Hi Masahiro,
On 27 May 2014 01:32, Masahiro Yamada yamada.m@jp.panasonic.com wrote:
Hi.
I've posted two sets of Kconfig RFC patches: "RFCv2a" and "RFCv2b"
The difference from v1 is that Full U-boot image, SPL and TPL share a single defconfig and "make config" is done in one-shot.
This approach dates back to Simon's following comments:
On Thu, 20 Mar 2014 19:15:30 -0700 Simon Glass sjg@chromium.org wrote:
But, our situation is a little more complicated. We need to generate 3 images at most: main image, SPL and TPL. And each of them can have a different set of CONFIGs.
For example, we can describe a board header file like this:
#if defined(CONFIG_TPL_BUILD) # define CONFIG_FOO 100 #elif defined(CONFIG_SPL_BUILD) # define CONFIG_FOO 50 #else # define CONFIG_FOO 10 # define CONFIG_BAR #endif
I wonder if we should drop this, and require that all have the same options? That would involve requiring that board config files are not permitted to use #ifdef CONFIG_SPL or #ifdef CONFIG_TPL.
Does that seem like a bad restriction? The advantage is that we only need one defconfig for each board. It seems to me that things are going to get really painful if we have three different configs.
Of course, this doesn't preclude #ifdefs in the Makefiles or actual source code, but we already have SPL-specific feature options.
I'm not 100% clear on the constraints here.
In my opition, this approach might work, but will be painful.
Anyway I just wanted to see what would happen if multiple binary images had a single defconfig in common.
We will have to duplicate many configs with CONFIG_SPL_ and CONFIG_TPL_ prefixes.
For example,
CONFIG_SYS_TEXT_BASE (text base for the full image)
CONFIG_SPL_TEXT_BASE (text base for SPL)
CONFIG_TPL_TEXT_BASE (text base for TPL)
CONFIG_OF_CONTROL (enables OF control for the full image)
CONFIG_SPL_OF_CONTROL (enables OF control for SPL)
CONFIG_TPL_OF_CONTROL (enables OF control for TPL)
Probably I will not adopt this approach, but your comments are welcome.
I have been thinking about this a lot, but it isn't 100% clear to me.
While I agree that duplicating the CONFIGs is bad, in fact the opposite of what I was getting at, I do feel that things like CONFIG_TEGRA20 need to be set in one place. We don't want the SPL/TPL config to be changing things that make no sense given the board that is selected. It doesn't make sense to have an SPL for Tegra and a TPL for MX6.
Similar to what Tom was saying I feel that there will come a time when the difference between U-Boot and SPL is just the options that are enabled - the code paths will be the same. For example, I did a CONFIG_CMD series which removed all commands from U-Boot and cut the size to <50KB. OK that is not SPL size, but I can see a point where they will merge. In that case we certainly don't want the option that you list above - instead we want CONFIG_OF_CONTROL to mean the same thing for U-Boot and SPL.
Perhaps it will help if we can have options like:
make menuconfig_main make menuconfig_spl make menuconfig_tpl
to avoid chaining between configs? That was my main concern with series 1.
[snip]
It would be great if we could make a decision on this and merge it soon. To me the ARCH issue is minor but FWIW I think we should try to avoid needing ARCH= on the command line.
So long as we get the general direction right we can make changes later. To me the general direction is towards getting rid of the special-case SPL code and SPL options.
Anyone else have comments?
Regards, Simon