I studied secure boot doc (e.g. AN4581.pdf, AN12056.pdf) and tried to download signed boot image to device via mfgtool according to Step 4 ~ Step 6 of attached test procedures, but it was hang (for LED is not on) and console does not show any message after HW switch from serial download mode to internal mode.
Detailed info are listed in below. Could anyone provide advice which steps are wrong or how to debug it?
Thanks a lot.
No matter SRK fuses are blown or not, DCD address is set to 0x910000 or 0x911000, it has the same symptom.
The device is not closed for I just blow SRK (and it can work if I download unsigned boot image).
1. [Device info] CPU: i.MX7D rev1.3, Boot code version: U-Boot 2017.03-nxp/imx_v2017.03_4.9.11_1.0.0
2. Refer to http://www.voidcn.com/article/p-rwpukyng-bdq.html and revised it for i.MX7D as attached.
(1) Most of them are the same except u-boot image does not need to pad by ourselves.
(2) According to “Appendix F. i.MX manufacturing tool”, user must set the image start address >= 0x911000 for i.MX7D Rev D.
(3) I don't set BOOT mode via command as step 6.4. (I set it via HW jump switch).
3. Download image via mfgtool
(1) Replace signed boot image into mfgtools\Profiles\Linux\OS Firmware\files
(2) Switch HW jump to serial download mode and download image to device.
It would blow fuse for SRK and dump SRK via cat cat /sys/fsl_otp/HW_OCOTP_SRK0 ~ 7. (The SRK values are the same as we set)
(3) Switch HW jump to internal mode
=> But LED is not on (device is hang?) and console does not show any message (e.g. boot version, CPU info, etc) after power on.