[Buildroot] [EXT] Re: [PATCH v2 06/10] boot/arm-trusted-firmware: Add RCW support

[Jerry Huang <jerry.huang@nxp.com>]

I double check the "boot/arm-trusted-firmware/Config.in",
There is one option BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES,
I think it can be used to replace my previous mail mentioned: ARM_TRUSTED_FIRMWARE_EXTRA_OPTS.
Add now this option is added to ARM_TRUSTED_FIRMWARE_MAKE_OPTS

So in order to keep consistent with the context, two new options are defined:
BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_TARGETS
BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_ DEPENDENCIES

ARM_TRUSTED_FIRMWARE_MAKE_TARGETS += BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_TARGETS
ARM_TRUSTED_FIRMWARE_DEPENDENCIES += BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_ DEPENDENCIES

Best Regards
Jerry Huang

> -----Original Message-----
> From: Jerry Huang
> Sent: Tuesday, November 26, 2019 3:07 PM
> To: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> Cc: buildroot at busybox.net; michael at walle.cc; matthew.weber at collins.com;
> geomatsi at gmail.com
> Subject: RE: [EXT] Re: [Buildroot] [PATCH v2 06/10] boot/arm-trusted-firmware:
> Add RCW support
> 
> Hi, Thomas,
> Some comment in lines, please review them, thanks a lot.
> 
> Best Regards
> Jerry Huang
> 
> > -----Original Message-----
> > From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> > Sent: Tuesday, November 26, 2019 6:10 AM
> > To: Jerry Huang <jerry.huang@nxp.com>
> > Cc: buildroot at busybox.net; michael at walle.cc;
> > matthew.weber at collins.com; geomatsi at gmail.com
> > Subject: [EXT] Re: [Buildroot] [PATCH v2 06/10]
> > boot/arm-trusted-firmware: Add RCW support
> >
> > Caution: EXT Email
> >
> > Hello,
> >
> > On Thu, 21 Nov 2019 18:23:20 +0800
> > Changming Huang <jerry.huang@nxp.com> wrote:
> >
> > > diff --git a/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> > > b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> > > index 2133d39e6d..2bca8109f1 100644
> > > --- a/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> > > +++ b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> > > @@ -92,6 +92,15 @@ endif
> > >
> > >  ARM_TRUSTED_FIRMWARE_MAKE_TARGETS = all
> > >
> > > +ifeq ($(BR2_PACKAGE_HOST_RCW_ATF),y)
> >
> > This option should be introduced by this patch.
> Sure,
> 
> > Overall, I'm not super happy with how arm-trusted-firmware works. In
> > some cases, it's a sub-option of arm-trusted-firmware that causes it
> > to use some additional package (for example OPTEE as BL32, U-Boot as
> > BL33), but sometimes it's the implicit fact of having another package
> > enabled (mv-ddr-marvell, vexpress-firmware), that causes
> arm-trusted-firmware to use it.
> > Not great.
> >
> > So I'm not sure how to proceed with RCW.
> Yes, it uses some additional package for booting.
> But, if it does not use them (U-Boot as BL33, OPTEE as BL32, RCW as BL2), what
> can arm-trusted-firmware do?
> 
> > > +RCW_BOOT_MODE = $(call
> > qstrip,$(BR2_PACKAGE_HOST_RCW_BOOT_MODE))
> > > +RCW_PATH = $(call qstrip,$(BR2_PACKAGE_HOST_RCW_BIN))
> > > +RCW_FILE = $(lastword $(subst /, ,$(RCW_PATH)))
> >
> > Those variables names should be prefixed with the package name, i.e
> > ARM_TRUSTED_FIRMWARE.
> Sure,
> 
> > > +ARM_TRUSTED_FIRMWARE_MAKE_OPTS +=
> > BOOT_MODE=$(RCW_BOOT_MODE)
> > > +RCW=$(BINARIES_DIR)/$(RCW_FILE)
> >
> > These BOOT_MODE and RCW options are not supported in ATF upstream,
> > apparently only in the NXP fork. I'm not sure we want explicit support
> > for vendor-specific things. Should we look at providing an
> > arm-trusted-firmware that can more easily be customized through options?
> 
> Maybe we can provide three options
> ARM_TRUSTED_FIRMWARE_EXTRA_OPTS: the custom OPTS
> ARM_TRUSTED_FIRMWARE_EXTRA_TARGETS: the custom TARGETS
> ARM_TRUSTED_FIRMWARE_EXTRA_DEPENDENCIES: the custom dependency
> 
> Which are defined in defconfig file or empty, For example, NXP QorIQ:
> ARM_TRUSTED_FIRMWARE_EXTRA_OPTS = " BOOT_MODE=sd
> RCW=$(BINARIES_DIR)/ rcw_1300_sdboot.bin"
> ARM_TRUSTED_FIRMWARE_EXTRA_TARGETS = " pbl"
> ARM_TRUSTED_FIRMWARE_EXTRA_DEPENDENCIES = "host-qoriq-rcw"
> Or Marvell DDR:
> ARM_TRUSTED_FIRMWARE_EXTRA_OPTS = "
> SCP_BL2=$(BINARIES_DIR)/scp-fw.bin"
> ARM_TRUSTED_FIRMWARE_EXTRA_DEPENDENCIES = "mv-ddr-marvell"
> 
> we can use them as below without detecting the condition in ATF makefile:
> ARM_TRUSTED_FIRMWARE_MAKE_OPTS +=
> ARM_TRUSTED_FIRMWARE_EXTRA_OPTS
> ARM_TRUSTED_FIRMWARE_MAKE_TARGETS +=
> ARM_TRUSTED_FIRMWARE_EXTRA_TARGETS
> ARM_TRUSTED_FIRMWARE_DEPENDENCIES +=
> ARM_TRUSTED_FIRMWARE_EXTRA_DEPENDENCIES
> 
> We can put anything we want into these options, and the ATF makefile is very
> clean.
> 
> How do you think about them?
> 
> > That's really an open discussion, I don't yet have a clear idea on how
> > to handle that.
> >
> > Thomas
> > --
> > Thomas Petazzoni, CTO, Bootlin
> > Embedded Linux and Kernel engineering
> > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fboot
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