[U-Boot] [PATCH 1/4] common: imx: Implement generic u-boot.nand target

[Benoît Thébaudeau]

Hi Tom,

On Thursday, February 28, 2013 12:47:46 AM, Benoît Thébaudeau wrote:
> Hi Tom,
> 
> On Thursday, February 28, 2013 12:44:28 AM, Tom Rini wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> > 
> > On 02/27/2013 05:18 PM, Benoît Thébaudeau wrote:
> > > Hi Marek,
> > > 
> > > On Monday, February 25, 2013 7:19:54 PM, Marek Vasut wrote:
> > >> Implement u-boot.nand target that can be reused with a small
> > >> amount of churn across all CPU models. The idea is to delegate
> > >> the u-boot.nand target out of the main Makefile and into the
> > >> CPU's Makefile (very similar to what u-boot.imx does now). The
> > >> main Makefile shall only contain path to which the u-boot.nand
> > >> target is delegated. Hopefully this will not produce too much
> > >> bloat in the main Makefile.
> > >> 
> > >> To demonstrate this implementation, add u-boot.nand target for
> > >> i.MX53.
> > >> 
> > >> Signed-off-by: Marek Vasut <marex at denx.de> Cc: Benoît Thébaudeau
> > >> <benoit.thebaudeau at advansee.com> Cc: Fabio Estevam
> > >> <fabio.estevam at freescale.com> Cc: Stefano Babic <sbabic at denx.de>
> > >> --- Makefile                     |   18 ++++++++++++++++++
> > >> arch/arm/imx-common/Makefile |    6 ++++++ 2 files changed, 24
> > >> insertions(+)
> > >> 
> > >> diff --git a/Makefile b/Makefile index 41054b7..8b1010a 100644
> > >> --- a/Makefile +++ b/Makefile @@ -470,6 +470,23 @@
> > >> $(obj)u-boot.img:	$(obj)u-boot.bin $(obj)u-boot.imx:
> > >> $(obj)u-boot.bin depend $(MAKE) -C $(SRCTREE)/arch/arm/imx-common
> > >> $(obj)u-boot.imx
> > >> 
> > >> +# +# Generic u-boot.nand target. +# +# Every CPU that needs
> > >> u-boot.nand must add a path to an implementation of +# the actual
> > >> u-boot.nand generator below. +# +ifdef CONFIG_MX53
> > >> +CONFIG_NAND_TRG_PATH := $(SRCTREE)/arch/arm/imx-common +endif +
> > >> +$(obj)u-boot.nand: $(obj)u-boot.bin depend +		if [
> > >> "X$(CONFIG_NAND_TRG_PATH)X" = "XX" ] ; then		\ +			echo "This CPU
> > >> does not support u-boot.nand target!" ;	\ +			exit 1 ;						\ +
> > >> fi +		$(MAKE) -C $(CONFIG_NAND_TRG_PATH) $(obj)u-boot.nand +
> > >> $(obj)u-boot.kwb:       $(obj)u-boot.bin $(obj)tools/mkimage -n
> > >> $(CONFIG_SYS_KWD_CONFIG) -T kwbimage \ -a $(CONFIG_SYS_TEXT_BASE)
> > >> -e $(CONFIG_SYS_TEXT_BASE) -d $< $@ @@ -857,6 +874,7 @@ clobber:
> > >> tidy @rm -f $(obj)u-boot.kwb @rm -f $(obj)u-boot.pbl @rm -f
> > >> $(obj)u-boot.imx +	@rm -f $(obj)u-boot.nand @rm -f
> > >> $(obj)u-boot.ubl @rm -f $(obj)u-boot.ais @rm -f $(obj)u-boot.dtb
> > >> diff --git a/arch/arm/imx-common/Makefile
> > >> b/arch/arm/imx-common/Makefile index 5d5c5b2..71ea36f 100644 ---
> > >> a/arch/arm/imx-common/Makefile +++
> > >> b/arch/arm/imx-common/Makefile @@ -50,6 +50,12 @@
> > >> $(obj)u-boot.imx: $(OBJTREE)/u-boot.bin $(OBJTREE)/$(patsubst
> > >> "%",%,$(CONFIG_IMX $(OBJTREE)/tools/mkimage -n $(filter-out
> > >> %.bin,$^) -T imximage \ -e $(CONFIG_SYS_TEXT_BASE) -d $< $@
> > >> 
> > >> +$(obj)u-boot.nand: $(obj)u-boot.imx +	(								\ +		echo -ne
> > >> '\x00\x00\x00\x00\x46\x43\x42\x20\x01' ;	\
> > > ^ It does not work in my environment (Ubuntu 12.10). -ne is
> > > interpreted as text, so the FCB is broken. This is because /bin/sh
> > > (set to dash) is invoked by default on my machine here. It would
> > > work with the /bin/bash set by the main Makefile for SHELL, but
> > > this is not passed to the sub-make.
> > > 
> > > So what do you think we should do: 1) Add "export SHELL" to the
> > > main Makefile? 2) Move the SHELL assignment from the main Makefile
> > > to the top-level config.mk? 3) Set "SHELL=$(SHELL)" on the command
> > > line when invoking the sub-make? 4) Use printf instead of echo? 5)
> > > Something else?
> > > 
> > > I like 1). Do you see possible side effects?
> > 
> > It looks like in these cases the kernel does $(shell echo -...), or is
> > that also not working on your setup?
> 
> I'll test that tomorrow, but I don't see how it could work better since
> $(shell ...) will very likely invoke $(SHELL) -c "...".
> 
> /bin/echo works though, but is this portable enough for U-Boot?

No, your suggestion does not work on my setup.

I've looked at what Linux does, and this is not what you said: When it uses
$(shell echo -...), this is not to make the arguments work, but this is because
$(shell ...) is required in the context, e.g. for make variable assignments or
conditional parts of Makefiles.

U-Boot sets SHELL in its main Makefile and does not export it, whereas Linux
sets CONFIG_SHELL and exports it, using it explicitly.

Best regards,
Benoît