putting together a student lab for building u-boot for the BBB
(which i'll post shortly for anyone who's interested), and just
noticed that when i boot from a minimally-populated SD card (that is,
nothing but MLO and u-boot.ing and an empty uEnv.txt), u-boot still
insists on checking out possible partitions in eMMC, which i *don't*
want it to do.
here's snippets of the output on the console. first, i can see where
it consults the uEnv.txt file in the VFAT partition, which is
deliberately empty:
... snip ...
mmc0 is current device
gpio: pin 54 (gpio 54) value is 1
Checking for: /uEnv.txt ...
reading uEnv.txt <-- good
0 bytes read in 3 ms (0 Bytes/s)
... snip ...
but further down, u-boot runs off to eMMC and pulls in uEnv.txt files
there as well:
... snip ...
switch to partitions #0, OK
mmc1(part 0) is current device
gpio: pin 54 (gpio 54) value is 1
Checking for: /uEnv.txt ...
reading uEnv.txt
26 bytes read in 3 ms (7.8 KiB/s) <-- there ...
gpio: pin 55 (gpio 55) value is 1
Loaded environment from uEnv.txt
Importing environment from mmc ...
Checking if uenvcmd is set ...
Checking if client_ip is set ...
Checking for: /boot.scr ...
Checking for: /boot/boot.scr ...
Checking for: /boot/uEnv.txt ...
gpio: pin 55 (gpio 55) value is 1
33 bytes read in 42 ms (0 Bytes/s) <-- ... and there
Loaded environment from /boot/uEnv.txt
... snip ...
for the purposes of simplicity, i would prefer that u-boot consult
nothing beyond the SD card ... without reconfiguring and rebuilding
u-boot, what is the easiest way to do that? thanks.
rday
--
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Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
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