Boot Configurations#

The following table shows the programmable boot configuration fields. The boot configurations can be done in either the eFuse (OTP) or NWP MBR.

S.no Field Description Number of bits Default Setting in MBR Default setting in eFuse/OTP Is a security feature?
1 enable_autobaud_detection

1: Auto baud rate detection for UART is enabled

0: Auto baud disabled

Default baud rate – 115200 bps

1 Disabled: 0 0 No
2 safe_upgrade_frm_host

1: Upgrade the image from backup, instead of overwriting the primary location directly.

0: Overwrite the primary location directly.

1 Enabled: 1 0 Yes
3 disable_ta_jtag

0: Enable NWP JTAG interface.

1: Disable NWP JTAG interface.

Refer to Debug Lock section.

1 Enabled: 0 0 Yes
4 enable_glitch_mitigation

If glitch mitigation is enabled, the efuse bits related to the JTAG interface are read again before enabling or disabling the JTAG interface.

1: Enable reading efuse bits related to JTAG interface again before enabling or disabling JTAG interface.

0: Disable reading efuse bits related to JTAG interface again before enabling or disabling JTAG interface.

1 Disabled: 0 0 Yes
5 ta_anti_roll_back

This feature prevents the NWP firmware from being downgraded to older versions.

1: Enable the Anti Rollback feature.

0: Disable the Anti Rollback feature.

1 Disabled: 0 0 Yes
6 ta_secure_boot_enable

1: Enable Secure Boot for NWP.

0: Disable Secure Boot for NWP.

1 Disabled: 0 0 Yes
7 ta_digital_signature_validation

1: Digital signature validation is enabled for NWP firmware.

0: Digital signature validation is disabled for NWP firmware.

1 Disabled: 0 0 Yes
8 ta_encrypt_firmware

00: Firmware is stored in an unencrypted form in the flash.

01: Firmware is stored in an encrypted form in the flash using CTR mode.

10: Firmware is stored in an encrypted form in the flash using XTS mode.

11: Reserved for future use.

2 Disabled: 00 0 Yes
9 mbr_mic_sign_enable

Enable MIC and Signature for the combined memory region, which includes the MBR, Boot Descriptor, and Key Descriptor Table.

00: CRC

01: MIC

10: Reserved

11: Sign

Applicable only when key is present in OTP.

2 CRC check is enabled: 00 0 Yes
10 mic_protected_content_length

This field depicts how much space is MIC protected using OTP key and MIC stored in OTP.

See MIC Protected Content Length Map.

4 Disabled: 0 0 Yes
11 ta_otp_lock_r1

This is a programming lock for the NWP OTP, specifically for the R1 address region (0–127). When the OTP is locked, the user cannot modify the secure boot-related parameters present in the R1 address region.

1: NWP OTP programming is locked.

0: NWP OTP programming is not locked.

1 NA 0 Yes