[U-Boot] [PATCH] config.mk: add drivers as default include PATH
Some device drivers and their header files will invoke some definitions for assembly code. If a device is required to be initilized in board.S or in lowlevel_init.S, such memory controller, flash controller, power control units. Sometimes we both need to access these devices in bootstrap process and later in normal operation period.
Hence the definitions of these drivers in the header files is required to be found in cpu and board folders. Moreover, these devices is usually built into multiple different SoC with different architectures. So the header files should be able to be shared among the SoCs.
Add this CPPFLAGS += -I$(TOPDIR)/drivers into the default include PATH will avoid such code "#include "../../../../../drivers/mtd/flash.h"
So this patch is suggested.
Signed-off-by: Macpaul Lin macpaul@andestech.com --- config.mk | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/config.mk b/config.mk index 19e0a6e..52f2280 100644 --- a/config.mk +++ b/config.mk @@ -178,6 +178,7 @@ ifneq ($(OBJTREE),$(SRCTREE)) CPPFLAGS += -I$(OBJTREE)/include2 -I$(OBJTREE)/include endif
+CPPFLAGS += -I$(TOPDIR)/drivers CPPFLAGS += -I$(TOPDIR)/include CPPFLAGS += -fno-builtin -ffreestanding -nostdinc \ -isystem $(gccincdir) -pipe $(PLATFORM_CPPFLAGS)
Dear Macpaul Lin,
In message 1292398049-3606-1-git-send-email-macpaul@andestech.com you wrote:
Some device drivers and their header files will invoke some definitions for assembly code. If a device is required to be initilized in board.S or in lowlevel_init.S, such memory controller, flash controller, power control units. Sometimes we both need to access these devices in bootstrap process and later in normal operation period.
I don't understand what you mean. Do you have a specific example where anything like this actually happens?
Hence the definitions of these drivers in the header files is required to be found in cpu and board folders. Moreover, these devices is usually built into multiple different SoC with different architectures. So the header files should be able to be shared among the SoCs.
If this happens, these header files should be at some sufficiently common location?
Add this CPPFLAGS += -I$(TOPDIR)/drivers into the default include PATH will avoid such code "#include "../../../../../drivers/mtd/flash.h"
You should always stop, lean back and start thinking where you went wrong whenever you encounter something that starts like this:
#include "../../../../../xxx
This simply does not make sense.
Best regards,
Wolfgang Denk
Dear Wolfgang,
Thanks for your patience.
2010/12/15 Wolfgang Denk wd@denx.de
Dear Macpaul Lin,
In message 1292398049-3606-1-git-send-email-macpaul@andestech.com you wrote:
Some device drivers and their header files will invoke some definitions for assembly code. If a device is required to be initilized in board.S or in lowlevel_init.S, such memory controller, flash controller, power control units. Sometimes we both need to access these devices in bootstrap process and later in normal operation period.
I don't understand what you mean. Do you have a specific example where anything like this actually happens?
Consider there are two different SoCs share the same peripheral devices. That is, two different SoC licensed the same device IP.
1. Include path problem. For example, Faraday a320 uses the same peripheral as AndesTech ag101. A320 and Ag101 will include the same header files for the same peripheral devices which are built-in into the SoC.
These SoC built-in devices include, ftsmc020.c (flash controller, arch/arm/cpu/arm920t/a320/ftsmc020.c), ftsmc020.h (flash controller, arch/arm/include/asm/arch-a320/ftsmc020.h),
ftpmu010.h (power controller, arch/arm/include/asm/arch-a320/ftpmu010.h), ftsdmc020.h (SDRAM controller, arch/arm/include/asm/arch-a320/ftsdmc020.h), fttmr010.h (RTC, arch/arm/include/asm/arch-a320/fttmr010.h).
The flash controller ftsmc020 has both assembly (offset table) and C code (structure). The other devices as assembly code only because they will be initialized in lowlevel_init.S or in board.S
1.1 At current situation, if ag101 want to include the device header file above, the code whether in "include/configs/adp-ag101.h" or in lowlevel_init.S will looks like.
#define CONFIG_FTSMC020 #ifdef CONFIG_FTSMC020 #include "../../../arch/arm/includes/asm/arch-a320/ftsmc020.h"
1.2 Even we move those header files into proper place, this problem still occur. For example, if we put ftsmc020.h and ftsmc020.c into "drivers/mtd" folder. The code in "faraday/a320evb/lowlevel_init.S" will exist #include "../../../drivers/mtd/ftsdmc020.h" and in "includes/configs/adp-ag101" will exist: #ifdef CONFIG_FTSMC020 #include "../../../drivers/mtd/ftsdmc020.h"
2. ftsmc020.c, ftsmc020.h, ftpmu010.h, ftsdmc020.h, fttmr010.h These files and headers should be put into drivers folder since there are multiple SoC share the same device controllers.
3. There is possibility we initialize device in lowlevel_init.S then reconfigure it in C level code. Such as sdram controller and flash controller. For example, in "arch/arm/include/asm/arch-at91/at91_mc.h" and in "arch/arm/include/asm/arch-a320/ftsmc020.h" There both exist assembly offset and C type structures. Once other SoC use the same device controller whether in lowlevel_int.S and in board.c, it will have include problem as described in #1 and in #2.
4. If you execute 'grep -rnH "../../Marvell/" *' in the root of u-boot code, you will find the similar situation about sharing header files with same devices. Includes, pci.h, memory.h, core.h, i2c.h. I guess even these devices is built-in in the SoC (chip), it is better to go to "drivers" folder instead of "board/Marvell/common/". Unless the policy is that we should create a specific folder for a company that sell SoC built-in devices. Like "board/Faraday/common". Otherwise it should be classified into "drivers" folder.
However, even we created a folder specific for a set of built-in devices, we still encounter the include path like: board/esd/cpci750/sdram_init.c:44:#include "../../Marvell/common/i2c.h"
5. Some shared header files of devices like "ftpmu010.h". The header file "ftpmu010.h" has only register and offset definitions. Should this kind of file go to "drivers" folder or go to "include" folder? Since they are configured like a device drivers in a SoC (in board.c or in lowlevel_init.S). I guess they should be put into "drivers" folder.
Hence the definitions of these drivers in the
header files is required to be found in cpu and board folders. Moreover, these devices is usually built into multiple different SoC with different architectures. So the header files should be able to be shared among the SoCs.
If this happens, these header files should be at some sufficiently common location?
Add this CPPFLAGS += -I$(TOPDIR)/drivers into the default include PATH will avoid such code "#include "../../../../../drivers/mtd/flash.h"
You should always stop, lean back and start thinking where you went wrong whenever you encounter something that starts like this:
#include "../../../../../xxxThis simply does not make sense.
Best regards,
Wolfgang Denk
Dear Macpaul Lin,
In message AANLkTinWnzXRV=iUqNrp_fsbN+4uKBpJLHYuXj_KOU0w@mail.gmail.com you wrote:
- Include path problem.
For example, Faraday a320 uses the same peripheral as AndesTech ag101. A320 and Ag101 will include the same header files for the same peripheral devices which are built-in into the SoC.
These SoC built-in devices include, ftsmc020.c (flash controller, arch/arm/cpu/arm920t/a320/ftsmc020.c), ftsmc020.h (flash controller, arch/arm/include/asm/arch-a320/ftsmc020.h),
ftpmu010.h (power controller, arch/arm/include/asm/arch-a320/ftpmu010.h), ftsdmc020.h (SDRAM controller, arch/arm/include/asm/arch-a320/ftsdmc020.h), fttmr010.h (RTC, arch/arm/include/asm/arch-a320/fttmr010.h).
The flash controller ftsmc020 has both assembly (offset table) and C code (structure).
The offset table should be removed. We can and should use include/generated/*-asm-offsets.h now. Just make sure the needed symbols are included.
The other devices as assembly code only because they will be initialized in lowlevel_init.S or in board.S
This is something that should be reconsidered. Why has this to be done in assembler code, and cannot - for example - be delayed until we have a C environment?
Especially the SDRAM initialization is normally done from C anyway, so why do we need it here?
1.1 At current situation, if ag101 want to include the device header file above, the code whether in "include/configs/adp-ag101.h" or in lowlevel_init.S will looks like.
#define CONFIG_FTSMC020 #ifdef CONFIG_FTSMC020 #include "../../../arch/arm/includes/asm/arch-a320/ftsmc020.h"
This is just an indication that the location of the file is not correct. If it's not a320 specific (which obliously is the case) it should be moved into a common header directory.
1.2 Even we move those header files into proper place, this problem still occur. For example, if we put ftsmc020.h and ftsmc020.c into "drivers/mtd" folder.
It seems this is not an appropriate folder. Why do you suggest this one?
- There is possibility we initialize device in lowlevel_init.S then
reconfigure it in C level code. Such as sdram controller and flash controller.
SDRAM should not be initialized in lowlevel_init.S. Please use the (new for ARM, shared with PPC which has always been using this) model where RAM initialization is done in dram_init(), i. e. as part of the init sequence in arch/arm/lib/board.c
For example, in "arch/arm/include/asm/arch-at91/at91_mc.h" and in "arch/arm/include/asm/arch-a320/ftsmc020.h" There both exist assembly offset and C type structures. Once other SoC use the same device controller whether in lowlevel_int.S and in board.c, it will have include problem as described in #1 and in #2.
See above - this means that the header file needs to be moved to acommon include directory.
- If you execute 'grep -rnH "../../Marvell/" *' in the root of u-boot
code, you will find the similar situation about sharing header files with same devices. Includes, pci.h, memory.h, core.h, i2c.h. I guess even these devices is built-in in the SoC (chip), it is better to go to "drivers" folder
drivers is not a common include directory, and thus not the right place.
instead of "board/Marvell/common/".
That may be true.
However, even we created a folder specific for a set of built-in devices, we still encounter the include path like:
Why do you make it so complicated? Just move common files to a _common_ header directory under include/ (and not drivers/).
- Some shared header files of devices like "ftpmu010.h".
The header file "ftpmu010.h" has only register and offset definitions. Should this kind of file go to "drivers" folder or go to "include" folder?
1) offset definitions should be removed; instead, *-asm-offsets.h should be used.
2) drivers/ is not a location for common header files that are referenced by non-driver code. Use include/ for such common code, assuming it is really common to all architectures. Use arch/arm/include/ if it's common to ARM systems only.
Since they are configured like a device drivers in a SoC (in board.c or in lowlevel_init.S). I guess they should be put into "drivers" folder.
If this is common driver code, the code itself should be moved to drivers (and then, and only then, the header files with the code).
Best regards,
Wolfgang Denk
Dear Wolfgang,
2010/12/16 Wolfgang Denk wd@denx.de:
Dear Macpaul Lin,
- There is possibility we initialize device in lowlevel_init.S then
reconfigure it in C level code. Such as sdram controller and flash controller.
SDRAM should not be initialized in lowlevel_init.S. Please use the (new for ARM, shared with PPC which has always been using this) model where RAM initialization is done in dram_init(), i. e. as part of the init sequence in arch/arm/lib/board.c
For example, in "arch/arm/include/asm/arch-at91/at91_mc.h" and in "arch/arm/include/asm/arch-a320/ftsmc020.h" There both exist assembly offset and C type structures. Once other SoC use the same device controller whether in lowlevel_int.S and in board.c, it will have include problem as described in #1 and in #2.
See above - this means that the header file needs to be moved to acommon include directory.
- If you execute 'grep -rnH "../../Marvell/" *' in the root of u-boot
code, you will find the similar situation about sharing header files with same devices. Includes, pci.h, memory.h, core.h, i2c.h. I guess even these devices is built-in in the SoC (chip), it is better to go to "drivers" folder
drivers is not a common include directory, and thus not the right place.
instead of "board/Marvell/common/".
That may be true.
Since they are configured like a device drivers in a SoC (in board.c or in lowlevel_init.S). I guess they should be put into "drivers" folder.
If this is common driver code, the code itself should be moved to drivers (and then, and only then, the header files with the code).
Best regards,
Wolfgang Denk
Your opinion is understood.
1. I will trying to make those shared devices being configurable as C drivers instead of assembly definitions as possible. 2. For those devices which is hard/unnecessary to write a driver, I will take effort on creating a common folder something like include/faraday or include/faraday/common to collect those definitions.
Le 16/12/2010 13:18, Wolfgang Denk a écrit :
SDRAM should not be initialized in lowlevel_init.S. Please use the (new for ARM, shared with PPC which has always been using this) model where RAM initialization is done in dram_init(), i. e. as part of the init sequence in arch/arm/lib/board.c
Just a note: some ARM SoCs may not have IRAM easily available (Marvell 5182 for instance; it may not even be able to use its data cache for IRAM). In this case, even setting up a partial C environment for board_init_f may require initializing SDRAM in lowlevel_init.S.
Amicalement,
participants (4)
-
Albert ARIBAUD -
Macpaul Lin -
Macpaul Lin -
Wolfgang Denk