BELK-TN-010: MAC address programming on OTP
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This technical note was validated against specific versions of hardware and software. What is described here may not work with other versions. |
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History[edit | edit source]
| Version | Date | BELK/BXELK version | Notes |
|---|---|---|---|
| 1.0.1 | Jul 2021 | 4.1.4 | BELK update 4.1.4 |
Introduction[edit | edit source]
Every network adapter has a Media Access Control address (usually shortened to MAC address). A MAC address is a six-byte identifying number permanently embedded in the firmware of the adapter, and is readable by the network and the operating system of the device on which the adapter is installed.
The address must follow the standards set by the Institute of Electrical and Electronics Engineers (IEEE), which sets computer networking standards.
The MAC address is a six-pair set of hexadecimal numbers, for example a1-c2-e3-44-5f-6d. The purpose of the MAC address is to uniquely identify every node; every adapter has a unique MAC address.
Permanent storage areas[edit | edit source]
Some SOCs provide programmable OTPs for security, MAC address, boot modes, etc. Usually, some of these are general-purpose registers and can be managed by the user.
In other cases, an external permanent storage device can be used for storing permanent settings like the MAC address: for the Bora/BoraX product family, DAVE proposes to use the OTP block on NOR SPI flash for storing permanently ConfigID, UniqueID and MAC address.
About this document[edit | edit source]
In this Application Note, we will describe how to use the Bora/BoraX NOR SPI for programming and using the MAC address programmed on its OTP block area.
MAC address programming how-to[edit | edit source]
Accessing NOR SPI and u-boot update[edit | edit source]
Actual u-boot version belk-4.1.1 has native macros for managing the u-boot update. Here below the messages using the boot from NOR QSPI:
U-Boot SPL 2017.01-belk-4.1.1 (Jan 08 2020 - 16:44:36) qspi boot Trying to boot from SPI U-Boot 2017.01-belk-4.1.1 (Jan 08 2020 - 16:44:36 +0100), Build: belk-4.1.1 Model: Bora Board: Xilinx Zynq I2C: ready DRAM: ECC disabled 1 GiB Relocating to 3ff14000, new gd at 3ead3ee8, sp at 3ead3ec0 NAND: 1024 MiB MMC: Card did not respond to voltage select! Card did not respond to voltage select! sdhci@e0100000 - probe failed: -95 Card did not respond to voltage select! SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB *** Warning - bad CRC, using default environment In: serial@e0001000 Out: serial@e0001000 Err: serial@e0001000 Model: Bora Board: Xilinx Zynq SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB WARNING: ConfigID on block 0 is UNLOCKED SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB SOM ConfigID#: 00000006 SOM UniqueID#: 3a12db08:32291263 ds2431_readmem(): error in chip reset ds2431_readmem(): error in reading buffer ds2431_readmem(): error in chip reset ds2431_readmem(): error in reading buffer CB ConfigID CRC mismatch for 0x00000000 (was 0x00000000, expected 0x2144df1c) at block 3 (offset 96): using default CB ConfigID#: ffffffff CB UniqueID#: 00000000:00000000 Net: ZYNQ GEM: e000b000, phyaddr 7, interface rgmii-id eth0: ethernet@e000b000 Hit ENTER within 3 seconds to stop autoboot Bora>
The following macros can be used for u-boot re-programming:
load_spl=tftpboot ${loadaddr} bora/boot.bin
update_spl=sf probe 0 0 0;sf erase ${SPL_base} +${filesize};sf write ${loadaddr} ${SPL_base} ${filesize}
load=tftpboot ${loadaddr} bora/u-boot.img
update=sf probe 0 0 0;sf erase ${u-boot_base} +${filesize};sf write ${loadaddr} ${u-boot_base} ${filesize}
with proper settings (i.e. binary filenames)
ethaddr[edit | edit source]
Into the u-boot source code, a default value for the ethernet MAC address is set to the DAVE's default MAC value, i.e.:
Bora> pri ethaddr ethaddr=00:50:C2:1E:AF:E0 Bora>
random MAC address[edit | edit source]
If the ethaddr variable is deleted from the environment, a random value is generated by u-boot:
Bora> setenv ethaddr Bora> saveenv Saving Environment to SPI Flash... SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Erasing SPI flash...Writing to SPI flash...done Valid environment: 2 Bora> reset resetting ...
Warning: ethernet@e000b000 (eth0) using random MAC address - ae:a4:d7:3c:57:ff eth0: ethernet@e000b000 Hit ENTER within 3 seconds to stop autoboot Bora>
Accessing the NOR SPI OTP area[edit | edit source]
For accessing the NOR OTP blocks area a special u-boot version should be used.
The proper defconfig should be used for compiling a development binary which allows to use the writing commands on this area:
For Bora SOM:
make bora_mmc_devel_defconfig
For BoraX SOM:
make borax_mmc_devel_defconfig
u-boot devel[edit | edit source]
The u-boot devel version can be used for the application purposes: in this application note we used the new u-boot release with the following files:
belk-4.1.4_borax_mmc_devel_boot.bin belk-4.1.4_borax_mmc_devel_u-boot.img
The devel u-boot version provides a new command (hidden into standard relase) used for the MAC management:
Bora> macprog macprog - MAC address in SPI NOR OTP management Usage: macprog <cmd> ethaddr - program ethaddr environment variable in OTP eth1addr - program eth1addr environment variable in OTP lock_ethaddr - lock OTP block where ethaddr is stored lock_eth1addr - lock OTP block where eth1addr is stored Bora>
Simply properly copied into a FAT32 SD card with the default filename (for the bootrom readability) boot.bin and u-boot.img.
Bora> fatls mmc 0:1
system volume information/
88892 boot.bin
688280 u-boot.img
2 file(s), 1 dir(s)
Bora>
Once programmed, the devel u-boot version provides the command required:
U-Boot SPL 2017.01-belk-4.1.4 (Jul 30 2021 - 10:13:19) mmc boot Trying to boot from MMC1 reading fpga.bit reading fpga.bit design filename = "bora_wrapper;UserID=0XFFFFFFFF;Version=2017.1" part number = "7z020clg400" date = "2020/01/08" time = "15:46:46" bytes in bitstream = 4045564 zynq_align_dma_buffer: Align buffer at 400006c to 3ffff80(swap 1) reading u-boot.img reading u-boot.img U-Boot 2017.01-belk-4.1.4 (Jul 30 2021 - 10:13:19 +0200) Model: Bora Board: Xilinx Zynq I2C: ready DRAM: ECC disabled 1 GiB Relocating to 3ff13000, new gd at 3ead2ee8, sp at 3ead2ec0 NAND: 1024 MiB MMC: sdhci@e0100000: 0 (SD) reading bora.env In: serial@e0001000 Out: serial@e0001000 Err: serial@e0001000 Model: Bora Board: Xilinx Zynq SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB SOM ConfigID#: 00000001 SOM UniqueID#: 01234567:89abcdef ds2431_readmem(): error in chip reset ds2431_readmem(): error in reading buffer ds2431_readmem(): error in chip reset ds2431_readmem(): error in reading buffer CB ConfigID CRC mismatch for 0x00000000 (was 0x00000000, expected 0x2144df1c) at block 3 (offset 96): using default CB ConfigID#: ffffffff CB UniqueID#: 00000000:00000000 SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB ethaddr in SPI NOR: CRC mismatch for 0x0000000000000000 (was 0x00000000, expected 0x6522df69) at block 8 Net: ZYNQ GEM: e000b000, phyaddr 7, interface rgmii-id Warning: ethernet@e000b000 (eth0) using random MAC address - ae:6d:59:6e:aa:87 eth0: ethernet@e000b000 Hit ENTER within 3 seconds to stop autoboot Bora> macprog macprog - MAC address in SPI NOR OTP management Usage: macprog <cmd> ethaddr - program ethaddr environment variable in OTP eth1addr - program eth1addr environment variable in OTP lock_ethaddr - lock OTP block where ethaddr is stored lock_eth1addr - lock OTP block where eth1addr is stored Bora>
The MAC not programmed is shown by the two debug messages:
ethaddr in SPI NOR: CRC mismatch for 0x0000000000000000 (was 0x00000000, expected 0x6522df69) at block 8 Warning: ethernet@e000b000 (eth0) using random MAC address - ae:6d:59:6e:aa:87
Programming the required MAC address[edit | edit source]
For programming the MAC address the following steps can be used:
- set the
ethaddrethernet address value
Bora> setenv ethaddr 00:50:C2:1E:AF:EC Bora> printenv ethaddr ethaddr=00:50:C2:1E:AF:EC Bora>
- programming the MAC and lock the OTP register
Bora> macprog ethaddr SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Your're about to program this MAC address: 00:50:C2:1E:AF:EC for ethaddr (block 8). Continue? (y/N) y Block 8 NOT locked. Use 'macprog lock_ethaddr' to lock it Bora> macprog lock_ethaddr You're about to lock block 8. Continue (y/N)? y SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Bora>
incorrect ethaddr[edit | edit source]
If ethaddr is empty the macprog command will report an error:
Bora> setenv ethaddr Bora> macprog ethaddr Error: "ethaddr" not defined Bora>
u-boot[edit | edit source]
Once the MAC address has been programmed, the standard u-boot version can be used in the field.
Typically, the NOR SPI is used as boot storage device, so the defconfig used for the binary version is:
- for Bora SOM: bora_qspi_defconfig (i.e. u-boot has to compiled with
make bora_qspi_defconfig) - for BoraX SOM: borax_qspi_defconfig (i.e. u-boot has to compiled with
make borax_qspi_defconfig)
Verify the programmed MAC address[edit | edit source]
The MAC address can be checked using the on the field u-boot version:
- install the u-boot field version using the u-boot binaries
belk-4.1.4_bora_qspi_boot.bin belk-4.1.4_bora_qspi_u-boot.img
and reset the board.
- the configured MAC address is available in the variable
ethaddr
U-Boot SPL 2017.01-belk-4.1.4 (Jul 30 2021 - 10:24:26) qspi boot Trying to boot from SPI U-Boot 2017.01-belk-4.1.4 (Jul 30 2021 - 10:24:26 +0200) Model: Bora Board: Xilinx Zynq I2C: ready DRAM: ECC disabled 1 GiB Relocating to 3ff14000, new gd at 3ead3ee8, sp at 3ead3ec0 NAND: 1024 MiB MMC: Card did not respond to voltage select! Card did not respond to voltage select! sdhci@e0100000 - probe failed: -95 Card did not respond to voltage select! SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB In: serial@e0001000 Out: serial@e0001000 Err: serial@e0001000 Model: Bora Board: Xilinx Zynq SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB SOM ConfigID#: 00000001 SOM UniqueID#: 01234567:89abcdef ds2431_readmem(): error in chip reset ds2431_readmem(): error in reading buffer ds2431_readmem(): error in chip reset ds2431_readmem(): error in reading buffer CB ConfigID CRC mismatch for 0x00000000 (was 0x00000000, expected 0x2144df1c) at block 3 (offset 96): using default CB ConfigID#: ffffffff CB UniqueID#: 00000000:00000000 SF: Detected s25fl256s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Net: ZYNQ GEM: e000b000, phyaddr 7, interface rgmii-id eth0: ethernet@e000b000 Hit ENTER within 0 seconds to stop autoboot Bora>
It is possible to change (using an environment override) the MAC address simply assigning a new value; in this case, the reboot displays the incongruent value and uses the last one:
Bora> pri ethaddr ethaddr=00:50:c2:1e:af:ec Bora> setenv ethaddr 00:50:c2:1e:af:aa Bora> saveenv Saving Environment to SPI Flash... SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Erasing SPI flash...Writing to SPI flash...done Valid environment: 2 Bora> reset resetting ... ... ... Warning: ethaddr MAC addresses don't match: Address in SROM is 00:50:c2:1e:af:ec Address in environment is 00:50:c2:1e:af:aa Net: ZYNQ GEM: e000b000, phyaddr 7, interface rgmii-id eth0: ethernet@e000b000 Hit ENTER within 3 seconds to stop autoboot
For using the OTP MAC, simply delete the ethaddr and save the environment:
Bora> pri ethaddr ethaddr=00:50:c2:1e:af:aa Bora> setenv ethaddr Bora> saveenv Saving Environment to SPI Flash... SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Erasing SPI flash...Writing to SPI flash...done Valid environment: 1 Bora> reset resetting ... ... ... SF: Detected s25fl128s_64k with page size 256 Bytes, erase size 64 KiB, total 32 MiB Net: ZYNQ GEM: e000b000, phyaddr 7, interface rgmii-id eth0: ethernet@e000b000 Hit ENTER within 3 seconds to stop autoboot Bora> pri ethaddr ethaddr=00:50:c2:1e:af:ec Bora>
Linux userspace access[edit | edit source]
The programmed MAC value can be verified once the ethernet interface has been correctly configured by u-boot and then activated by the Linux kernel.
It is enough to check it using ifconfig at the userspace level:
root@bora:~# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:50:c2:1e:af:ec
inet addr:192.168.0.90 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11620 errors:0 dropped:4 overruns:0 frame:0
TX packets:9125 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:12494336 (11.9 MiB) TX bytes:1189523 (1.1 MiB)
Interrupt:148 Base address:0xb000
root@bora:~#
Bora git repositories[edit | edit source]
DAVE's Bora/BoraX git repositories have been updated with the latest development release which includes the routines for accessing the NOR OTP area and storing the MAC address.
The git repositories can be accessed, for DAVE's enabled Customers, at the following addresses:
git@git.dave.eu:dave/bora/u-boot-xlnx.git
The Bora Building_U-Boot wiki page describes how to keep updated with DAVE's git repository and build the required u-boot version.
The binaries used in this AN can be found into our mirror server
