BCM2835 (used on Raspberry Pi) and BCM2836 (used on Raspberry Pi 2)
are similar enough. One of the biggest differences is the ARM
processor. It is reasonable to collect the source files into a
single place, arch/arm/mach-bcm283x/.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
My main motivations for this commit are:
[1] Follow the arch/arm/Makefile style of Linux Kernel
[2] Maintain compiler options systematically
Currently, we give -march=* and -mtune=* options inconsistently:
Only some of the CPUs pass -march=* and -mtune=* options.
By collecting such options into the single place arch/arm/Makefile
we can tell which options are missing at a glance.
[3] Prepare for deprecating arch/*/cpu/*/config.mk
Note:
This commit just moves the compiler options so as not to change
the behavior at all. It does not care about the correctness of
the given options. Fox example, "-march=armv5te" might be better
than "-march=armv4" for ARM946EJS, but it is beyond the scope this
commit. Also, filling the missing -march=* and -tune=* is left
to follow-up patches.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
This commit adds $(srctree)/arch/arm/$(machdirs)/include/mach to
the headers search path.
It allows us to replace "#include <asm/arch/foo.h>" with
"#include <mach/foo.h>". As "#include <asm/arch/foo.h>" is still
supported, we can modify each file one by one.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Move
arch/arm/cpu/arm926ejs/kirkwood/* -> arch/arm/mach-kirkwood/*
Note:
Perhaps, can we merge arch/arm/mach-kirkwood and
arch/arm/mvebu-common into arch/arm/mach-mvebu, like Linux?
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Stefan Roese <sr@denx.de>
Cc: Prafulla Wadaskar <prafulla@marvell.com>
Cc: Luka Perkov <luka.perkov@sartura.hr>
In U-boot, the directory structure, arch/$(ARCH)/cpu/$(CPU)/$(SOC)/
has been adopted except that $(CPU) is missing from some
architectures and $(SOC) is missing from some CPUs.
This structure did not fit very well in some cases.
[1] AT91
AT91 SoC family have been developed across some ARM processor
generations. Generally speaking, some IPs are often re-used in the
same SoC family (same SoC vendor) even when the main processor is
updated. As a result, a SoC-common directory is needed in the upper
level. Currently, AT91 source files are placed as follows:
arch/arm/cpu/arm920t/at91/*
arch/arm/cpu/arm926ejs/at91/*
arch/arm/cpu/armv7/at91/*
arch/arm/cpu/at91-common/*
Once directories are split, the motivation for refactorings across
CPU directories is lost. Some files in arm920t/at91/ and
arm926ejs/at91/ are so similar that they could be merged.
[2] Tegra
Tegra is a little bit special case where different CPUs are used for
SPL and the main U-boot. To obey the arch/$(ARCH)/cpu/$(CPU)/$(SOC)
structure, the source files must be placed across the CPUs,
again SoC-common directory is necessary in the upper level.
Moreover, there are several families in Tegra: Tegra20, Tegra30,
Tegra114, Tegra124. Here again, the tegra-common directory is needed
to contain commonly-used files.
Tegra directories have been sprinkled in the directory structure.
arch/arm/cpu/arm720t/tegra20
arch/arm/cpu/arm720t/tegra30
arch/arm/cpu/arm720t/tegra114
arch/arm/cpu/arm720t/tegra124
arch/arm/cpu/arm720t/tegra-common
arch/arm/cpu/armv7/tegra20
arch/arm/cpu/armv7/tegra30
arch/arm/cpu/armv7/tegra114
arch/arm/cpu/armv7/tegra124
arch/arm/cpu/armv7/tegra-common
arch/arm/cpu/tegra20-common
arch/arm/cpu/tegra30-common
arch/arm/cpu/tegra114-common
arch/arm/cpu/tegra124-common
arch/arm/cpu/tegra-common
As you see, splitting SoC code by the CPU is not going well,
especially for ARM.
Why don't we collect SoC-specific files into a single place?
A good example we can follow is Linux's arch/arm/mach-* structure.
This item was discussed in the following thread:
http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/188548/
Looks like I got some positive responses and we are almost ready to
start this movement.
This commit prepares arch/arm/Makefile for describing machdirs in it.
After this commit, we can move SoC directory to arch/arm/mach-$(SOC)
in simple steps although some cases such as AT91 and Tegra need more
fixes.
What we generally have to do is:
[1] Move files arch/arm/cpu/$(CPU)/$(SOC)/* to arch/arm/mach-$(SOC)/*
[2] Add machine entry into arch/arm/Makefile
[3] Remove "obj-y += $(SOC)" from arch/arm/cpu/$(CPU)/Makefile
[4] Fix the Kconfig file path in arch/arm/Kconfig
[5] Modify MAINTAINERS if necessary
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Introduce a Makefile under arch/$ARCH/ and include it in the
top Makefile (similar to Linux kernel). This allows further
refactoringi like moving architecture-specific code out of global
makefiles, deprecating config variables (CPU, CPUDIR, SOC) or
deprecating arch/$ARCH/config.mk.
In contrary to Linux kernel, U-Boot defines the ARCH variable by
Kconfig, thus the arch Makefile can only included conditionally
after the top config.mk.
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Acked-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
