Re: [PATCH 2/5] mips: PMC MSP71xx mips common

[Marc St-Jean <Marc_St-Jean@pmc-sierra.com>]

David Daney wrote:
> Marc St-Jean wrote:
>  >
>  > Sergei Shtylyov wrote:
>  >> Hello.
>  >>
>  >> Marc St-Jean wrote:
>  >>
>  >>  > [PATCH 2/5] mips: PMC MSP71xx mips common
>  >>
>  >>  > Patch to add mips common support for the PMC-Sierra
>  >>  > MSP71xx devices.
>  >>
>  >>  > These 5 patches along with the previously posted serial patch
>  >>  > will boot the PMC-Sierra MSP7120 Residential Gateway board.
>  >>
>  >>  > Signed-off-by: Marc St-Jean <Marc_St-Jean@pmc-sierra.com>
>  >>
>  >>  > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
>  >>  > index 5da6b0d..d512389 100644
>  >>  > --- a/arch/mips/Kconfig
>  >>  > +++ b/arch/mips/Kconfig
>  >> [...]
>  >>
>  >>  > +menu "Options for PMC-Sierra MSP chipsets"
>  >>  > +     depends on PMC_MSP
>  >>  > +
>  >>  > +config PMC_MSP_EMBEDDED_ROOTFS
>  >>  > +     bool "Root filesystem embedded in kernel image"
>  >>  > +     select MTD
>  >>  > +     select MTD_BLOCK
>  >>  > +     select MTD_PMC_MSP_RAMROOT
>  >>  > +     select MTD_RAM
>  >>  > +
>  >>
>  >>     Hm, why not just use initramfs?
>  >
>  > I investigated this as part of an earlier thread.  Initramfs
>  > is not a read-only "ROM" fs but a compressed writable fs.
>  > Once expanded it will take more memory.
>  >
>  > To lower memory usage for embedded usage of our devices we've
>  > added a method to embedded cramfs/squashfs file systems into
>  > the kernel image.
>  >
> 
> Why not just run the cramfs/squashfs on a standard mdtblock device?

We and our customers do that as well but it's handy to have a single
RAM-based image to download during early development.

MArc

> 
>  > I've made sure it was unobtrusive and that no linker script
>  > changes, etc. were required.
>  >
>  >
>