does fw_printenv/fw_setenv work for UBOOT on Tegra Jetson?
The tools fw_printenv/fw_setenv in the uboot source tree normally work with mtd partitions and I have seen hints on the web for emmc support for these tools. Normally you configure these tools with the file tools/env/fw_env.config to tell it what device and address offset to use to read/write the uboot environment variables from linux.
It appears that the EMMC flash address used to store the uboot environment variables is not a visible partition after the kernel boots ( After booting linux I have dumped the entire /dev/mmcblk0 partition to a file and a search of this does not show the expected uboot environment data )
After looking through the uboot source code I determined the uboot partition/offset where the environment variables were stored and I can dump the raw environment byte stream with:
mmc dev 0 2
mmc read 80800000 1ff0 1
I do not understand the relationship with the uboot partitions and the /dev/mmcblk0pX partitions that are visible after the kernel boots. The flash is 16 GiB, but a dump of /dev/mmcblk0 shows a size of about 14.7 GiB, I am assuming this is because the entire flash is not visiable after the kernel boots.
Anyway, all i need is for uboot’s fw_printenv/fw_setenv linux tools to work, is this possible on the tegra?