This page gives an overview of the zynqmp_nvmem driver which is available as part of the ZynqMP Linux distribution. Paths, files, links and documentation on this page are given relative to the Linux kernel source tree.
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HW IP Features
- SoC revision information
- Efuse memory access.
Features supported in driver
- SoC revision information
- Programming and reading efuse memory
Missing Features, Known Issues and Limitations
- None.
Kernel Configuration
Device Drivers ---> NVMEM Support ---> <*> Xilinx ZYNQMP SoC ID suppor
Devicetree
| Code Block | ||
|---|---|---|
| ||
nvmem_firmware {
compatible = "xlnx,zynqmp-nvmem-fw";
#address-cells = <1>;
#size-cells = <1>;
soc_revision: soc_revision@0 {
reg = <0x0 0x4>;
};
/* efuse access */
efuse_dna: efuse_dna@c {
reg = <0xc 0xc>;
};
efuse_usr0: efuse_usr0@20 {
reg = <0x20 0x4>;
};
efuse_usr1: efuse_usr1@24 {
reg = <0x24 0x4>;
};
efuse_usr2: efuse_usr2@28 {
reg = <0x28 0x4>;
};
efuse_usr3: efuse_usr3@2c {
reg = <0x2c 0x4>;
};
efuse_usr4: efuse_usr4@30 {
reg = <0x30 0x4>;
};
efuse_usr5: efuse_usr5@34 {
reg = <0x34 0x4>;
};
efuse_usr6: efuse_usr6@38 {
reg = <0x38 0x4>;
};
efuse_usr7: efuse_usr7@3c {
reg = <0x3c 0x4>;
};
efuse_miscusr: efuse_miscusr@40 {
reg = <0x40 0x4>;
};
efuse_chash: efuse_chash@50 {
reg = <0x50 0x4>;
};
efuse_pufmisc: efuse_pufmisc@54 {
reg = <0x54 0x4>;
};
efuse_sec: efuse_sec@58 {
reg = <0x58 0x4>;
};
efuse_spkid: efuse_spkid@5c {
reg = <0x5c 0x4>;
};
efuse_ppk0hash: efuse_ppk0hash@a0 {
reg = <0xa0 0x30>;
};
efuse_ppk1hash: efuse_ppk1hash@d0 {
reg = <0xd0 0x30>;
};
}; |
...
| Register | Read | Write | Size in bytes | Offset is |
|---|---|---|---|---|
| Version | YES | NO | 0x0 | 0x4 |
| DNA | YES | NO | 0xc | 0xC |
| User0 | YES | YES | 0x4 | 0x20 |
| User1 | YES | YES | 0x4 | 0x24 |
| User2 | YES | YES | 0x4 | 0x28 |
| User3 | YES | YES | 0x4 | 0x2c |
| User4 | YES | YES | 0x4 | 0x30 |
| User5 | YES | YES | 0x4 | 0x34 |
| User6 | YES | YES | 0x4 | 0x38 |
| User7 | YES | YES | 0x4 | 0x3C |
| Misc user | YES | YES | 0x4 | 0x40 |
| Secure control | YES | YES | 0x4 | 0x58 |
| SPK ID | YES | YES | 0x4 | 0x5C |
| AES key | NO | YES | 0x20 | 0x60 |
| PPK0 hash | YES | YES | 0x30 | 0xA0 |
| PPK1 hash | YES | YES | 0x30 | 0xD0 |
Reading/writing unrestricted number of bytes results into an error.
Restricted bits from programming:
Secure Control eFuses :
- RSA_EN (BITS - [25:11])
- DFT_DIS (BIT-6 )
- JTAG_DIS (BIT-5)
- ENC_ONLY (BIT - 2)
Misc User Control eFuses :
- LBIST_EN (BIT - 10)
Expected Output
| Code Block | ||
|---|---|---|
| ||
For Version reading: offset is 0x0 and bytes are 4 ########## For Silicon 1.0 ############ root@plnx_aarch64:~# dd if=/sys/bus/nvmem/devices/zynqmp-nvmem0/nvmem of=/tmp/version.bin bs=4 count=1 root@plnx_aarch64:~# hexdump -v /tmp/version.bin 0000000 0000 0000001 ########## For Silicon 2.0 ############ root@plnx_aarch64:~# dd if=/sys/bus/nvmem/devices/zynqmp-nvmem0/nvmem of=/tmp/version.bin bs=4 count=1 root@plnx_aarch64:~# hexdump -v /tmp/version.bin 0000000 0001 0000001 ########## For Silicon 3.0 ############ root@plnx_aarch64:~# dd if=/sys/bus/nvmem/devices/zynqmp-nvmem0/nvmem of=/tmp/version.bin bs=4 count=1 root@plnx_aarch64:~# hexdump -v /tmp/version.bin 0000000 0002 0000001 ########## For Silicon 4.0 ############ root@plnx_aarch64:~# dd if=/sys/bus/nvmem/devices/zynqmp-nvmem0/nvmem of=/tmp/version.bin bs=4 count=1 root@plnx_aarch64:~# hexdump -v /tmp/version.bin 0000000 0003 0000001 EFUSE access To read user fuse 7 root@xilinx-zcu102-2018_3:/mnt# dd if=/sys/bus/nvmem/devices/zynqmp-nvmem0/nvmem of=/tmp/userfuse.bin bs=4 count=1 skip=15 1+0 records in 1+0 records out root@xilinx-zcu102-2018_3:/mnt# hexdump -v /tmp/userfuse.bin 0000000 0000 af00 0000004 |
| Register | Size in bytes(hex) | Offset (hex) | bs(dec) | count(dec) | skip(dec) |
|---|---|---|---|---|---|
| Version | 0 | 4 | 4 | 0 | 1 |
| User7 | 4 | 3C | 4 | 1 | 15 |
| User6 | 4 | 38 | 4 | 1 | 14 |
| User5 | 4 | 34 | 4 | 1 | 13 |
| User4 | 4 | 30 | 4 | 1 | 12 |
| User3 | 4 | 2C | 4 | 1 | 11 |
| User2 | 4 | 28 | 4 | 1 | 10 |
| User1 | 4 | 24 | 4 | 1 | 9 |
| User0 | 4 | 20 | 4 | 1 | 8 |
| SPK ID | 4 | 5C | 4 | 1 | 23 |
| Secure Control | 4 | 58 | 4 | 1 | 22 |
| PPK1 hash | 30 | D0 | 4 | 12 | 52 |
| PPK0 hash | 30 | A0 | 4 | 12 | 40 |
| Misc user | 4 | 40 | 4 | 1 | 16 |
| DNA | C | C | 12 | 1 | 1 |
Known Limitation : dd command can be used to read one word of data only (This means bs =4 and count =1). Therefore dd command cannot be used for reading PPK0/1. Linux application provided in wiki page can be used to read PPK0/1 values .
Using linux application
As an alternative to dd command, a linux application can be used to read/write into eFuse from linux.
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