Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Simon, On 08/01/12 09:39, Simon Glass wrote: Hi Gururaja, On Thu, Jan 5, 2012 at 11:25 PM, Hebbar, Gururaja gururaja.heb...@ti.com wrote: On Fri, Jan 06, 2012 at 12:05:40, Wolfgang Denk wrote: Dear Hebbar, Gururaja, [snip] _after_ the list has been created - If this breaks dependencies that's your problem ;). It is up to you as the 'skipper' to make sure that you add init functions to allow things to still work Won't this lead to lots of code duplication across all boards, archs. So, tomorrow someone else will send a patch removing duplicate and merging it to a common place. I don't see why that would happen? I see no intention nor any need for duplicated code. So, every board, even under same arch, needs to define its own *complete-set* of INIT_CALL api's. I am dreaming about a lot of MB getting added to u-boot src. What makes you think so? As mentioned before, the INIT_CALL code is to be added to each board file for each arch, soc. I was speaking of actual C Code. Every board needs serial, console, i2c and many other common code. Wont they increase u-boot source size (in actual c code size). Every Board Maintainer will have almost same x-lines-added in the U-Boot release statics/summary page. Kindly correct me if I am wrong. I hope I understand you correctly. The idea is that the init list is specified for the architecture (or hopefully soon for the whole of U-Boot). Boards only need to mess with it if they want to add / remove something. Hopefully most boards won't do much at all with the init sequence. Using the proposal, there is no 'architecture init sequence' like there is now. Instead, everything that needs to be initialised before the main loop simply states that fact be adding an instance of the INIT_FUNC macro which specifies: - The name of the function to be called - The type of init being performed (console, sdram, fpga etc) - What type(s) of inits need to be performed before the named function can be called - What type(s) of inits the named function needs to be called before A board can freely insert additional init steps by adding INIT_CALLs A board can override a 'standard' init step by adding SKIP_INIT and the replacement INIT_CALL Just a thought. Why don't split it to ARCH_INIT, BOARD_INIT,. Because it's not such an easy split. You can define such groups, like arch, SoC, board family, board. But you cannot initialize the system in such grous - instead, initialization will jump around heavily between these groups, in a sequence that needs to be well defined, and that is often diofferent from board to board. Correct. Then Board maintainer will mention ARCH_INIT, SKIP_ARCH_INIT, BOARD_INIT ... By this way, Board maintainer can make use of common init calls between ARCHs, SOCs and BOARDs. See above, which hopefully contains what you need. At the moment we have things like arch_cpu_init() and the like to do common init for an arch, soc. I think you are saying that the arch code should be able to add things to the init list without every board for that arch doing it explicitly. If so, then that's exactly what Well, the arch code already can thanks to the init sequence being encoded into arch/foo/lib/board.c The problem is what if the CPU needs additional init, or the SoC, or a single board that no other CPU/SoC/board under that arch needs? At the moment, the solution is a combination of over-rideable weak functions and #ifdefs Graeme's idea should achieve. The arch code will have several INITCALL() steps to achieve this. It actually lends itself quite well Not only the arch code, but any code that needs to initialise something prior to entering the main loop - This can include the arch, SoC, CPU, board, chipset, drivers, etc... So long term, we should see the mess that is the Ethernet and serial driver init code cleaned up because each driver can simply add an INIT_FUNC to this requirement. Any file can put an INITCALL() in the sequence and the collection tool / linker tidy things up at the end. The boards should only have to worry about what they want to add/change for their own narrow purposes. Exactly :) Regards, Graeme ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Gururaja, On Thu, Jan 5, 2012 at 11:25 PM, Hebbar, Gururaja gururaja.heb...@ti.com wrote: On Fri, Jan 06, 2012 at 12:05:40, Wolfgang Denk wrote: Dear Hebbar, Gururaja, [snip] _after_ the list has been created - If this breaks dependencies that's your problem ;). It is up to you as the 'skipper' to make sure that you add init functions to allow things to still work Won't this lead to lots of code duplication across all boards, archs. So, tomorrow someone else will send a patch removing duplicate and merging it to a common place. I don't see why that would happen? I see no intention nor any need for duplicated code. So, every board, even under same arch, needs to define its own *complete-set* of INIT_CALL api's. I am dreaming about a lot of MB getting added to u-boot src. What makes you think so? As mentioned before, the INIT_CALL code is to be added to each board file for each arch, soc. I was speaking of actual C Code. Every board needs serial, console, i2c and many other common code. Wont they increase u-boot source size (in actual c code size). Every Board Maintainer will have almost same x-lines-added in the U-Boot release statics/summary page. Kindly correct me if I am wrong. I hope I understand you correctly. The idea is that the init list is specified for the architecture (or hopefully soon for the whole of U-Boot). Boards only need to mess with it if they want to add / remove something. Hopefully most boards won't do much at all with the init sequence. Just a thought. Why don't split it to ARCH_INIT, BOARD_INIT,. Because it's not such an easy split. You can define such groups, like arch, SoC, board family, board. But you cannot initialize the system in such grous - instead, initialization will jump around heavily between these groups, in a sequence that needs to be well defined, and that is often diofferent from board to board. Correct. Then Board maintainer will mention ARCH_INIT, SKIP_ARCH_INIT, BOARD_INIT ... By this way, Board maintainer can make use of common init calls between ARCHs, SOCs and BOARDs. See above, which hopefully contains what you need. At the moment we have things like arch_cpu_init() and the like to do common init for an arch, soc. I think you are saying that the arch code should be able to add things to the init list without every board for that arch doing it explicitly. If so, then that's exactly what Graeme's idea should achieve. The arch code will have several INITCALL() steps to achieve this. It actually lends itself quite well to this requirement. Any file can put an INITCALL() in the sequence and the collection tool / linker tidy things up at the end. The boards should only have to worry about what they want to add/change for their own narrow purposes. Regards, Simon Best regards, Wolfgang Denk Regards, Gururaja ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Wolfgang,
On Wed, Jan 4, 2012 at 1:44 AM, Wolfgang Denk w...@denx.de wrote:
Dear Graeme,
In message 4f02da64.60...@gmail.com you wrote:
[snip]
INIT_FUNC(cpu_init_f, f, fred, blah, foo);
Generates the string:
f:cpu_init_f:fred:blah:foo
and we can parse each of the elf archives to obtain a list of string
pointers from the .initfuncs, extract the strings and process them to
generate the init arrays
and add:
/DISCARD/ : { *(.initfuncs*) }
to the linker script to throw away the strings
It's a tad ugly under the hood, but the output will be very clean
Does this sound like a plan?
Yes. Looks good to me.
One thing comes to mind: it would be nice if we can find a way that
the INIT_FUNC definitions behave similar to weak functions - if an
init_func can be redefined / overwritten / modified by board specific
code we eventually have a very nice way to get rid of the related
#ifdef's.
I have a thought on this. How about a SKIP_INIT macro. Here's the idea
using SDRAM as an example:
At the arch level you may have
INIT_FUNC(sdram_init, f, sdram, console,)
so sdram_init sets the sdram requisite and must be done after all
console requisites have been completed.
Now if a SoC or board has an init that must be done before SDRAM:
INIT_FUNC(pre_sdram_init, f, pre_sdram, , sdram)
So this sets the pre_sdram requisite, requires no other initialisation
before running and must happen before and sdram init functions are run
Now lets say the Soc or board has a unique sdram init function that
overrides the arch's sdram init. We could just use weak functions and
allow the SoC or board to override sdram_init. But what if the SoC or
board has additional pre-requisite (or post-requisite) init requirements?
So in the SoC or board file:
SKIP_INIT(sdram)
INIT_FUNC(board_sdram_init, f, board_sdram,pre_sdram,vreg,console, )
Using board_sdram versus sdram_init is cricital:
The init sequence build tool will first create the entire init sequence
including the functions marked as sdram and board_sdram. But after
building the arrays, it will strip out all the functions marked as sdram
init functions. The reason the entire list has to be build first is so the
functions that rely on sdram can be added without unmet prerequisite
errors.
Of course, if you use SKIP_INIT(foo), you need to make sure that any
replacement INIT_FUNC will do everything foo did to make your board work.
Interestingly, this allows the following:
INIT_FUNC(calc_relocation, fr, calc_reloc, sdram, )
INIT_FUNC(copy_uboot_to_ram, fr, copy_to_ram, calc_relocation, )
INIT_FUNC(do_elf_reloc_adjusments, fr, elf_reloc, copy_to_ram, )
INIT_FUNC(clear_bss, fr, clear_bss, calc_reloc, )
#ifdef CONFIG_SYS_SKIP_RELOCATION
SKIP_INIT(calc_reloc)
SKIP_INIT(copy_to_ram)
SKIP_INIT(elf_reloc)
#endif
So if CONFIG_SYS_SKIP_RELOCATION is defined, relocation is not performed,
but clear_bss still is
Regards,
Graeme
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Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Graham,
On Thu, Jan 5, 2012 at 2:18 PM, Graeme Russ graeme.r...@gmail.com wrote:
Hi Wolfgang,
On Wed, Jan 4, 2012 at 1:44 AM, Wolfgang Denk w...@denx.de wrote:
Dear Graeme,
In message 4f02da64.60...@gmail.com you wrote:
[snip]
INIT_FUNC(cpu_init_f, f, fred, blah, foo);
Generates the string:
f:cpu_init_f:fred:blah:foo
and we can parse each of the elf archives to obtain a list of string
pointers from the .initfuncs, extract the strings and process them to
generate the init arrays
and add:
/DISCARD/ : { *(.initfuncs*) }
to the linker script to throw away the strings
It's a tad ugly under the hood, but the output will be very clean
Does this sound like a plan?
Yes. Looks good to me.
One thing comes to mind: it would be nice if we can find a way that
the INIT_FUNC definitions behave similar to weak functions - if an
init_func can be redefined / overwritten / modified by board specific
code we eventually have a very nice way to get rid of the related
#ifdef's.
I have a thought on this. How about a SKIP_INIT macro. Here's the idea
using SDRAM as an example:
At the arch level you may have
INIT_FUNC(sdram_init, f, sdram, console,)
Gosh this email took a few readings :-)
Can we get rid of the 'f' parameter? If we invent a prerequisite
called 'relocated' or something like that, to act as a barrier, then
maybe the order can be defined just like any other function which
depends on being before or after something?
so sdram_init sets the sdram requisite and must be done after all
console requisites have been completed.
Now if a SoC or board has an init that must be done before SDRAM:
INIT_FUNC(pre_sdram_init, f, pre_sdram, , sdram)
So this sets the pre_sdram requisite, requires no other initialisation
before running and must happen before and sdram init functions are run
Now lets say the Soc or board has a unique sdram init function that
overrides the arch's sdram init. We could just use weak functions and
allow the SoC or board to override sdram_init. But what if the SoC or
board has additional pre-requisite (or post-requisite) init requirements?
So in the SoC or board file:
SKIP_INIT(sdram)
INIT_FUNC(board_sdram_init, f, board_sdram,pre_sdram,vreg,console, )
Using board_sdram versus sdram_init is cricital:
The init sequence build tool will first create the entire init sequence
including the functions marked as sdram and board_sdram. But after
building the arrays, it will strip out all the functions marked as sdram
init functions. The reason the entire list has to be build first is so the
functions that rely on sdram can be added without unmet prerequisite
errors.
Of course, if you use SKIP_INIT(foo), you need to make sure that any
replacement INIT_FUNC will do everything foo did to make your board work.
Interestingly, this allows the following:
INIT_FUNC(calc_relocation, fr, calc_reloc, sdram, )
INIT_FUNC(copy_uboot_to_ram, fr, copy_to_ram, calc_relocation, )
INIT_FUNC(do_elf_reloc_adjusments, fr, elf_reloc, copy_to_ram, )
INIT_FUNC(clear_bss, fr, clear_bss, calc_reloc, )
#ifdef CONFIG_SYS_SKIP_RELOCATION
SKIP_INIT(calc_reloc)
SKIP_INIT(copy_to_ram)
SKIP_INIT(elf_reloc)
#endif
So if CONFIG_SYS_SKIP_RELOCATION is defined, relocation is not performed,
but clear_bss still is
I wonder what happens when you skip something - does it substitute for
any pre/post-requisites that the skipped item had? Or would that be
illegal?
I can see plenty of opportunity for confusion, but if the tool is
friendly enough, then this could solve a lot of the override problems.
In your particular example it feels like it would be easier to just
make the INIT_FUNC conditional on an config using #ifdef (horror!), or
perhaps yet another parameter(!).
Or we could just put those relocation functions in their own file and
have it omitted from the build by the Makefile in the case where
CONFIG_SYS_SKIP_RELOCATION is defined.
And if we want wanting to replace a generic function with a
board-specific one, why not just something like:
INIT_OVERRIDE(new_func, old_func)
Anyway, it sounds very promising.
Regards,
Simon
Regards,
Graeme
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Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Simon, On Fri, Jan 6, 2012 at 3:30 PM, Simon Glass s...@chromium.org wrote: Hi Graham, On Thu, Jan 5, 2012 at 2:18 PM, Graeme Russ graeme.r...@gmail.com wrote: Hi Wolfgang, On Wed, Jan 4, 2012 at 1:44 AM, Wolfgang Denk w...@denx.de wrote: Dear Graeme, In message 4f02da64.60...@gmail.com you wrote: [snip] One thing comes to mind: it would be nice if we can find a way that the INIT_FUNC definitions behave similar to weak functions - if an init_func can be redefined / overwritten / modified by board specific code we eventually have a very nice way to get rid of the related #ifdef's. I have a thought on this. How about a SKIP_INIT macro. Here's the idea using SDRAM as an example: At the arch level you may have INIT_FUNC(sdram_init, f, sdram, console,) Gosh this email took a few readings :-) Can we get rid of the 'f' parameter? If we invent a prerequisite called 'relocated' or something like that, to act as a barrier, then maybe the order can be defined just like any other function which depends on being before or after something? Well I kind of like see that a particular init function is explicitly a pre- or post- relocation function. But yes, having barrier pre-requisites would achieve the same effect. so sdram_init sets the sdram requisite and must be done after all console requisites have been completed. Now if a SoC or board has an init that must be done before SDRAM: INIT_FUNC(pre_sdram_init, f, pre_sdram, , sdram) So this sets the pre_sdram requisite, requires no other initialisation before running and must happen before and sdram init functions are run Now lets say the Soc or board has a unique sdram init function that overrides the arch's sdram init. We could just use weak functions and allow the SoC or board to override sdram_init. But what if the SoC or board has additional pre-requisite (or post-requisite) init requirements? So in the SoC or board file: SKIP_INIT(sdram) INIT_FUNC(board_sdram_init, f, board_sdram,pre_sdram,vreg,console, ) Using board_sdram versus sdram_init is cricital: The init sequence build tool will first create the entire init sequence including the functions marked as sdram and board_sdram. But after building the arrays, it will strip out all the functions marked as sdram init functions. The reason the entire list has to be build first is so the functions that rely on sdram can be added without unmet prerequisite errors. Of course, if you use SKIP_INIT(foo), you need to make sure that any replacement INIT_FUNC will do everything foo did to make your board work. Interestingly, this allows the following: INIT_FUNC(calc_relocation, fr, calc_reloc, sdram, ) INIT_FUNC(copy_uboot_to_ram, fr, copy_to_ram, calc_relocation, ) INIT_FUNC(do_elf_reloc_adjusments, fr, elf_reloc, copy_to_ram, ) INIT_FUNC(clear_bss, fr, clear_bss, calc_reloc, ) #ifdef CONFIG_SYS_SKIP_RELOCATION SKIP_INIT(calc_reloc) SKIP_INIT(copy_to_ram) SKIP_INIT(elf_reloc) #endif So if CONFIG_SYS_SKIP_RELOCATION is defined, relocation is not performed, but clear_bss still is I wonder what happens when you skip something - does it substitute for any pre/post-requisites that the skipped item had? Or would that be illegal? SKIP_INIT(foo) simply removes all 'foo' init functions from the list _after_ the list has been created - If this breaks dependencies that's your problem ;). It is up to you as the 'skipper' to make sure that you add init functions to allow things to still work I can see plenty of opportunity for confusion, but if the tool is friendly enough, then this could solve a lot of the override problems. In your particular example it feels like it would be easier to just make the INIT_FUNC conditional on an config using #ifdef (horror!), or perhaps yet another parameter(!) The idea behind this all is that we do not know today what we will need tomorrow. Our biggest issue right now is that if a board needs to tweak the init sequence, it needs to touch arch/foo/board.c and hence introduces the potential to break working boards. With this proposal, if a board wants to entirely re-write the init sequence, it can add a whole bunch of SKIP_INIT(blah) and then add it's own INIT_FUNC(init_func, myboard_bar...) and nobody else will be the wiser as to what is going on. The problem the is if the arch adds a new init step, it may not be covered by the skip list by that board - tough, lesson learn't for being so esoteric ;) Or we could just put those relocation functions in their own file and have it omitted from the build by the Makefile in the case where CONFIG_SYS_SKIP_RELOCATION is defined. Exactly. My example was a poor practical example, but it demonstrated a point. Obviously, clear_bss() does not belong with the relocation code And if we want wanting to replace a generic function with a board-specific one, why not just something like: INIT_OVERRIDE(new_func, old_func) In such circumstances, we still have weak
Re: [U-Boot] initcall revisited - A new idea to discuss
Hi, On Fri, Jan 06, 2012 at 10:29:48, Graeme Russ wrote: Hi Simon, On Fri, Jan 6, 2012 at 3:30 PM, Simon Glass s...@chromium.org wrote: Hi Graham, On Thu, Jan 5, 2012 at 2:18 PM, Graeme Russ graeme.r...@gmail.com wrote: Hi Wolfgang, On Wed, Jan 4, 2012 at 1:44 AM, Wolfgang Denk w...@denx.de wrote: Dear Graeme, In message 4f02da64.60...@gmail.com you wrote: [snip] One thing comes to mind: it would be nice if we can find a way that the INIT_FUNC definitions behave similar to weak functions - if an init_func can be redefined / overwritten / modified by board specific code we eventually have a very nice way to get rid of the related #ifdef's. I have a thought on this. How about a SKIP_INIT macro. Here's the idea using SDRAM as an example: At the arch level you may have INIT_FUNC(sdram_init, f, sdram, console,) Gosh this email took a few readings :-) Can we get rid of the 'f' parameter? If we invent a prerequisite called 'relocated' or something like that, to act as a barrier, then maybe the order can be defined just like any other function which depends on being before or after something? Well I kind of like see that a particular init function is explicitly a pre- or post- relocation function. But yes, having barrier pre-requisites would achieve the same effect. so sdram_init sets the sdram requisite and must be done after all console requisites have been completed. Now if a SoC or board has an init that must be done before SDRAM: INIT_FUNC(pre_sdram_init, f, pre_sdram, , sdram) So this sets the pre_sdram requisite, requires no other initialisation before running and must happen before and sdram init functions are run Now lets say the Soc or board has a unique sdram init function that overrides the arch's sdram init. We could just use weak functions and allow the SoC or board to override sdram_init. But what if the SoC or board has additional pre-requisite (or post-requisite) init requirements? So in the SoC or board file: SKIP_INIT(sdram) INIT_FUNC(board_sdram_init, f, board_sdram,pre_sdram,vreg,console, ) Using board_sdram versus sdram_init is cricital: The init sequence build tool will first create the entire init sequence including the functions marked as sdram and board_sdram. But after building the arrays, it will strip out all the functions marked as sdram init functions. The reason the entire list has to be build first is so the functions that rely on sdram can be added without unmet prerequisite errors. Of course, if you use SKIP_INIT(foo), you need to make sure that any replacement INIT_FUNC will do everything foo did to make your board work. Interestingly, this allows the following: INIT_FUNC(calc_relocation, fr, calc_reloc, sdram, ) INIT_FUNC(copy_uboot_to_ram, fr, copy_to_ram, calc_relocation, ) INIT_FUNC(do_elf_reloc_adjusments, fr, elf_reloc, copy_to_ram, ) INIT_FUNC(clear_bss, fr, clear_bss, calc_reloc, ) #ifdef CONFIG_SYS_SKIP_RELOCATION SKIP_INIT(calc_reloc) SKIP_INIT(copy_to_ram) SKIP_INIT(elf_reloc) #endif So if CONFIG_SYS_SKIP_RELOCATION is defined, relocation is not performed, but clear_bss still is I wonder what happens when you skip something - does it substitute for any pre/post-requisites that the skipped item had? Or would that be illegal? SKIP_INIT(foo) simply removes all 'foo' init functions from the list _after_ the list has been created - If this breaks dependencies that's your problem ;). It is up to you as the 'skipper' to make sure that you add init functions to allow things to still work Won't this lead to lots of code duplication across all boards, archs. So, tomorrow someone else will send a patch removing duplicate and merging it to a common place. Why don't start it in 1st place. I can see plenty of opportunity for confusion, but if the tool is friendly enough, then this could solve a lot of the override problems. In your particular example it feels like it would be easier to just make the INIT_FUNC conditional on an config using #ifdef (horror!), or perhaps yet another parameter(!) The idea behind this all is that we do not know today what we will need tomorrow. Our biggest issue right now is that if a board needs to tweak the init sequence, it needs to touch arch/foo/board.c and hence introduces the potential to break working boards. With this proposal, if a board wants to entirely re-write the init sequence, it can add a whole bunch of SKIP_INIT(blah) and then add it's own INIT_FUNC(init_func, myboard_bar...) and nobody else will be the wiser as to what is going on. The problem the is if the arch adds a new init step, it may not be covered by the skip list by that board - tough, lesson learn't for being so esoteric ;) So, every board, even under same arch, needs to define its own *complete-set* of INIT_CALL api's. I am dreaming about a lot of MB
Re: [U-Boot] initcall revisited - A new idea to discuss
Dear Graeme Russ, In message calbutclvdsigmpwt04+-aqpdvj_zx9zzkbxh+ifcsxdxabd...@mail.gmail.com you wrote: Can we get rid of the 'f' parameter? If we invent a prerequisite called 'relocated' or something like that, to act as a barrier, then maybe the order can be defined just like any other function which depends on being before or after something? Well I kind of like see that a particular init function is explicitly a pre- or post- relocation function. But yes, having barrier pre-requisites would achieve the same effect. I like the idea of having general synchronization (or barrier) entries, instead of pre- or post relocation, especially when considering the case of different configurations with or without SPL code or with externel pre-loaders or ... I wonder what happens when you skip something - does it substitute for any pre/post-requisites that the skipped item had? Or would that be illegal? SKIP_INIT(foo) simply removes all 'foo' init functions from the list _after_ the list has been created - If this breaks dependencies that's your problem ;). It is up to you as the 'skipper' to make sure that you add init functions to allow things to still work Isn't that always the case? The functionsprovided by the user must perform their task - the dependency checking can only test the exitence of the function that claims to provide a specific property, but it cannot check if it actually does so. With this proposal, if a board wants to entirely re-write the init sequence, it can add a whole bunch of SKIP_INIT(blah) and then add it's own INIT_FUNC(init_func, myboard_bar...) and nobody else will be the wiser as to what is going on. The problem the is if the arch adds a new init step, it may not be covered by the skip list by that board - tough, lesson learn't for being so esoteric ;) We do something similar to the implemetnation of CONFIG_CMD_ and offer a way not to include the default init list at all. Anyway, it sounds very promising. Yes, it's a lot better than my original proposal :) It's fun to see this grow. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de A fail-safe circuit will destroy others. -- Klipstein ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Dear Hebbar, Gururaja, In message 1bafe6f6c881bf42822005164f1491c305c...@dbde01.ent.ti.com you wrote: Well I kind of like see that a particular init function is explicitly a pre- or post- relocation function. But yes, having barrier pre-requisites would achieve the same effect. This point of vew is too restricted. Think of boards that use SPL, or where a rom boot loader loads U-Boot directory to RAM, or ... SKIP_INIT(foo) simply removes all 'foo' init functions from the list _after_ the list has been created - If this breaks dependencies that's your problem ;). It is up to you as the 'skipper' to make sure that you add init functions to allow things to still work Won't this lead to lots of code duplication across all boards, archs. So, tomorrow someone else will send a patch removing duplicate and merging it to a common place. I don't see why that would happen? I see no intention nor any need for duplicated code. So, every board, even under same arch, needs to define its own *complete-set* of INIT_CALL api's. I am dreaming about a lot of MB getting added to u-boot src. What makes you think so? Just a thought. Why don't split it to ARCH_INIT, BOARD_INIT,. Because it's not such an easy split. You can define such groups, like arch, SoC, board family, board. But you cannot initialize the system in such grous - instead, initialization will jump around heavily between these groups, in a sequence that needs to be well defined, and that is often diofferent from board to board. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de When properly administered, vacations do not diminish productivity: for every week you're away and get nothing done, there's another when your boss is away and you get twice as much done. -- Daniel B. Luten ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Wolfgang,
On 03/01/12 01:49, Wolfgang Denk wrote:
Dear Graeme Russ,
In message 4f019abb.9010...@gmail.com you wrote:
Which got me to thinking, what if we had an initcall macro which included
the dependency information. Imagine this rough example:
...
INITCALL(display_banner, banner, dram,board_early)
Which says that the display_banner() function, when completed fulfils the
'banner' dependency, and requires both the 'dram' and 'board_early'
dependencies to be fulfilled in order to run
Sounds great!
OK, I think I can do this...
#define INIT_FUNC(fn, stage, reqs, prereqs, postreqs) \
static const char *__initfunc_ ## fn __used \
__attribute__((__section__(.initfuncs))) = \
#stage : #fn : #reqs : #prereqs : #postreqs
'postreq' are requisite functions that the given function must be run
before (USB init priot to console if using a USB serial dongle for example)
Then:
INIT_FUNC(cpu_init_f, f, fred, blah, foo);
Generates the string:
f:cpu_init_f:fred:blah:foo
and we can parse each of the elf archives to obtain a list of string
pointers from the .initfuncs, extract the strings and process them to
generate the init arrays
and add:
/DISCARD/ : { *(.initfuncs*) }
to the linker script to throw away the strings
It's a tad ugly under the hood, but the output will be very clean
Does this sound like a plan?
Regards,
Graeme
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Re: [U-Boot] initcall revisited - A new idea to discuss
Dear Graeme,
In message 4f02da64.60...@gmail.com you wrote:
INITCALL(display_banner, banner, dram,board_early)
Which says that the display_banner() function, when completed fulfils the
'banner' dependency, and requires both the 'dram' and 'board_early'
dependencies to be fulfilled in order to run
Sounds great!
OK, I think I can do this...
#define INIT_FUNC(fn, stage, reqs, prereqs, postreqs) \
static const char *__initfunc_ ## fn __used \
__attribute__((__section__(.initfuncs))) = \
#stage : #fn : #reqs : #prereqs : #postreqs
'postreq' are requisite functions that the given function must be run
before (USB init priot to console if using a USB serial dongle for example)
Then:
INIT_FUNC(cpu_init_f, f, fred, blah, foo);
Generates the string:
f:cpu_init_f:fred:blah:foo
and we can parse each of the elf archives to obtain a list of string
pointers from the .initfuncs, extract the strings and process them to
generate the init arrays
and add:
/DISCARD/ : { *(.initfuncs*) }
to the linker script to throw away the strings
It's a tad ugly under the hood, but the output will be very clean
Does this sound like a plan?
Yes. Looks good to me.
One thing comes to mind: it would be nice if we can find a way that
the INIT_FUNC definitions behave similar to weak functions - if an
init_func can be redefined / overwritten / modified by board specific
code we eventually have a very nice way to get rid of the related
#ifdef's.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
Life sucks, but it's better than the alternative.
- Peter da Silva
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Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Graham,
On Tue, Jan 3, 2012 at 2:37 AM, Graeme Russ graeme.r...@gmail.com wrote:
Hi Wolfgang,
On 03/01/12 01:49, Wolfgang Denk wrote:
Dear Graeme Russ,
In message 4f019abb.9010...@gmail.com you wrote:
Which got me to thinking, what if we had an initcall macro which included
the dependency information. Imagine this rough example:
...
INITCALL(display_banner, banner, dram,board_early)
Which says that the display_banner() function, when completed fulfils the
'banner' dependency, and requires both the 'dram' and 'board_early'
dependencies to be fulfilled in order to run
Sounds great!
OK, I think I can do this...
#define INIT_FUNC(fn, stage, reqs, prereqs, postreqs) \
static const char *__initfunc_ ## fn __used \
__attribute__((__section__(.initfuncs))) = \
#stage : #fn : #reqs : #prereqs : #postreqs
'postreq' are requisite functions that the given function must be run
before (USB init priot to console if using a USB serial dongle for example)
Then:
INIT_FUNC(cpu_init_f, f, fred, blah, foo);
Generates the string:
f:cpu_init_f:fred:blah:foo
and we can parse each of the elf archives to obtain a list of string
pointers from the .initfuncs, extract the strings and process them to
generate the init arrays
and add:
/DISCARD/ : { *(.initfuncs*) }
to the linker script to throw away the strings
It's a tad ugly under the hood, but the output will be very clean
Does this sound like a plan?
Good with me - will be very interesting to see where this takes us.
I have been thinking if there is a way we can avoid the
post-processing perhaps by specifying two function parameters to the
macro (the init function to call and its prerequisite) and having the
initcall code sort the list before starting. We could have dummy
functions to mark particular stages of interest to boards. But it
can't deal with adding a new function as a prerequisite of an existing
one without perhaps a third parameter. I haven't looked at the
algorithm either...
But I wonder if it would be possible for your macro to generate a
table which includes the init function as well as the string? That way
we get a compile warning and link error if the function doesn't exist.
Regards,
Simon
Regards,
Graeme
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Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Wolfgang, On Wed, Jan 4, 2012 at 1:44 AM, Wolfgang Denk w...@denx.de wrote: Dear Graeme, In message 4f02da64.60...@gmail.com you wrote: [snip] One thing comes to mind: it would be nice if we can find a way that the INIT_FUNC definitions behave similar to weak functions - if an init_func can be redefined / overwritten / modified by board specific code we eventually have a very nice way to get rid of the related #ifdef's. Well a lot of the #ifdefs will disappear when the INIT_FUNC macros gets migrated the the corresponding source files as the Makefile logic will take care of things for us I do have in the back of my mind the 'what if' case of the dependencies needing to be different between two arches or boards, but I really can't think of a case where this would be the case. I added the 'post-req' to the macro to allow an init function to be inserted before an existing function which I think will be the most likely case (initialising on-board hardware such as an FPGA prior to timer initialisation for example) We'll see how it pans out Regards, Graeme ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Dear Simon Glass, In message capnjgz3aoyvypa93ecbmyqhcaazcbphfcyhxyya1ax+9_ue...@mail.gmail.com you wrote: I have been thinking if there is a way we can avoid the post-processing perhaps by specifying two function parameters to the macro (the init function to call and its prerequisite) and having the initcall code sort the list before starting. We could have dummy You mean sort at runtime? NAK. all this must be done when building, i. e. at compile time. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de The combination of a number of things to make existence worthwhile. Yes, the philosophy of 'none,' meaning 'all.' -- Spock and Lincoln, The Savage Curtain, stardate 5906.4 ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Hi Wolfgang, On Tue, Jan 3, 2012 at 2:36 PM, Wolfgang Denk w...@denx.de wrote: Dear Simon Glass, In message capnjgz3aoyvypa93ecbmyqhcaazcbphfcyhxyya1ax+9_ue...@mail.gmail.com you wrote: I have been thinking if there is a way we can avoid the post-processing perhaps by specifying two function parameters to the macro (the init function to call and its prerequisite) and having the initcall code sort the list before starting. We could have dummy You mean sort at runtime? NAK. all this must be done when building, i. e. at compile time. Yes that's what I meant. It is more flexible to do this at build time if we are happy with the additional build step. OK. Regards, Simon Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de The combination of a number of things to make existence worthwhile. Yes, the philosophy of 'none,' meaning 'all.' -- Spock and Lincoln, The Savage Curtain, stardate 5906.4 ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] initcall revisited - A new idea to discuss
Dear Graeme Russ, In message 4f019abb.9010...@gmail.com you wrote: Which got me to thinking, what if we had an initcall macro which included the dependency information. Imagine this rough example: ... INITCALL(display_banner, banner, dram,board_early) Which says that the display_banner() function, when completed fulfils the 'banner' dependency, and requires both the 'dram' and 'board_early' dependencies to be fulfilled in order to run Sounds great! Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de Our OS who art in CPU, UNIX be thy name. Thy programs run, thy syscalls done, In kernel as it is in user! ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
