From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Thu, 4 Feb 2021 08:26:52 -0500 Subject: [PATCH 02/13] arm: imx: Remove unused CONFIG_xxx_TAG support In-Reply-To: References: <20210204022415.20589-1-trini@konsulko.com> <20210204022415.20589-2-trini@konsulko.com> <20210204034934.GV10169@bill-the-cat> Message-ID: <20210204132652.GY10169@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Feb 04, 2021 at 06:56:47AM -0300, Fabio Estevam wrote: > Hi Tom, > > [Adding Bryan] > > On Thu, Feb 4, 2021 at 12:49 AM Tom Rini 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 > 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 > Cc: Fabio Estevam > Cc: Rui Miguel Silva > Cc: Ryan Harkin > Reviewed-by: Fabio Estevam I did miss that one. I'm not sure if that's abusing a symbol or clever use of the symbol. I will have to v2 this one then. > > 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. So you're OK with removing ATAGs support from i.MX5/6 from mainline? But there's the unresolved question of the best way to populate "serial#". Yes? Thanks. -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 659 bytes Desc: not available URL: