[U-Boot] litesom.c: Board stuff in SOC ?
Hi Marcin,
even if it was already merged (and maybe I am guilty of it because I have not noted before), it is completely crazy that a board is stored inside the SOC directory. The litesom board is in fact in ./arch/arm/cpu/armv7/mx6/litesom.c, and there is nothing that justify this. The code has just board related stuff and nothing common for all SOC.
I just took again the commit and I see:
Moving arch/arm/mach-litesom/ to arch/arm/cpu/armv7/mx6/ was requested in [1] during discussion of chiliSOM support patches.
[1] http://lists.denx.de/pipermail/u-boot/2017-January/279137.html
But [1] has nothing to do with the context. I will tend to revert this patch and wait for an appropriate patch that add support for the board just like all other boards in U-Boot - as it is currently, it is wrong.
Regards, Stefano
Hi Stefano,
On 18.05.2017 16:28, Stefano Babic wrote:
Hi Marcin,
even if it was already merged (and maybe I am guilty of it because I have not noted before), it is completely crazy that a board is stored inside the SOC directory. The litesom board is in fact in ./arch/arm/cpu/armv7/mx6/litesom.c, and there is nothing that justify this. The code has just board related stuff and nothing common for all SOC.
litesom is not a board, but a SOM. It has only RAM and eMMC memory included with the processor. litesom cannot work on it's own. It needs to be part of some board. An example board is liteboard, which support is included in board/grinn/liteboard/. Please visit [2] to visualize what the litesom device is.
The idea about creating a separate file in arch/arm/cpu/armv7/mx6/ was to be able to reuse code when new boards, that use litesom as it's core, will be added. And these boards need not to be manufactured or designed by Grinn. So if some other vendor wants to add support for it's board (which will be based on litesom), the code to initialize RAM and eMMC can be reused. When litesom code would be part of board/grinn/ directory, then other vendors could not easily add support for their boards without copying litesom sources.
[2] http://grinn-global.com/litesom/
I just took again the commit and I see:
Moving arch/arm/mach-litesom/ to arch/arm/cpu/armv7/mx6/ was requested in [1] during discussion of chiliSOM support patches.
[1] http://lists.denx.de/pipermail/u-boot/2017-January/279137.html
But [1] has nothing to do with the context. I will tend to revert this patch and wait for an appropriate patch that add support for the board just like all other boards in U-Boot - as it is currently, it is wrong.
Link [1] was a discussion of adding chilisom support into u-boot. The idea was the same - allow to reuse SOM code for vendors creating their own board based on our SOMs.
Regards, Marcin
Regards, Stefano
Hi Marcin,
On 18/05/2017 16:57, Marcin Niestroj wrote:
Hi Stefano,
On 18.05.2017 16:28, Stefano Babic wrote:
Hi Marcin,
even if it was already merged (and maybe I am guilty of it because I have not noted before), it is completely crazy that a board is stored inside the SOC directory. The litesom board is in fact in ./arch/arm/cpu/armv7/mx6/litesom.c, and there is nothing that justify this. The code has just board related stuff and nothing common for all SOC.
litesom is not a board, but a SOM.
It does not matter, sorry. The code is not common for all boards (and if you like it, all SOMs) sharing the same SOC or SOC family. In this case, i.MX6.
There is plenty of such as example in U-Boot, please check it in code. SOM support is in the boards directory and it must not be here. It will be removed.
It has only RAM and eMMC memory included with the processor.
Like all SOMs you find in u-boot from a lot of different vendors...just check it.
litesom cannot work on it's own. It needs to be part of some board. An example board is liteboard, which support is included in board/grinn/liteboard/. Please visit [2] to visualize what the litesom device is.
Thanks, nothing new.
Again: the SOM is specific to a vendor and cannot be in the SOC directory. There should be then a board/grinn/common (or whatever you want) where SOM code is put. And again, not in SOC directory.
The idea about creating a separate file in arch/arm/cpu/armv7/mx6/
The idea is correct, just in wrong place. There are plenty of examples doing this:
./engicam/common ./freescale/common ./compulab/common
.... and many others.
was to be able to reuse code when new boards, that use litesom as it's core, will be added. And these boards need not to be manufactured or designed by Grinn.
Right, so why are we discussing ? They belong to grinn, that means the code should be in board/<vendor>, that is board/grinn. Please move it !
So if some other vendor wants to add support for it's board (which will be based on litesom), the code to initialize RAM and eMMC can be reused.
They will be put code into the grimm directory. See all other vendors selling SOMs.
When litesom code would be part of board/grinn/ directory, then other vendors could not easily add support for their boards without copying litesom sources.
I will take care that the code will not be duplicated - not worry.
Please move it or it will be removed, thanks !
[2] http://grinn-global.com/litesom/
I just took again the commit and I see:
Moving arch/arm/mach-litesom/ to arch/arm/cpu/armv7/mx6/ was requested in [1] during discussion of chiliSOM support patches.
[1] http://lists.denx.de/pipermail/u-boot/2017-January/279137.html
But [1] has nothing to do with the context. I will tend to revert this patch and wait for an appropriate patch that add support for the board just like all other boards in U-Boot - as it is currently, it is wrong.
Link [1] was a discussion of adding chilisom support into u-boot. The idea was the same - allow to reuse SOM code for vendors creating their own board based on our SOMs.
Idea is already used in U-Boot and the SOM vendor has priority. Else code inside arch/arm/cpu/*, that must be common to all boards and *all* SOMs using those processor is becoming a mess. Please move it.
Best regards, Stefano
Hi Stefano,
I've added Tom to the discussion. So if we make some changes to SOM code position in u-boot tree, let's make sure we do it for all architectures the same (at least I mean chilisom code which is in arch/arm/mach-omap2/am33xx/).
On 18.05.2017 17:20, Stefano Babic wrote:
Hi Marcin,
On 18/05/2017 16:57, Marcin Niestroj wrote:
Hi Stefano,
On 18.05.2017 16:28, Stefano Babic wrote:
Hi Marcin,
even if it was already merged (and maybe I am guilty of it because I have not noted before), it is completely crazy that a board is stored inside the SOC directory. The litesom board is in fact in ./arch/arm/cpu/armv7/mx6/litesom.c, and there is nothing that justify this. The code has just board related stuff and nothing common for all SOC.
litesom is not a board, but a SOM.
It does not matter, sorry. The code is not common for all boards (and if you like it, all SOMs) sharing the same SOC or SOC family. In this case, i.MX6.
There is plenty of such as example in U-Boot, please check it in code. SOM support is in the boards directory and it must not be here. It will be removed.
It has only RAM and eMMC memory included with the processor.
Like all SOMs you find in u-boot from a lot of different vendors...just check it.
litesom cannot work on it's own. It needs to be part of some board. An example board is liteboard, which support is included in board/grinn/liteboard/. Please visit [2] to visualize what the litesom device is.
Thanks, nothing new.
Again: the SOM is specific to a vendor and cannot be in the SOC directory. There should be then a board/grinn/common (or whatever you want) where SOM code is put. And again, not in SOC directory.
The idea about creating a separate file in arch/arm/cpu/armv7/mx6/
The idea is correct, just in wrong place. There are plenty of examples doing this:
./engicam/common
Ok, I see. But it was just merged, so I couldn't look at it earlier. As I understand, you want me to follow this example with litesom.
I do not say that is a bad idea in general and we should not follow it. *BUT* right now these sources cannot be used when other vendor will create it's own board. They won't compile, because root Makefile has a "libs-$(HAVE_VENDOR_COMMON_LIB) += board/$(VENDOR)/common/" entry, which depends on *board* vendor.
./freescale/common
There is a lot of shared code between freescale boards, but I do not see SOM example there. Could you point me one?
./compulab/common
I do not see SOM code there. There is also ./compulab/cl-som-am57x directory, but it contains *board* support code, which uses CL-SOM-AM57x, not pure SOM (e.g. they configure UART and SD card, which are not SOM specific).
.... and many others.
was to be able to reuse code when new boards, that use litesom as it's core, will be added. And these boards need not to be manufactured or designed by Grinn.
Right, so why are we discussing ? They belong to grinn, that means the code should be in board/<vendor>, that is board/grinn. Please move it !
So if some other vendor wants to add support for it's board (which will be based on litesom), the code to initialize RAM and eMMC can be reused.
They will be put code into the grimm directory. See all other vendors selling SOMs.
When litesom code would be part of board/grinn/ directory, then other vendors could not easily add support for their boards without copying litesom sources.
I will take care that the code will not be duplicated - not worry.
Ok. Could you tell me how that would be done? That is my main concern about moving SOM sources to ./board/<vendor>/common. In fact I've already asked about that in both RFC for adding lite(som/board) [3] [4] and described my motivation in PATCH adding lite(som/board) [5] support in u-boot.
[3] https://lists.denx.de/pipermail/u-boot/2016-August/265384.html [4] https://lists.denx.de/pipermail/u-boot/2016-September/266534.html [5] https://lists.denx.de/pipermail/u-boot/2016-September/266799.html
Please move it or it will be removed, thanks !
[2] http://grinn-global.com/litesom/
I just took again the commit and I see:
Moving arch/arm/mach-litesom/ to arch/arm/cpu/armv7/mx6/ was requested in [1] during discussion of chiliSOM support patches.
[1] http://lists.denx.de/pipermail/u-boot/2017-January/279137.html
But [1] has nothing to do with the context. I will tend to revert this patch and wait for an appropriate patch that add support for the board just like all other boards in U-Boot - as it is currently, it is wrong.
Link [1] was a discussion of adding chilisom support into u-boot. The idea was the same - allow to reuse SOM code for vendors creating their own board based on our SOMs.
Idea is already used in U-Boot and the SOM vendor has priority. Else code inside arch/arm/cpu/*, that must be common to all boards and *all* SOMs using those processor is becoming a mess. Please move it.
I do not oppose to move SOM sources from arch/arm/cpu/*, but in my opinion we need some mechanism for reusing SOM code for all board vendors before doing so.
Hi Marcin,
On 19/05/2017 12:41, Marcin Niestroj wrote:
Hi Stefano,
I've added Tom to the discussion.
Of course !
So if we make some changes to SOM code position in u-boot tree, let's make sure we do it for all architectures the same
We have already not done in this way. We have all boards / SOM code inside bords/, the only exceptions are yours. If there is a decision to add an abstraction for SOM, we have to put coherently all SOMs that are now stored in the boards directory.
What you mention are just exception - that I would like to clean up.
Best regards, Stefano Babic
(at least I mean chilisom code which is in arch/arm/mach-omap2/am33xx/
On 18.05.2017 17:20, Stefano Babic wrote:
Hi Marcin,
On 18/05/2017 16:57, Marcin Niestroj wrote:
Hi Stefano,
On 18.05.2017 16:28, Stefano Babic wrote:
Hi Marcin,
even if it was already merged (and maybe I am guilty of it because I have not noted before), it is completely crazy that a board is stored inside the SOC directory. The litesom board is in fact in ./arch/arm/cpu/armv7/mx6/litesom.c, and there is nothing that justify this. The code has just board related stuff and nothing common for all SOC.
litesom is not a board, but a SOM.
It does not matter, sorry. The code is not common for all boards (and if you like it, all SOMs) sharing the same SOC or SOC family. In this case, i.MX6.
There is plenty of such as example in U-Boot, please check it in code. SOM support is in the boards directory and it must not be here. It will be removed.
It has only RAM and eMMC memory included with the processor.
Like all SOMs you find in u-boot from a lot of different vendors...just check it.
litesom cannot work on it's own. It needs to be part of some board. An example board is liteboard, which support is included in board/grinn/liteboard/. Please visit [2] to visualize what the litesom device is.
Thanks, nothing new.
Again: the SOM is specific to a vendor and cannot be in the SOC directory. There should be then a board/grinn/common (or whatever you want) where SOM code is put. And again, not in SOC directory.
The idea about creating a separate file in arch/arm/cpu/armv7/mx6/
The idea is correct, just in wrong place. There are plenty of examples doing this:
./engicam/common
Ok, I see. But it was just merged, so I couldn't look at it earlier. As I understand, you want me to follow this example with litesom.
I do not say that is a bad idea in general and we should not follow it. *BUT* right now these sources cannot be used when other vendor will create it's own board. They won't compile, because root Makefile has a "libs-$(HAVE_VENDOR_COMMON_LIB) += board/$(VENDOR)/common/" entry, which depends on *board* vendor.
./freescale/common
There is a lot of shared code between freescale boards, but I do not see SOM example there. Could you point me one?
./compulab/common
I do not see SOM code there. There is also ./compulab/cl-som-am57x directory, but it contains *board* support code, which uses CL-SOM-AM57x, not pure SOM (e.g. they configure UART and SD card, which are not SOM specific).
.... and many others.
was to be able to reuse code when new boards, that use litesom as it's core, will be added. And these boards need not to be manufactured or designed by Grinn.
Right, so why are we discussing ? They belong to grinn, that means the code should be in board/<vendor>, that is board/grinn. Please move it !
So if some other vendor wants to add support for it's board (which will be based on litesom), the code to initialize RAM and eMMC can be reused.
They will be put code into the grimm directory. See all other vendors selling SOMs.
When litesom code would be part of board/grinn/ directory, then other vendors could not easily add support for their boards without copying litesom sources.
I will take care that the code will not be duplicated - not worry.
Ok. Could you tell me how that would be done? That is my main concern about moving SOM sources to ./board/<vendor>/common. In fact I've already asked about that in both RFC for adding lite(som/board) [3] [4] and described my motivation in PATCH adding lite(som/board) [5] support in u-boot.
[3] https://lists.denx.de/pipermail/u-boot/2016-August/265384.html [4] https://lists.denx.de/pipermail/u-boot/2016-September/266534.html [5] https://lists.denx.de/pipermail/u-boot/2016-September/266799.html
Please move it or it will be removed, thanks !
[2] http://grinn-global.com/litesom/
I just took again the commit and I see:
Moving arch/arm/mach-litesom/ to arch/arm/cpu/armv7/mx6/ was requested in [1] during discussion of chiliSOM support patches.
[1] http://lists.denx.de/pipermail/u-boot/2017-January/279137.html
But [1] has nothing to do with the context. I will tend to revert this patch and wait for an appropriate patch that add support for the board just like all other boards in U-Boot - as it is currently, it is wrong.
Link [1] was a discussion of adding chilisom support into u-boot. The idea was the same - allow to reuse SOM code for vendors creating their own board based on our SOMs.
Idea is already used in U-Boot and the SOM vendor has priority. Else code inside arch/arm/cpu/*, that must be common to all boards and *all* SOMs using those processor is becoming a mess. Please move it.
I do not oppose to move SOM sources from arch/arm/cpu/*, but in my opinion we need some mechanism for reusing SOM code for all board vendors before doing so.
On Fri, May 19, 2017 at 12:51:18PM +0200, Stefano Babic wrote:
Hi Marcin,
On 19/05/2017 12:41, Marcin Niestroj wrote:
Hi Stefano,
I've added Tom to the discussion.
Of course !
So if we make some changes to SOM code position in u-boot tree, let's make sure we do it for all architectures the same
We have already not done in this way. We have all boards / SOM code inside bords/, the only exceptions are yours. If there is a decision to add an abstraction for SOM, we have to put coherently all SOMs that are now stored in the boards directory.
What you mention are just exception - that I would like to clean up.
So, we do have a problem with the layout today. The point of SOMs is that yes, you can drop them into a carrier from the same vendor (and this is true for both "3rd party" ones like litesom/chilisom/solidrun/etc and vendor ones like more recent NXP eval boards) or company X buys the SOMs and puts them in their own custom carrier (which hell, we have customers that do). In the latter case, it doesn't make sense for company X to put their board in boards/SOM-vendor/.
In my mind, arch/arm/mach-omap2/am33xx/chilisom.c is the right solution and the big problem with i.MX right now is that arch/arm/imx-common and arch/arm/cpu/armv7/mx* need to get some re-organization under arch/arm/mach-imx/. And I'm not going to claim that arch/arm/mach-omap2 is best organized here, I largely moved the old omap-common to mach-omap2 and everything else into subdirs of that. I can certainly see an argument for arch/arm/mach-$X/som/ (or mach-$X/$soc/som/) instead of just putting them in arch/arm/mach-$X/ (or again, mach-$X/$soc/).
Thanks!
Hi Tom,
On 19/05/2017 15:39, Tom Rini wrote:
On Fri, May 19, 2017 at 12:51:18PM +0200, Stefano Babic wrote:
Hi Marcin,
On 19/05/2017 12:41, Marcin Niestroj wrote:
Hi Stefano,
I've added Tom to the discussion.
Of course !
So if we make some changes to SOM code position in u-boot tree, let's make sure we do it for all architectures the same
We have already not done in this way. We have all boards / SOM code inside bords/, the only exceptions are yours. If there is a decision to add an abstraction for SOM, we have to put coherently all SOMs that are now stored in the boards directory.
What you mention are just exception - that I would like to clean up.
So, we do have a problem with the layout today.
Indeed, true. There is not an abstraction for SOM today.
The point of SOMs is that yes, you can drop them into a carrier from the same vendor (and this is true for both "3rd party" ones like litesom/chilisom/solidrun/etc and vendor ones like more recent NXP eval boards) or company X buys the SOMs and puts them in their own custom carrier (which hell, we have customers that do).
Right, this is the common case.
In the latter case, it doesn't make sense for company X to put their board in boards/SOM-vendor/.
The question is how they reference to the common / SOM code. I am quite sure that the object should be part of the board library, that is at the end part of board/<vendor>/<board name>/lib.a.
In my mind, arch/arm/mach-omap2/am33xx/chilisom.c is the right solution and the big problem with i.MX right now is that arch/arm/imx-common and arch/arm/cpu/armv7/mx* need to get some re-organization under arch/arm/mach-imx/.
Sure the SOM code should be not under cpu/....mx6. This is wrong.
imx-common was created (as far as I can still remember) as solution to put code shared between all i.MX processors, from imx.2x up to i.MX6 or i.MX7. Code that does not belong to a single SOC.
As far as I see, there is not a single solution for SOM in u-boot. In some cases (what you mention) are in mach-*, in some other cases they are under board/<vendor>. Just check the number of "common" directories under boards. In most cases they are SOM, and I am sure I am still missing a lot of them.
And I'm not going to claim that arch/arm/mach-omap2 is best organized here, I largely moved the old omap-common to mach-omap2 and everything else into subdirs of that.
Nevertheless, this is a much more sustainable solution. If imx-common is changed into mach-imx, and it contains subdirectories for the specific type, we could simplify imx-common/Makefile, that is become messy with two many filters in a way as in mach-omap2. And then, moving litesom.c in a place as arch/arm/mach-imx/som/mx6 seems much more appropriate.
I can certainly see an argument for arch/arm/mach-$X/som/ (or mach-$X/$soc/som/) instead of just putting them in arch/arm/mach-$X/ (or again, mach-$X/$soc/).
mach-$X/$soc/som/ is my preferred choice if we vote.. :-)
Best regards, Stefano
On Fri, May 19, 2017 at 04:13:29PM +0200, Stefano Babic wrote:
Hi Tom,
On 19/05/2017 15:39, Tom Rini wrote:
On Fri, May 19, 2017 at 12:51:18PM +0200, Stefano Babic wrote:
Hi Marcin,
On 19/05/2017 12:41, Marcin Niestroj wrote:
Hi Stefano,
I've added Tom to the discussion.
Of course !
So if we make some changes to SOM code position in u-boot tree, let's make sure we do it for all architectures the same
We have already not done in this way. We have all boards / SOM code inside bords/, the only exceptions are yours. If there is a decision to add an abstraction for SOM, we have to put coherently all SOMs that are now stored in the boards directory.
What you mention are just exception - that I would like to clean up.
So, we do have a problem with the layout today.
Indeed, true. There is not an abstraction for SOM today.
The point of SOMs is that yes, you can drop them into a carrier from the same vendor (and this is true for both "3rd party" ones like litesom/chilisom/solidrun/etc and vendor ones like more recent NXP eval boards) or company X buys the SOMs and puts them in their own custom carrier (which hell, we have customers that do).
Right, this is the common case.
In the latter case, it doesn't make sense for company X to put their board in boards/SOM-vendor/.
The question is how they reference to the common / SOM code. I am quite sure that the object should be part of the board library, that is at the end part of board/<vendor>/<board name>/lib.a.
I am less concerned with "board" vs "arch" than I am with making it clearly and easily re-usable, but also not adding further complex Makefile logic to handle inclusion.
In my mind, arch/arm/mach-omap2/am33xx/chilisom.c is the right solution and the big problem with i.MX right now is that arch/arm/imx-common and arch/arm/cpu/armv7/mx* need to get some re-organization under arch/arm/mach-imx/.
Sure the SOM code should be not under cpu/....mx6. This is wrong.
So we agree, good, yes, OK :)
imx-common was created (as far as I can still remember) as solution to put code shared between all i.MX processors, from imx.2x up to i.MX6 or i.MX7. Code that does not belong to a single SOC.
As far as I see, there is not a single solution for SOM in u-boot. In some cases (what you mention) are in mach-*, in some other cases they are under board/<vendor>. Just check the number of "common" directories under boards. In most cases they are SOM, and I am sure I am still missing a lot of them.
Well, I think the answer is that arch/arm/imx-common/ needs to become arch/arm/mach-imx (ala the kernel) and arch/arm/cpu/armv7/mx* needs to move to this new directory, in whatever layout you feel is cleanest (the kernel has this flat, except for include/mach). I don't know if I was clear enough in my first reply, so I'm following up here, now.
And I'm not going to claim that arch/arm/mach-omap2 is best organized here, I largely moved the old omap-common to mach-omap2 and everything else into subdirs of that.
Nevertheless, this is a much more sustainable solution. If imx-common is changed into mach-imx, and it contains subdirectories for the specific type, we could simplify imx-common/Makefile, that is become messy with two many filters in a way as in mach-omap2. And then, moving litesom.c in a place as arch/arm/mach-imx/som/mx6 seems much more appropriate.
Yeah, there's a little bit of clean-up I want to do to that Makefile at some point and partly relies on adding more Kconfig symbols and merging more of the common-IP-different-src things we still have. But that's another story...
I can certainly see an argument for arch/arm/mach-$X/som/ (or mach-$X/$soc/som/) instead of just putting them in arch/arm/mach-$X/ (or again, mach-$X/$soc/).
mach-$X/$soc/som/ is my preferred choice if we vote.. :-)
Make it so in mach-imx and we'll move from there :) Thanks!
participants (3)
-
Marcin Niestroj -
Stefano Babic -
Tom Rini