Re: [PATCH] allow use of mtd and jffs2 on uml

[Sam Ravnborg <sam@ravnborg.org>]

On Thu, Dec 27, 2007 at 01:15:25PM -0500, Jason Lunz wrote:
> 
> Allow parts of drivers/mtd to compile on uml by pushing the HAS_IOMEM
> dependencies down closer to the parts of mtd that actually need it. This
> allows enough of mtd to build to let jffs2 be used on uml.
> 
> Signed-off-by: Jason Lunz <lunz@falooley.org>
> 
> ---
> 
>  arch/um/Kconfig             |    4 +---
>  drivers/mtd/Kconfig         |   12 +++++++-----
>  drivers/mtd/chips/Kconfig   |   11 ++++++++---
>  drivers/mtd/devices/Kconfig |    7 +++++++
>  4 files changed, 23 insertions(+), 11 deletions(-)
> 
> Index: linux-2.6.23.1-uml/arch/um/Kconfig
> ===================================================================
> --- linux-2.6.23.1-uml.orig/arch/um/Kconfig
> +++ linux-2.6.23.1-uml/arch/um/Kconfig
> @@ -326,9 +326,7 @@
>  
>  source "drivers/md/Kconfig"
>  
> -if BROKEN
> -	source "drivers/mtd/Kconfig"
> -endif
> +source "drivers/mtd/Kconfig"
>  
>  #This is just to shut up some Kconfig warnings, so no prompt.
>  config INPUT
> Index: linux-2.6.23.1-uml/drivers/mtd/devices/Kconfig
> ===================================================================
> --- linux-2.6.23.1-uml.orig/drivers/mtd/devices/Kconfig
> +++ linux-2.6.23.1-uml/drivers/mtd/devices/Kconfig
> @@ -78,6 +78,7 @@
>  
>  config MTD_SLRAM
>  	tristate "Uncached system RAM"
> + 	depends on HAS_IOMEM
>  	help
>  	  If your CPU cannot cache all of the physical memory in your machine,
>  	  you can still use it for storage or swap by using this driver to
> @@ -85,6 +86,7 @@
>  
>  config MTD_PHRAM
>  	tristate "Physical system RAM"
> + 	depends on HAS_IOMEM
>  	help
>  	  This is a re-implementation of the slram driver above.
>  
> @@ -151,10 +153,13 @@
>  	  Testing MTD users (eg JFFS2) on large media and media that might
>  	  be removed during a write (using the floppy drive).
>  
> +if HAS_IOMEM
>  comment "Disk-On-Chip Device Drivers"
> +endif

You can expand the if above to include the config symols..
>  
>  config MTD_DOC2000
>  	tristate "M-Systems Disk-On-Chip 2000 and Millennium (DEPRECATED)"
> + 	depends on HAS_IOMEM
>  	select MTD_DOCPROBE
>  	select MTD_NAND_IDS
>  	---help---
> @@ -177,6 +182,7 @@
>  
>  config MTD_DOC2001
>  	tristate "M-Systems Disk-On-Chip Millennium-only alternative driver (DEPRECATED)"
> + 	depends on HAS_IOMEM
>  	select MTD_DOCPROBE
>  	select MTD_NAND_IDS
>  	---help---
> @@ -198,6 +204,7 @@
>  
>  config MTD_DOC2001PLUS
>  	tristate "M-Systems Disk-On-Chip Millennium Plus"
> + 	depends on HAS_IOMEM
>  	select MTD_DOCPROBE
>  	select MTD_NAND_IDS
>  	---help---
.. so if the endif was placed here you did not have to specify
the "depends on". Assumng btw that no other symbols inbetween
exists.

> Index: linux-2.6.23.1-uml/drivers/mtd/Kconfig
> ===================================================================
> --- linux-2.6.23.1-uml.orig/drivers/mtd/Kconfig
> +++ linux-2.6.23.1-uml/drivers/mtd/Kconfig
> @@ -2,7 +2,6 @@
>  
>  menuconfig MTD
>  	tristate "Memory Technology Device (MTD) support"
> -	depends on HAS_IOMEM
>  	help
>  	  Memory Technology Devices are flash, RAM and similar chips, often
>  	  used for solid state file systems on embedded devices. This option
> @@ -278,15 +277,18 @@
>  	  This enables read only access to SmartMedia formatted NAND
>  	  flash. You can mount it with FAT file system.
>  
> -source "drivers/mtd/chips/Kconfig"
>  
> -source "drivers/mtd/maps/Kconfig"
> +if HAS_IOMEM
> +	source "drivers/mtd/chips/Kconfig"
> +	source "drivers/mtd/maps/Kconfig"
> +endif

This "if" should be pushed down in the kconfig file
so it is obvoious we have this dependency.
>  
>  source "drivers/mtd/devices/Kconfig"
>  
> -source "drivers/mtd/nand/Kconfig"
> -
> -source "drivers/mtd/onenand/Kconfig"
> +if HAS_IOMEM
> +	source "drivers/mtd/nand/Kconfig"
> +	source "drivers/mtd/onenand/Kconfig"
> +endif
Same for this one - let it be explicit in the Kconfig file.

>  
>  source "drivers/mtd/ubi/Kconfig"
>  
> Index: linux-2.6.23.1-uml/drivers/mtd/Makefile
> ===================================================================
> --- linux-2.6.23.1-uml.orig/drivers/mtd/Makefile
> +++ linux-2.6.23.1-uml/drivers/mtd/Makefile
> @@ -26,6 +26,9 @@
>  nftl-objs		:= nftlcore.o nftlmount.o
>  inftl-objs		:= inftlcore.o inftlmount.o
>  
> -obj-y		+= chips/ maps/ devices/ nand/ onenand/
> +obj-y		+= devices/
> +ifdef CONFIG_HAS_IOMEM
> +obj-y		+= chips/ maps/ nand/ onenand/
> +endif

The ifdef for CONFIG_HAS_IOMEM looks strange.
Let kbuild visit the directories and then figure out nothing
needs to be done.
If you insist on the HAS_IOMEM dependency then use:
obj-$(CONFIG_HAS_IOMEM) += chips/ maps/ nand/ o


	Sam