjust path here + File = "/path/to/cst-3.3.1/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem" + +[Authenticate Data] + Verification index = 2 + # FIXME: + # Line 1 -- fitImage tree + # Line 2 -- U-Boot u-boot-nodtb.bin blob + # Line 3 -- ATF BL31 blob + # Line 4 -- DT blob + Blocks = 0x401fcdc0 0x57c00 0xffff "flash.bin", \ + 0x40200000 0x62c00 0xuuuu "flash.bin", \ + 0x920000 0x00000 0xaaaa "flash.bin", \ + 0x40200000 0x00000 0xdddd "flash.bin" diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt new file mode 100644 index 00000000000..00e34f6b1b9 --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt @@ -0,0 +1,33 @@ +[Header] + Version = 4.3 + Hash Algorithm = sha256 + Engine = CAAM + Engine Configuration = 0 + Certificate Format = X509 + Signature Format = CMS + +[Install SRK] + # FIXME: Adjust path here + File = "/path/to/cst-3.3.1/crts/SRK_1_2_3_4_table.bin" + Source index = 0 + +[Install CSFK] + # FIXME: Adjust path here + File = "/path/to/cst-3.3.1/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem" + +[Authenticate CSF] + +[Unlock] + Engine = CAAM + Features = MID + +[Install Key] + Verification index = 0 + Target Index = 2 + # FIXME: Adjust path here + File = "/path/to/cst-3.3.1/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem" + +[Authenticate Data] + Verification index = 2 + # FIXME: Adjust start (first column) and size (third column) here + Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin" diff --git a/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt new file mode 100644 index 00000000000..747f7cd260f --- /dev/null +++ b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt @@ -0,0 +1,265 @@ + +=========================================================+ + + i.MX8M U-Boot HABv4 Secure Boot guide for SPL targets + + +=========================================================+ + +1. HABv4 secure boot process +----------------------------- + +This document is an addendum of mx6_mx7_spl_secure_boot.txt guide describing +a step-by-step procedure on how to sign and securely boot an U-Boot image for +SPL targets on i.MX8M, i.MX8M Mini, i.MX8M Nano, i.MX8M Plus. + +Details about HAB can be found in the application note AN4581[1] and in the +introduction_habv4.txt document. + +1.1 Building a SPL target supporting secure boot +------------------------------------------------- + +The U-Boot build for i.MX8M SoC makes use of Second Program Loader (SPL) +support, fitImage support and custom i.MX8M specific flash.bin container. +This leads to a generation of multiple intermediate build artifacts, the +U-Boot SPL, U-Boot binary, DT blob. These later two artifacts are bundled +with external ATF BL31 blob to form a fitImage. The fitImage is bundled +with SPL and external DDR and optional HDMI PHY initialization blobs to +form the final flash.bin container. The HABv4 can be used to authenticate +all of the input binaries separately. + +Out of reset the ROM code authenticates the SPL and PHY initialization +blobs, combination of which is responsible for initializing essential +features such as DDR, UART, PMIC and clock enablement. Once the DDR is +available, the SPL code loads the secondary fitImage to its specific +address and call the HAB APIs to extend the root of trust on its +components. + +The U-Boot SPL provides support to secure boot configuration and also +provide access to the HAB APIs exposed by the ROM vector table, the +U-Boot provides access to HAB APIs via SMC calls to ATF. The support +is enabled by selecting the CONFIG_IMX_HAB option. + +When built with this configuration the U-Boot correctly pads combined +SPL and PHY initialization blob image, called u-boot-spl-ddr.bin, by +aligning to the next 0xC00 address, so the CSF signature data generated +by CST can be concatenated to the image. + +The U-Boot also reserves space in the fitImage binary (u-boot.itb) between +the fitImage tree and external blobs included in it, so it can be used to +inject IVT and CST signatures used by SPL HAB calls to authenticate the +fitImage components. + +The diagram below illustrate a signed SPL combined with DDR PHY +initialization firmware blobs part of flash.bin container layout. +This part is loaded to memory address ( CONFIG_SPL_TEXT_BASE - 0x40 ) and +authenticated the BootROM. The reason for the offset is so that the *entry +would be at memory address CONFIG_SPL_TEXT_BASE when BootROM executes the +code within it: + + ------- +-----------------------------+ <-- *start + ^ | Image Vector Table | + | | (0x20 bytes) | + | +-----------------------------+ <-- *boot_data + | | Boot Data | + | +-----------------------------+ + | | Padding | + Signed | | to 0x40 bytes from *start | + Data | +-----------------------------+ <-- *entry + | | | + | | SPL combined with DDR PHY | + | | initialization blobs | + | | (u-boot-spl-ddr.bin) | + | | | + | +-----------------------------+ + v | Padding | + ------- +-----------------------------+ <-- *csf + | | + | Command Sequence File (CSF) | + | | + +-----------------------------+ + | Padding (optional) | + +-----------------------------+ + +The diagram below illustrate a signed U-Boot binary, DT blob and external +ATF BL31 blob combined to form fitImage part of flash.bin container layout. +The *load_address is derived from CONFIG_SYS_TEXT_BASE such that the U-Boot +binary *start is placed exactly at CONFIG_SPL_TEXT_BASE in DRAM, however the +SPL moves the fitImage tree further to location: + *load_address = CONFIG_SPL_TEXT_BASE - CONFIG_FIT_EXTERNAL_OFFSET (=12kiB) - + 512 Byte sector - sizeof(mkimage header) + + ------- +-----------------------------+ <-- *load_address + ^ | | + | | fitImage tree | + | | with external data at | + | | offset 12 kiB from tree | + | | (cca. 1 kiB) | + Signed | | | + .----- Tree | +-----------------------------+ + | Data | | Padding to next 4k aligned | + | | | from *load_address | + | | +-----------------------------+ <-- *ivt + | | | Image Vector Table | + | v | (0x20 bytes) | + | ------- +-----------------------------+ <-- *csf + | | Command Sequence File (CSF) | + | | for all signed entries in | + >--------------->| the fitImage, tree and data | + | | (cca 6-7 kiB) | + | +-----------------------------+ + | | Padding to 12 kiB offset | + | | from *load_address | + | ------- +-----------------------------+ <-- *start + | ^ | | + | Signed | | | + |---- Payload | | U-Boot external data blob | + | Data | | | + | v | | + | ------- +-----------------------------+ + | | Padding to 4 Bytes | + | ------- +-----------------------------+ + | ^ | | + | Signed | | | + |---- Payload | | ATF external data blob | + | Data | | | + | v | | + | ------- +-----------------------------+ + | | Padding to 4 Bytes | + | ------- +-----------------------------+ + | ^ | | + | Signed | | | + '---- Payload | | DTB external data blob | + Data | | | + v | | + ------- +-----------------------------+ + +The diagram below illustrate a combined flash.bin container layout: + + +-----------------------------+ + | Signed SPL part | + +-----------------------------+ + | Signed fitImage part | + +-----------------------------+ + +1.2 Enabling the secure boot support +------------------------------------- + +The first step is to generate an U-Boot image supporting the HAB features +mentioned above, this can be achieved by adding CONFIG_IMX_HAB to the +build configuration: + +- Defconfig: + + CONFIG_IMX_HAB=y + +- Kconfig: + + ARM architecture -> Support i.MX HAB features + +1.3 Signing the images +----------------------- + +The CSF contains all the commands that the HAB executes during the secure +boot. These commands instruct the HAB code on which memory areas of the image +to authenticate, which keys to install, use and etc. + +CSF examples are available under doc/imx/habv4/csf_examples/ directory. + +CSF "Blocks" line for csf_spl.txt can be generated as follows: + +``` +spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ s@.*=@@p" .config) - 0x40)) ) +spl_block_size=$(printf "0x%x" $(stat -tc %s u-boot-spl-ddr.bin)) +sed -i "/Blocks = / s@.*@ Blocks = $spl_block_base 0x0 $spl_block_size "flash.bin"@" csf_spl.txt +``` + +The resulting line looks as follows: +``` + Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin" +``` + +The columns mean: + - CONFIG_SPL_TEXT_BASE - 0x40 -- Start address of signed data, in DRAM + - 0x0 -- Start address of signed data, in "flash.bin" + - 0x306f0 -- Length of signed data, in "flash.bin" + - Filename -- "flash.bin" + +To generate signature for the SPL part of flash.bin container, use CST: +``` +cst -i csf_spl.tmp -o csf_spl.bin +``` + +The newly generated CST blob has to be patched into existing flash.bin +container. Conveniently, flash.bin IVT contains physical address of the +CSF blob. Remember, the SPL part of flash.bin container is loaded by the +BootROM at CONFIG_SPL_TEXT_BASE - 0x40 , so the offset of CSF blob in +the fitImage can be calculated and inserted into the flash.bin in the +correct location as follows: +``` +# offset = IVT_HEADER[6 = CSF address] - CONFIG_SPL_TEXT_BASE - 0x40 +spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@") +spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@") +spl_dd_offset=$((${spl_csf_offset} - ${spl_bin_offset} + 0x40)) +dd if=csf_spl.bin of=flash.bin bs=1 seek=${spl_dd_offset} conv=notrunc +``` + +CSF "Blocks" line for csf_fit.txt can be generated as follows: +``` +# fitImage tree +fit_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SYS_TEXT_BASE=/ s@.*=@@p" .config) - $(sed -n "/CONFIG_FIT_EXTERNAL_OFFSET=/ s@.*=@@p" .config) - 0x200 - 0x40)) ) +fit_block_offset=$(printf "0x%s" $(fdtget -t x u-boot.dtb /binman/imx-boot/uboot offset)) +fit_block_size=$(printf "0x%x" $(( ( $(fdtdump u-boot.itb 2>/dev/null | sed -n "/^...totalsize:/ s@.*(0x[0-9a-f]+).*@\1@p") + 0x1000 - 0x1 ) & ~(0x1000 - 0x1) + 0x20 )) ) +sed -i "/Blocks = / s@.*@ Blocks = $fit_block_base $fit_block_offset $fit_block_size "flash.bin", \\@" csf_fit.tmp + +# U-Boot +uboot_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot load)) +uboot_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot data-position)) + ${fit_block_offset} ))) +uboot_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot data-size)) +sed -i "/0xuuuu/ s@.*@ $uboot_block_base $uboot_block_offset $uboot_block_size "flash.bin", \\@" csf_fit.tmp + +# ATF +atf_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf load)) +atf_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf data-position)) + ${fit_block_offset} ))) +atf_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf data-size)) +sed -i "/0xaaaa/ s@.*@ $atf_block_base $atf_block_offset $atf_block_size "flash.bin", \\@" csf_fit.tmp + +# DTB +dtb_block_base=$(printf "0x%x" $(( ${uboot_block_base} + ${uboot_block_size} ))) +dtb_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-position)) + ${fit_block_offset} ))) +dtb_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-size)) +sed -i "/0xdddd/ s@.*@ $dtb_block_base $dtb_block_offset $dtb_block_size "flash.bin"@" csf_fit.tmp +``` + +The fitImage part of flash.bin requires separate IVT. Generate the IVT and +patch it into the correct aligned location of flash.bin as follows: +``` +# IVT +ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} - 0x20 )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +csf_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20)) +csf_block_offset=$((${ivt_block_offset} + 0x20)) + +echo "0xd1002041 ${ivt_ptr_base} 0x00000000 0x00000000 0x00000000 ${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin +dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc + +To generate CSF signature for the fitImage part of flash.bin container, use CST: +``` +cst -i csf_fit.tmp -o csf_fit.bin +``` + +Finally, patch the CSF signature into the fitImage right past the IVT: +``` +dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} conv=notrunc +``` + +The entire script is available in doc/imx/habv4/csf_examples/mx8m/csf.sh + +1.4 Closing the device +----------------------- + +The procedure for closing the device is similar as in Non-SPL targets, for a +complete procedure please refer to section "1.5 Programming SRK Hash" in +mx6_mx7_secure_boot.txt document available under doc/imx/habv4/guides/ +directory. + +References: +[1] AN4581: "Secure Boot on i.MX 50, i.MX 53, i.MX 6 and i.MX 7 Series using + HABv4" - Rev 2.
Hi Marek,
The Secure/Encrypted boot guides for 8M exist in NXP BSP at https://source.codeaurora.org/external/imx/uboot-imx/tree/doc/imx?h=lf_v2022 .04. Looks like they need to be up streamed. @Peng Fan/@Ye Li - FYI
Regards, Utkarsh G.
-----Original Message----- From: Marek Vasut marex@denx.de Sent: Tuesday, July 12, 2022 10:05 AM To: u-boot@lists.denx.de Cc: Marek Vasut marex@denx.de; Breno Matheus Lima breno.lima@nxp.com; Fabio Estevam festevam@denx.de; Heiko Schocher hs@denx.de; Peng Fan peng.fan@nxp.com; Stefano Babic sbabic@denx.de; Utkarsh Gupta utkarsh.gupta@nxp.com; Ye Li ye.li@nxp.com Subject: [EXT] [PATCH] doc: imx: habv4: Add Secure Boot guide for i.MX8M
SPL
targets
Caution: EXT Email
Add HABv4 documentation extension for SPL targets covering the following topics:
- How to sign an securely boot an flash.bin container image.
- How to extend the root of trust for additional boot images.
- Add SPL and fitImage CSF examples.
- Add signature generation script example.
Signed-off-by: Marek Vasut marex@denx.de Cc: Breno Lima breno.lima@nxp.com Cc: Fabio Estevam festevam@denx.de Cc: Heiko Schocher hs@denx.de Cc: Peng Fan peng.fan@nxp.com Cc: Stefano Babic sbabic@denx.de Cc: Utkarsh Gupta utkarsh.gupta@nxp.com Cc: Ye Li ye.li@nxp.com
doc/imx/habv4/csf_examples/mx8m/csf.sh | 77 +++++ doc/imx/habv4/csf_examples/mx8m/csf_fit.txt | 36 +++ doc/imx/habv4/csf_examples/mx8m/csf_spl.txt | 33 +++ doc/imx/habv4/guides/mx8m_spl_secure_boot.txt | 265 ++++++++++++++++++ 4 files changed, 411 insertions(+) create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf.sh create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_fit.txt create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_spl.txt create mode 100644 doc/imx/habv4/guides/mx8m_spl_secure_boot.txt
diff --git a/doc/imx/habv4/csf_examples/mx8m/csf.sh b/doc/imx/habv4/csf_examples/mx8m/csf.sh new file mode 100644 index 00000000000..6898513be51 --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf.sh @@ -0,0 +1,77 @@ +#!/bin/sh
+# 0) Generate keys +# +# WARNING: ECDSA keys are only supported by HAB 4.5 and newer (i.e. +i.MX8M Plus) # # cd /path/to/cst-3.3.1/keys/ +# ./hab4_pki_tree.sh -existing-ca n -use-ecc n -kl 4096 -duration 10
-num-srk
4 -srk-ca y +# cd /path/to/cst-3.3.1/crts/ +# ../linux64/bin/srktool -h 4 -t SRK_1_2_3_4_table.bin -e SRK_1_2_3_4_fuse.bin -d sha256 - c ./SRK1_sha256_4096_65537_v3_ca_crt.pem,./SRK2_sha256_4096_65537_v3_ ca_crt.pem,./SRK3_sha256_4096_65537_v3_ca_crt.pem,./SRK4_sha256_4096_ 65537_v3_ca_crt.pem -f 1
+# 1) Build U-Boot (e.g. for i.MX8MM) +# +# export ATF_LOAD_ADDR=0x920000 +# cp -Lv /path/to/arm-trusted-firmware/build/imx8mm/release/bl31.bin . +# cp -Lv /path/to/firmware-imx-8.14/firmware/ddr/synopsys/ddr3* . +# make -j imx8mm_board_defconfig +# make -j`nproc` flash.bin
+# 2) Sign SPL and DRAM blobs
+cp doc/imx/habv4/csf_examples/mx8m/csf_spl.txt csf_spl.tmp cp +doc/imx/habv4/csf_examples/mx8m/csf_fit.txt csf_fit.tmp
+spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ +s@.*=@@p" .config) - 0x40)) ) spl_block_size=$(printf "0x%x" $(stat -tc +%s u-boot-spl-ddr.bin)) sed -i "/Blocks = / s@.*@ Blocks = +$spl_block_base 0x0 $spl_block_size "flash.bin"@" csf_spl.tmp
+# Generate CSF blob +cst -i csf_spl.tmp -o csf_spl.bin
+# Patch CSF blob into flash.bin +spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed +"s@^@0x@") spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f +2 | sed "s@^@0x@") spl_dd_offset=$((${spl_csf_offset} - +${spl_bin_offset} + 0x40)) dd if=csf_spl.bin of=flash.bin bs=1 +seek=${spl_dd_offset} conv=notrunc
+# 3) Sign u-boot.itb
+# fitImage tree +fit_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SYS_TEXT_BASE=/ +s@.*=@@p" .config) - $(sed -n "/CONFIG_FIT_EXTERNAL_OFFSET=/ s@.*=@@p" +.config) - 0x200 - 0x40)) ) fit_block_offset=$(printf "0x%s" $(fdtget +-t x u-boot.dtb /binman/imx-boot/uboot offset)) fit_block_size=$(printf +"0x%x" $(( ( $(fdtdump u-boot.itb 2>/dev/null | sed -n +"/^...totalsize:/ s@.*(0x[0-9a-f]+).*@\1@p") + 0x1000 - 0x1 ) & +~(0x1000 - 0x1) + 0x20 )) ) sed -i "/Blocks = / s@.*@ Blocks = +$fit_block_base $fit_block_offset $fit_block_size "flash.bin", \\@" +csf_fit.tmp
+# U-Boot +uboot_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot +load)) uboot_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget +-t x u-boot.itb /images/uboot data-position)) + ${fit_block_offset} ))) uboot_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot
data-
size)) +sed -i "/0xuuuu/ s@.*@ $uboot_block_base $uboot_block_offset $uboot_block_size "flash.bin", \\@" csf_fit.tmp
+# ATF +atf_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf +load)) atf_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t +x u-boot.itb /images/atf data-position)) + ${fit_block_offset} ))) atf_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf
data-size))
+sed -i "/0xaaaa/ s@.*@ $atf_block_base $atf_block_offset $atf_block_size "flash.bin", \\@" csf_fit.tmp
+# DTB +dtb_block_base=$(printf "0x%x" $(( ${uboot_block_base} + +${uboot_block_size} ))) dtb_block_offset=$(printf "0x%x" $(( $(printf +"0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-position)) + ${fit_block_offset} ))) dtb_block_size=$(printf "0x%s" $(fdtget -t x
u-boot.itb
/images/fdt-1 data-size)) +sed -i "/0xdddd/ s@.*@ $dtb_block_base $dtb_block_offset $dtb_block_size "flash.bin"@" csf_fit.tmp
+# IVT +ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} - 0x20 )) | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +csf_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20)) +csf_block_offset=$((${ivt_block_offset} + 0x20))
+echo "0xd1002041 ${ivt_ptr_base} 0x00000000 0x00000000 0x00000000 +${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin +dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc
+# Generate CSF blob +cst -i csf_fit.tmp -o csf_fit.bin +# Patch CSF blob into flash.bin +dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} +conv=notrunc diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt new file mode 100644 index 00000000000..cd1d4070a5e --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt @@ -0,0 +1,36 @@ +[Header]
- Version = 4.3
- Hash Algorithm = sha256
- Engine = CAAM
- Engine Configuration = 0
- Certificate Format = X509
- Signature Format = CMS
+[Install SRK]
- # FIXME: Adjust path here
- File = "/path/to/cst-3.3.1/crts/SRK_1_2_3_4_table.bin"
- Source index = 0
+[Install CSFK]
- # FIXME: Adjust path here
- File =
"/path/to/cst-3.3.1/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate CSF]
+[Install Key]
- Verification index = 0
- Target Index = 2
- # FIXME: Adjust path here
- File = "/path/to/cst-
3.3.1/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate Data]
- Verification index = 2
- # FIXME:
- # Line 1 -- fitImage tree
- # Line 2 -- U-Boot u-boot-nodtb.bin blob
- # Line 3 -- ATF BL31 blob
- # Line 4 -- DT blob
- Blocks = 0x401fcdc0 0x57c00 0xffff "flash.bin", \
0x40200000 0x62c00 0xuuuu "flash.bin", \0x920000 0x00000 0xaaaa "flash.bin", \0x40200000 0x00000 0xdddd "flash.bin"diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt new file mode 100644 index 00000000000..00e34f6b1b9 --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt @@ -0,0 +1,33 @@ +[Header]
- Version = 4.3
- Hash Algorithm = sha256
- Engine = CAAM
- Engine Configuration = 0
- Certificate Format = X509
- Signature Format = CMS
+[Install SRK]
- # FIXME: Adjust path here
- File = "/path/to/cst-3.3.1/crts/SRK_1_2_3_4_table.bin"
- Source index = 0
+[Install CSFK]
- # FIXME: Adjust path here
- File =
"/path/to/cst-3.3.1/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate CSF]
+[Unlock]
- Engine = CAAM
- Features = MID
+[Install Key]
- Verification index = 0
- Target Index = 2
- # FIXME: Adjust path here
- File = "/path/to/cst-
3.3.1/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate Data]
- Verification index = 2
- # FIXME: Adjust start (first column) and size (third column) here
- Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin"
diff --git a/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt new file mode 100644 index 00000000000..747f7cd260f --- /dev/null +++ b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt @@ -0,0 +1,265 @@
+=========================================================++ i.MX8M U-Boot HABv4 Secure Boot guide for SPL targets ++=========================================================++1. HABv4 secure boot process +-----------------------------
+This document is an addendum of mx6_mx7_spl_secure_boot.txt guide +describing a step-by-step procedure on how to sign and securely boot an +U-Boot image for SPL targets on i.MX8M, i.MX8M Mini, i.MX8M Nano, i.MX8M Plus.
+Details about HAB can be found in the application note AN4581[1] and in +the introduction_habv4.txt document.
+1.1 Building a SPL target supporting secure boot +-------------------------------------------------
+The U-Boot build for i.MX8M SoC makes use of Second Program Loader +(SPL) support, fitImage support and custom i.MX8M specific flash.bin
container.
+This leads to a generation of multiple intermediate build artifacts, +the U-Boot SPL, U-Boot binary, DT blob. These later two artifacts are +bundled with external ATF BL31 blob to form a fitImage. The fitImage is +bundled with SPL and external DDR and optional HDMI PHY initialization +blobs to form the final flash.bin container. The HABv4 can be used to +authenticate all of the input binaries separately.
+Out of reset the ROM code authenticates the SPL and PHY initialization +blobs, combination of which is responsible for initializing essential +features such as DDR, UART, PMIC and clock enablement. Once the DDR is +available, the SPL code loads the secondary fitImage to its specific +address and call the HAB APIs to extend the root of trust on its +components.
+The U-Boot SPL provides support to secure boot configuration and also +provide access to the HAB APIs exposed by the ROM vector table, the +U-Boot provides access to HAB APIs via SMC calls to ATF. The support is +enabled by selecting the CONFIG_IMX_HAB option.
+When built with this configuration the U-Boot correctly pads combined +SPL and PHY initialization blob image, called u-boot-spl-ddr.bin, by +aligning to the next 0xC00 address, so the CSF signature data generated +by CST can be concatenated to the image.
+The U-Boot also reserves space in the fitImage binary (u-boot.itb) +between the fitImage tree and external blobs included in it, so it can +be used to inject IVT and CST signatures used by SPL HAB calls to +authenticate the fitImage components.
+The diagram below illustrate a signed SPL combined with DDR PHY +initialization firmware blobs part of flash.bin container layout. +This part is loaded to memory address ( CONFIG_SPL_TEXT_BASE - 0x40 ) +and authenticated the BootROM. The reason for the offset is so that the +*entry would be at memory address CONFIG_SPL_TEXT_BASE when BootROM +executes the code within it:
------- +-----------------------------+ <-- *start^ | Image Vector Table || | (0x20 bytes) || +-----------------------------+ <-- *boot_data| | Boot Data || +-----------------------------+| | Padding |Signed | | to 0x40 bytes from *start |Data | +-----------------------------+ <-- *entry| | || | SPL combined with DDR PHY || | initialization blobs || | (u-boot-spl-ddr.bin) || | || +-----------------------------+v | Padding |------- +-----------------------------+ <-- *csf| || Command Sequence File (CSF) || |+-----------------------------+| Padding (optional) |+-----------------------------++The diagram below illustrate a signed U-Boot binary, DT blob and +external ATF BL31 blob combined to form fitImage part of flash.bin
container
layout. +The *load_address is derived from CONFIG_SYS_TEXT_BASE such that the +U-Boot binary *start is placed exactly at CONFIG_SPL_TEXT_BASE in DRAM, +however the SPL moves the fitImage tree further to location:
- *load_address = CONFIG_SPL_TEXT_BASE - CONFIG_FIT_EXTERNAL_OFFSET
(=12kiB) -
512 Byte sector - sizeof(mkimage header)------- +-----------------------------+ <-- *load_address^ | || | fitImage tree || | with external data at || | offset 12 kiB from tree || | (cca. 1 kiB) |Signed | | |- .----- Tree | +-----------------------------+
- | Data | | Padding to next 4k aligned |
- | | | from *load_address |
- | | +-----------------------------+ <-- *ivt
- | | | Image Vector Table |
- | v | (0x20 bytes) |
- | ------- +-----------------------------+ <-- *csf
- | | Command Sequence File (CSF) |
- | | for all signed entries in |
- | | (cca 6-7 kiB) |
- | +-----------------------------+
- | | Padding to 12 kiB offset |
- | | from *load_address |
- | ------- +-----------------------------+ <-- *start
- | ^ | |
- | Signed | | |
- |---- Payload | | U-Boot external data blob |
- | Data | | |
- | v | |
- | ------- +-----------------------------+
- | | Padding to 4 Bytes |
- | ------- +-----------------------------+
- | ^ | |
- | Signed | | |
- |---- Payload | | ATF external data blob |
- | Data | | |
- | v | |
- | ------- +-----------------------------+
- | | Padding to 4 Bytes |
- | ------- +-----------------------------+
- | ^ | |
- | Signed | | |
- '---- Payload | | DTB external data blob |
Data | | |v | |------- +-----------------------------++The diagram below illustrate a combined flash.bin container layout:
+-----------------------------+| Signed SPL part |+-----------------------------+| Signed fitImage part |+-----------------------------++1.2 Enabling the secure boot support +-------------------------------------
+The first step is to generate an U-Boot image supporting the HAB +features mentioned above, this can be achieved by adding CONFIG_IMX_HAB +to the build configuration:
+- Defconfig:
- CONFIG_IMX_HAB=y
+- Kconfig:
- ARM architecture -> Support i.MX HAB features
+1.3 Signing the images +-----------------------
+The CSF contains all the commands that the HAB executes during the +secure boot. These commands instruct the HAB code on which memory areas +of the image to authenticate, which keys to install, use and etc.
+CSF examples are available under doc/imx/habv4/csf_examples/ directory.
+CSF "Blocks" line for csf_spl.txt can be generated as follows:
+``` +spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ +s@.*=@@p" .config) - 0x40)) ) spl_block_size=$(printf "0x%x" $(stat -tc +%s u-boot-spl-ddr.bin)) sed -i "/Blocks = / s@.*@ Blocks = +$spl_block_base 0x0 $spl_block_size "flash.bin"@" csf_spl.txt ```
+The resulting line looks as follows: +```
- Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin"
+```
+The columns mean:
- CONFIG_SPL_TEXT_BASE - 0x40 -- Start address of signed data, in
+DRAM
- 0x0 -- Start address of signed data, in "flash.bin"
- 0x306f0 -- Length of signed data, in "flash.bin"
- Filename -- "flash.bin"
+To generate signature for the SPL part of flash.bin container, use CST: +``` +cst -i csf_spl.tmp -o csf_spl.bin +```
+The newly generated CST blob has to be patched into existing flash.bin +container. Conveniently, flash.bin IVT contains physical address of the +CSF blob. Remember, the SPL part of flash.bin container is loaded by +the BootROM at CONFIG_SPL_TEXT_BASE - 0x40 , so the offset of CSF blob +in the fitImage can be calculated and inserted into the flash.bin in +the correct location as follows: +``` +# offset = IVT_HEADER[6 = CSF address] - CONFIG_SPL_TEXT_BASE - 0x40 +spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed +"s@^@0x@") spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f +2 | sed "s@^@0x@") spl_dd_offset=$((${spl_csf_offset} - +${spl_bin_offset} + 0x40)) dd if=csf_spl.bin of=flash.bin bs=1 +seek=${spl_dd_offset} conv=notrunc ```
+CSF "Blocks" line for csf_fit.txt can be generated as follows: +``` +# fitImage tree +fit_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SYS_TEXT_BASE=/ +s@.*=@@p" .config) - $(sed -n "/CONFIG_FIT_EXTERNAL_OFFSET=/ s@.*=@@p" +.config) - 0x200 - 0x40)) ) fit_block_offset=$(printf "0x%s" $(fdtget +-t x u-boot.dtb /binman/imx-boot/uboot offset)) fit_block_size=$(printf +"0x%x" $(( ( $(fdtdump u-boot.itb 2>/dev/null | sed -n +"/^...totalsize:/ s@.*(0x[0-9a-f]+).*@\1@p") + 0x1000 - 0x1 ) & +~(0x1000 - 0x1) + 0x20 )) ) sed -i "/Blocks = / s@.*@ Blocks = +$fit_block_base $fit_block_offset $fit_block_size "flash.bin", \\@" +csf_fit.tmp
+# U-Boot +uboot_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot +load)) uboot_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget +-t x u-boot.itb /images/uboot data-position)) + ${fit_block_offset} ))) uboot_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot
data-
size)) +sed -i "/0xuuuu/ s@.*@ $uboot_block_base $uboot_block_offset $uboot_block_size "flash.bin", \\@" csf_fit.tmp
+# ATF +atf_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf +load)) atf_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t +x u-boot.itb /images/atf data-position)) + ${fit_block_offset} ))) atf_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf
data-size))
+sed -i "/0xaaaa/ s@.*@ $atf_block_base $atf_block_offset $atf_block_size "flash.bin", \\@" csf_fit.tmp
+# DTB +dtb_block_base=$(printf "0x%x" $(( ${uboot_block_base} + +${uboot_block_size} ))) dtb_block_offset=$(printf "0x%x" $(( $(printf +"0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-position)) + ${fit_block_offset} ))) dtb_block_size=$(printf "0x%s" $(fdtget -t x
u-boot.itb
/images/fdt-1 data-size)) +sed -i "/0xdddd/ s@.*@ $dtb_block_base $dtb_block_offset $dtb_block_size "flash.bin"@" csf_fit.tmp +```
+The fitImage part of flash.bin requires separate IVT. Generate the IVT +and patch it into the correct aligned location of flash.bin as follows: +``` +# IVT +ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} - 0x20 )) | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +csf_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20)) +csf_block_offset=$((${ivt_block_offset} + 0x20))
+echo "0xd1002041 ${ivt_ptr_base} 0x00000000 0x00000000 0x00000000 +${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin +dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc
+To generate CSF signature for the fitImage part of flash.bin container,
use CST:
+``` +cst -i csf_fit.tmp -o csf_fit.bin +```
+Finally, patch the CSF signature into the fitImage right past the IVT: +``` +dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} +conv=notrunc ```
+The entire script is available in +doc/imx/habv4/csf_examples/mx8m/csf.sh
+1.4 Closing the device +-----------------------
+The procedure for closing the device is similar as in Non-SPL targets, +for a complete procedure please refer to section "1.5 Programming SRK +Hash" in mx6_mx7_secure_boot.txt document available under +doc/imx/habv4/guides/ directory.
+References: +[1] AN4581: "Secure Boot on i.MX 50, i.MX 53, i.MX 6 and i.MX 7 Series
+using HABv4" - Rev 2.
2.35.1
On 7/13/22 00:57, Utkarsh Gupta wrote:
Hi Marek,
The Secure/Encrypted boot guides for 8M exist in NXP BSP at https://source.codeaurora.org/external/imx/uboot-imx/tree/doc/imx?h=lf_v2022 .04. Looks like they need to be up streamed. @Peng Fan/@Ye Li - FYI
Regards, Utkarsh G.
-----Original Message----- From: Marek Vasut marex@denx.de Sent: Tuesday, July 12, 2022 10:05 AM To: u-boot@lists.denx.de Cc: Marek Vasut marex@denx.de; Breno Matheus Lima breno.lima@nxp.com; Fabio Estevam festevam@denx.de; Heiko Schocher hs@denx.de; Peng Fan peng.fan@nxp.com; Stefano Babic sbabic@denx.de; Utkarsh Gupta utkarsh.gupta@nxp.com; Ye Li ye.li@nxp.com Subject: [EXT] [PATCH] doc: imx: habv4: Add Secure Boot guide for i.MX8M
SPL
targets
Caution: EXT Email
Add HABv4 documentation extension for SPL targets covering the following topics:
- How to sign an securely boot an flash.bin container image.
- How to extend the root of trust for additional boot images.
- Add SPL and fitImage CSF examples.
- Add signature generation script example.
Signed-off-by: Marek Vasut marex@denx.de Cc: Breno Lima breno.lima@nxp.com Cc: Fabio Estevam festevam@denx.de Cc: Heiko Schocher hs@denx.de Cc: Peng Fan peng.fan@nxp.com Cc: Stefano Babic sbabic@denx.de Cc: Utkarsh Gupta utkarsh.gupta@nxp.com Cc: Ye Li ye.li@nxp.com
doc/imx/habv4/csf_examples/mx8m/csf.sh | 77 +++++ doc/imx/habv4/csf_examples/mx8m/csf_fit.txt | 36 +++ doc/imx/habv4/csf_examples/mx8m/csf_spl.txt | 33 +++ doc/imx/habv4/guides/mx8m_spl_secure_boot.txt | 265 ++++++++++++++++++ 4 files changed, 411 insertions(+) create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf.sh create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_fit.txt create mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_spl.txt create mode 100644 doc/imx/habv4/guides/mx8m_spl_secure_boot.txt
diff --git a/doc/imx/habv4/csf_examples/mx8m/csf.sh b/doc/imx/habv4/csf_examples/mx8m/csf.sh new file mode 100644 index 00000000000..6898513be51 --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf.sh @@ -0,0 +1,77 @@ +#!/bin/sh
+# 0) Generate keys +# +# WARNING: ECDSA keys are only supported by HAB 4.5 and newer (i.e. +i.MX8M Plus) # # cd /path/to/cst-3.3.1/keys/ +# ./hab4_pki_tree.sh -existing-ca n -use-ecc n -kl 4096 -duration 10
-num-srk
4 -srk-ca y +# cd /path/to/cst-3.3.1/crts/ +# ../linux64/bin/srktool -h 4 -t SRK_1_2_3_4_table.bin -e SRK_1_2_3_4_fuse.bin -d sha256 - c ./SRK1_sha256_4096_65537_v3_ca_crt.pem,./SRK2_sha256_4096_65537_v3_ ca_crt.pem,./SRK3_sha256_4096_65537_v3_ca_crt.pem,./SRK4_sha256_4096_ 65537_v3_ca_crt.pem -f 1
+# 1) Build U-Boot (e.g. for i.MX8MM) +# +# export ATF_LOAD_ADDR=0x920000 +# cp -Lv /path/to/arm-trusted-firmware/build/imx8mm/release/bl31.bin . +# cp -Lv /path/to/firmware-imx-8.14/firmware/ddr/synopsys/ddr3* . +# make -j imx8mm_board_defconfig +# make -j`nproc` flash.bin
+# 2) Sign SPL and DRAM blobs
+cp doc/imx/habv4/csf_examples/mx8m/csf_spl.txt csf_spl.tmp cp +doc/imx/habv4/csf_examples/mx8m/csf_fit.txt csf_fit.tmp
+spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ +s@.*=@@p" .config) - 0x40)) ) spl_block_size=$(printf "0x%x" $(stat -tc +%s u-boot-spl-ddr.bin)) sed -i "/Blocks = / s@.*@ Blocks = +$spl_block_base 0x0 $spl_block_size "flash.bin"@" csf_spl.tmp
+# Generate CSF blob +cst -i csf_spl.tmp -o csf_spl.bin
+# Patch CSF blob into flash.bin +spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed +"s@^@0x@") spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f +2 | sed "s@^@0x@") spl_dd_offset=$((${spl_csf_offset} - +${spl_bin_offset} + 0x40)) dd if=csf_spl.bin of=flash.bin bs=1 +seek=${spl_dd_offset} conv=notrunc
+# 3) Sign u-boot.itb
+# fitImage tree +fit_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SYS_TEXT_BASE=/ +s@.*=@@p" .config) - $(sed -n "/CONFIG_FIT_EXTERNAL_OFFSET=/ s@.*=@@p" +.config) - 0x200 - 0x40)) ) fit_block_offset=$(printf "0x%s" $(fdtget +-t x u-boot.dtb /binman/imx-boot/uboot offset)) fit_block_size=$(printf +"0x%x" $(( ( $(fdtdump u-boot.itb 2>/dev/null | sed -n +"/^...totalsize:/ s@.*(0x[0-9a-f]+).*@\1@p") + 0x1000 - 0x1 ) & +~(0x1000 - 0x1) + 0x20 )) ) sed -i "/Blocks = / s@.*@ Blocks = +$fit_block_base $fit_block_offset $fit_block_size "flash.bin", \\@" +csf_fit.tmp
+# U-Boot +uboot_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot +load)) uboot_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget +-t x u-boot.itb /images/uboot data-position)) + ${fit_block_offset} ))) uboot_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot
data-
size)) +sed -i "/0xuuuu/ s@.*@ $uboot_block_base $uboot_block_offset $uboot_block_size "flash.bin", \\@" csf_fit.tmp
+# ATF +atf_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf +load)) atf_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t +x u-boot.itb /images/atf data-position)) + ${fit_block_offset} ))) atf_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf
data-size))
+sed -i "/0xaaaa/ s@.*@ $atf_block_base $atf_block_offset $atf_block_size "flash.bin", \\@" csf_fit.tmp
+# DTB +dtb_block_base=$(printf "0x%x" $(( ${uboot_block_base} + +${uboot_block_size} ))) dtb_block_offset=$(printf "0x%x" $(( $(printf +"0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-position)) + ${fit_block_offset} ))) dtb_block_size=$(printf "0x%s" $(fdtget -t x
u-boot.itb
/images/fdt-1 data-size)) +sed -i "/0xdddd/ s@.*@ $dtb_block_base $dtb_block_offset $dtb_block_size "flash.bin"@" csf_fit.tmp
+# IVT +ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} - 0x20 )) | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +csf_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20)) +csf_block_offset=$((${ivt_block_offset} + 0x20))
+echo "0xd1002041 ${ivt_ptr_base} 0x00000000 0x00000000 0x00000000 +${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin +dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc
+# Generate CSF blob +cst -i csf_fit.tmp -o csf_fit.bin +# Patch CSF blob into flash.bin +dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} +conv=notrunc diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt new file mode 100644 index 00000000000..cd1d4070a5e --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt @@ -0,0 +1,36 @@ +[Header]
- Version = 4.3
- Hash Algorithm = sha256
- Engine = CAAM
- Engine Configuration = 0
- Certificate Format = X509
- Signature Format = CMS
+[Install SRK]
- # FIXME: Adjust path here
- File = "/path/to/cst-3.3.1/crts/SRK_1_2_3_4_table.bin"
- Source index = 0
+[Install CSFK]
- # FIXME: Adjust path here
- File =
"/path/to/cst-3.3.1/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate CSF]
+[Install Key]
- Verification index = 0
- Target Index = 2
- # FIXME: Adjust path here
- File = "/path/to/cst-
3.3.1/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate Data]
- Verification index = 2
- # FIXME:
- # Line 1 -- fitImage tree
- # Line 2 -- U-Boot u-boot-nodtb.bin blob
- # Line 3 -- ATF BL31 blob
- # Line 4 -- DT blob
- Blocks = 0x401fcdc0 0x57c00 0xffff "flash.bin", \
0x40200000 0x62c00 0xuuuu "flash.bin", \0x920000 0x00000 0xaaaa "flash.bin", \0x40200000 0x00000 0xdddd "flash.bin"diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt new file mode 100644 index 00000000000..00e34f6b1b9 --- /dev/null +++ b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt @@ -0,0 +1,33 @@ +[Header]
- Version = 4.3
- Hash Algorithm = sha256
- Engine = CAAM
- Engine Configuration = 0
- Certificate Format = X509
- Signature Format = CMS
+[Install SRK]
- # FIXME: Adjust path here
- File = "/path/to/cst-3.3.1/crts/SRK_1_2_3_4_table.bin"
- Source index = 0
+[Install CSFK]
- # FIXME: Adjust path here
- File =
"/path/to/cst-3.3.1/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate CSF]
+[Unlock]
- Engine = CAAM
- Features = MID
+[Install Key]
- Verification index = 0
- Target Index = 2
- # FIXME: Adjust path here
- File = "/path/to/cst-
3.3.1/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem"
+[Authenticate Data]
- Verification index = 2
- # FIXME: Adjust start (first column) and size (third column) here
- Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin"
diff --git a/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt new file mode 100644 index 00000000000..747f7cd260f --- /dev/null +++ b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt @@ -0,0 +1,265 @@
+=========================================================++ i.MX8M U-Boot HABv4 Secure Boot guide for SPL targets ++=========================================================++1. HABv4 secure boot process +-----------------------------
+This document is an addendum of mx6_mx7_spl_secure_boot.txt guide +describing a step-by-step procedure on how to sign and securely boot an +U-Boot image for SPL targets on i.MX8M, i.MX8M Mini, i.MX8M Nano, i.MX8M Plus.
+Details about HAB can be found in the application note AN4581[1] and in +the introduction_habv4.txt document.
+1.1 Building a SPL target supporting secure boot +-------------------------------------------------
+The U-Boot build for i.MX8M SoC makes use of Second Program Loader +(SPL) support, fitImage support and custom i.MX8M specific flash.bin
container.
+This leads to a generation of multiple intermediate build artifacts, +the U-Boot SPL, U-Boot binary, DT blob. These later two artifacts are +bundled with external ATF BL31 blob to form a fitImage. The fitImage is +bundled with SPL and external DDR and optional HDMI PHY initialization +blobs to form the final flash.bin container. The HABv4 can be used to +authenticate all of the input binaries separately.
+Out of reset the ROM code authenticates the SPL and PHY initialization +blobs, combination of which is responsible for initializing essential +features such as DDR, UART, PMIC and clock enablement. Once the DDR is +available, the SPL code loads the secondary fitImage to its specific +address and call the HAB APIs to extend the root of trust on its +components.
+The U-Boot SPL provides support to secure boot configuration and also +provide access to the HAB APIs exposed by the ROM vector table, the +U-Boot provides access to HAB APIs via SMC calls to ATF. The support is +enabled by selecting the CONFIG_IMX_HAB option.
+When built with this configuration the U-Boot correctly pads combined +SPL and PHY initialization blob image, called u-boot-spl-ddr.bin, by +aligning to the next 0xC00 address, so the CSF signature data generated +by CST can be concatenated to the image.
+The U-Boot also reserves space in the fitImage binary (u-boot.itb) +between the fitImage tree and external blobs included in it, so it can +be used to inject IVT and CST signatures used by SPL HAB calls to +authenticate the fitImage components.
+The diagram below illustrate a signed SPL combined with DDR PHY +initialization firmware blobs part of flash.bin container layout. +This part is loaded to memory address ( CONFIG_SPL_TEXT_BASE - 0x40 ) +and authenticated the BootROM. The reason for the offset is so that the +*entry would be at memory address CONFIG_SPL_TEXT_BASE when BootROM +executes the code within it:
------- +-----------------------------+ <-- *start^ | Image Vector Table || | (0x20 bytes) || +-----------------------------+ <-- *boot_data| | Boot Data || +-----------------------------+| | Padding |Signed | | to 0x40 bytes from *start |Data | +-----------------------------+ <-- *entry| | || | SPL combined with DDR PHY || | initialization blobs || | (u-boot-spl-ddr.bin) || | || +-----------------------------+v | Padding |------- +-----------------------------+ <-- *csf| || Command Sequence File (CSF) || |+-----------------------------+| Padding (optional) |+-----------------------------++The diagram below illustrate a signed U-Boot binary, DT blob and +external ATF BL31 blob combined to form fitImage part of flash.bin
container
layout. +The *load_address is derived from CONFIG_SYS_TEXT_BASE such that the +U-Boot binary *start is placed exactly at CONFIG_SPL_TEXT_BASE in DRAM, +however the SPL moves the fitImage tree further to location:
- *load_address = CONFIG_SPL_TEXT_BASE - CONFIG_FIT_EXTERNAL_OFFSET
(=12kiB) -
512 Byte sector - sizeof(mkimage header)------- +-----------------------------+ <-- *load_address^ | || | fitImage tree || | with external data at || | offset 12 kiB from tree || | (cca. 1 kiB) |Signed | | |- .----- Tree | +-----------------------------+
- | Data | | Padding to next 4k aligned |
- | | | from *load_address |
- | | +-----------------------------+ <-- *ivt
- | | | Image Vector Table |
- | v | (0x20 bytes) |
- | ------- +-----------------------------+ <-- *csf
- | | Command Sequence File (CSF) |
- | | for all signed entries in |
- | | (cca 6-7 kiB) |
- | +-----------------------------+
- | | Padding to 12 kiB offset |
- | | from *load_address |
- | ------- +-----------------------------+ <-- *start
- | ^ | |
- | Signed | | |
- |---- Payload | | U-Boot external data blob |
- | Data | | |
- | v | |
- | ------- +-----------------------------+
- | | Padding to 4 Bytes |
- | ------- +-----------------------------+
- | ^ | |
- | Signed | | |
- |---- Payload | | ATF external data blob |
- | Data | | |
- | v | |
- | ------- +-----------------------------+
- | | Padding to 4 Bytes |
- | ------- +-----------------------------+
- | ^ | |
- | Signed | | |
- '---- Payload | | DTB external data blob |
Data | | |v | |------- +-----------------------------++The diagram below illustrate a combined flash.bin container layout:
+-----------------------------+| Signed SPL part |+-----------------------------+| Signed fitImage part |+-----------------------------++1.2 Enabling the secure boot support +-------------------------------------
+The first step is to generate an U-Boot image supporting the HAB +features mentioned above, this can be achieved by adding CONFIG_IMX_HAB +to the build configuration:
+- Defconfig:
- CONFIG_IMX_HAB=y
+- Kconfig:
- ARM architecture -> Support i.MX HAB features
+1.3 Signing the images +-----------------------
+The CSF contains all the commands that the HAB executes during the +secure boot. These commands instruct the HAB code on which memory areas +of the image to authenticate, which keys to install, use and etc.
+CSF examples are available under doc/imx/habv4/csf_examples/ directory.
+CSF "Blocks" line for csf_spl.txt can be generated as follows:
+``` +spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ +s@.*=@@p" .config) - 0x40)) ) spl_block_size=$(printf "0x%x" $(stat -tc +%s u-boot-spl-ddr.bin)) sed -i "/Blocks = / s@.*@ Blocks = +$spl_block_base 0x0 $spl_block_size "flash.bin"@" csf_spl.txt ```
+The resulting line looks as follows: +```
- Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin"
+```
+The columns mean:
- CONFIG_SPL_TEXT_BASE - 0x40 -- Start address of signed data, in
+DRAM
- 0x0 -- Start address of signed data, in "flash.bin"
- 0x306f0 -- Length of signed data, in "flash.bin"
- Filename -- "flash.bin"
+To generate signature for the SPL part of flash.bin container, use CST: +``` +cst -i csf_spl.tmp -o csf_spl.bin +```
+The newly generated CST blob has to be patched into existing flash.bin +container. Conveniently, flash.bin IVT contains physical address of the +CSF blob. Remember, the SPL part of flash.bin container is loaded by +the BootROM at CONFIG_SPL_TEXT_BASE - 0x40 , so the offset of CSF blob +in the fitImage can be calculated and inserted into the flash.bin in +the correct location as follows: +``` +# offset = IVT_HEADER[6 = CSF address] - CONFIG_SPL_TEXT_BASE - 0x40 +spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed +"s@^@0x@") spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f +2 | sed "s@^@0x@") spl_dd_offset=$((${spl_csf_offset} - +${spl_bin_offset} + 0x40)) dd if=csf_spl.bin of=flash.bin bs=1 +seek=${spl_dd_offset} conv=notrunc ```
+CSF "Blocks" line for csf_fit.txt can be generated as follows: +``` +# fitImage tree +fit_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SYS_TEXT_BASE=/ +s@.*=@@p" .config) - $(sed -n "/CONFIG_FIT_EXTERNAL_OFFSET=/ s@.*=@@p" +.config) - 0x200 - 0x40)) ) fit_block_offset=$(printf "0x%s" $(fdtget +-t x u-boot.dtb /binman/imx-boot/uboot offset)) fit_block_size=$(printf +"0x%x" $(( ( $(fdtdump u-boot.itb 2>/dev/null | sed -n +"/^...totalsize:/ s@.*(0x[0-9a-f]+).*@\1@p") + 0x1000 - 0x1 ) & +~(0x1000 - 0x1) + 0x20 )) ) sed -i "/Blocks = / s@.*@ Blocks = +$fit_block_base $fit_block_offset $fit_block_size "flash.bin", \\@" +csf_fit.tmp
+# U-Boot +uboot_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot +load)) uboot_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget +-t x u-boot.itb /images/uboot data-position)) + ${fit_block_offset} ))) uboot_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/uboot
data-
size)) +sed -i "/0xuuuu/ s@.*@ $uboot_block_base $uboot_block_offset $uboot_block_size "flash.bin", \\@" csf_fit.tmp
+# ATF +atf_block_base=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf +load)) atf_block_offset=$(printf "0x%x" $(( $(printf "0x%s" $(fdtget -t +x u-boot.itb /images/atf data-position)) + ${fit_block_offset} ))) atf_block_size=$(printf "0x%s" $(fdtget -t x u-boot.itb /images/atf
data-size))
+sed -i "/0xaaaa/ s@.*@ $atf_block_base $atf_block_offset $atf_block_size "flash.bin", \\@" csf_fit.tmp
+# DTB +dtb_block_base=$(printf "0x%x" $(( ${uboot_block_base} + +${uboot_block_size} ))) dtb_block_offset=$(printf "0x%x" $(( $(printf +"0x%s" $(fdtget -t x u-boot.itb /images/fdt-1 data-position)) + ${fit_block_offset} ))) dtb_block_size=$(printf "0x%s" $(fdtget -t x
u-boot.itb
/images/fdt-1 data-size)) +sed -i "/0xdddd/ s@.*@ $dtb_block_base $dtb_block_offset $dtb_block_size "flash.bin"@" csf_fit.tmp +```
+The fitImage part of flash.bin requires separate IVT. Generate the IVT +and patch it into the correct aligned location of flash.bin as follows: +``` +# IVT +ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} - 0x20 )) | sed +"s@(..)(..)(..)(..)@0x\4\3\2\1@") +csf_block_base=$(printf "%08x" $(( ${fit_block_base} + +${fit_block_size} )) | sed "s@(..)(..)(..)(..)@0x\4\3\2\1@") +ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20)) +csf_block_offset=$((${ivt_block_offset} + 0x20))
+echo "0xd1002041 ${ivt_ptr_base} 0x00000000 0x00000000 0x00000000 +${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin +dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc
+To generate CSF signature for the fitImage part of flash.bin container,
use CST:
+``` +cst -i csf_fit.tmp -o csf_fit.bin +```
+Finally, patch the CSF signature into the fitImage right past the IVT: +``` +dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} +conv=notrunc ```
+The entire script is available in +doc/imx/habv4/csf_examples/mx8m/csf.sh
+1.4 Closing the device +-----------------------
+The procedure for closing the device is similar as in Non-SPL targets, +for a complete procedure please refer to section "1.5 Programming SRK +Hash" in mx6_mx7_secure_boot.txt document available under +doc/imx/habv4/guides/ directory.
+References: +[1] AN4581: "Secure Boot on i.MX 50, i.MX 53, i.MX 6 and i.MX 7 Series
+using HABv4" - Rev 2.
2.35.1
Please stop top-posting.
Regarding the documentation available in codeaurora git, that does not work with upstream U-Boot using binman. However, it does at least explain why people get confused to think this second image is the way image authentication should be done on mx8m, and then fail to get anything working, so thanks for that clarification.
Add HABv4 documentation extension for SPL targets covering the following topics:
- How to sign an securely boot an flash.bin container image.
- How to extend the root of trust for additional boot images.
- Add SPL and fitImage CSF examples.
- Add signature generation script example.
Signed-off-by: Marek Vasut marex@denx.de Cc: Breno Lima breno.lima@nxp.com Cc: Fabio Estevam festevam@denx.de Cc: Heiko Schocher hs@denx.de Cc: Peng Fan peng.fan@nxp.com Cc: Stefano Babic sbabic@denx.de Cc: Utkarsh Gupta utkarsh.gupta@nxp.com Cc: Ye Li ye.li@nxp.com
Applied to u-boot-imx, master, thanks !
Best regards, Stefano Babic
participants (3)
-
Marek Vasut -
sbabic＠denx.de -
Utkarsh Gupta