Hello, community
I have some questions about DCD verification.
In IMX6SDLRM 8.5.4.3 ECSPI Boot, there is description as bellow.
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The boot ROM code copies 4 KB data from EEPROM device to the internal RAM. If
DCD verification is successful, the ROM code copies the initial 4 KB data, as well as the
rest of the image extracted from application image, directly to the application destination.
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Q1)
Could you tell me the detail of DCD verification(How is the verification done)?
Q2)
If the DCD verification is failed,what is the next action?
Thank you!
ZongbiaoLiao
For Q1, you can think the DCD is a data struct, and it has some special tags. The boot ROM will verify if it is a valid DCD struct for boot up.
For Q2, that means boot failure happens, it will swicth to serial download mode.
Hello,
Section 8.6.2 [Device Configuration Data (DCD)] of the RM describes
possible restrictions for DCD commands in NOTE comments.
In particular, Table 8-33 (Valid DCD Address Ranges) provides allowed
addresses to access.
If the DCD verification is failed :
1) Redundant Boot is activated (if enabled) ;
2) SD/MMC Manufacture Mode is entered (section 8.11 SD/MMC Manufacture Mode) ;
3) Serial (USB) bootloader is entered.
Have a great day,
Yuri
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