Hi Tom,
[Adding Bryan]
On Thu, Feb 4, 2021 at 12:49 AM Tom Rini <tr...@konsulko.com> wrote:
> CONFIG_SERIAL_TAG is only used to configure the ATAG serial record. It
> does nothing else. On i.MX8* this is already being discarded. On i.MX7
> we see things like:
> warp7 : all -144 rodata +32 text -176
> u-boot: add: 0/-2, grow: 0/-2 bytes: 0/-160 (-160)
> function old new
> delta
> params 4 -
> -4
> get_board_serial 20 -
> -20
> board_late_init 96 56
> -40
> boot_prep_linux 156 60
> -96
But then it will remove the support of reading serial number via fuses
which was added by:
commit 852cc548b3fdf6d5b46e2a96f876d14608ccdcf4
Author: Bryan O'Donoghue <bryan.odonog...@linaro.org>
Date: Mon Mar 26 15:27:34 2018 +0100
warp7: Set u-boot serial# based on OTP value
u-boot has a standard "serial#" environment variable that is suitable
for storing the iSerial number we will supply via the USB device
descriptor. serial# is automatically picked up by the disk subsystem in
u-boot - thus providing a handy unique identifier in /dev/disk/by-id as
detailed below.
Storing the hardware serial identifier in serial# means we can change the
serial# if we want before USB enumeration - thus making iSerial automatic
via OTP but overridable if necessary.
This patch reads the defined OTP fuse and sets environment variable
"serial#" to the value read.
With this patch in place the USB mass storage device will appear in
/dev/disk/by-id with a unique name based on the OTP value. For example
/dev/disk/by-id/usb-Linux_UMS_disk_0_WaRP7-0xf42400d3000001d4-0:0
Signed-off-by: Bryan O'Donoghue <bryan.odonog...@linaro.org>
Cc: Fabio Estevam <fabio.este...@nxp.com>
Cc: Rui Miguel Silva <rui.si...@linaro.org>
Cc: Ryan Harkin <ryan.har...@linaro.org>
Reviewed-by: Fabio Estevam <fabio.este...@nxp.com>
> Currently, yes. Historically ever? Or even if so, you're OK just removing
> all
> of that code as well? Thanks.
mx5 and mx6 used to boot board files in the past (NXP kernel 2.6.35
for mx5 or 3.0.x for mx6).
Such kernels are not even maintained by the NXP, so we should not
worry about booting non-DT with i.MX.
