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Szwg Spec Cramfs

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Contents

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Introduction

  • This method is useful for FS ROM size reduction.
  • Cramfs, which is read-only FS, shrinks ROM size of programs while it takes longer loading time of them from ROM into RAM.
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Rationale

  • Cramfs is compressed file system and it makes FS's ROM size smaller. The file system can be used as Read Only.
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Specifications

  • Kernel SHOULD support file systems with compression feature (CONFIG_CRAMFS)
  • Kernel SHOULD support block device access feature (CONFIG_MTD_BLOCK)
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Notes(informational and non-normative)

Pros and Cons:

  • There is almost no impact on Kernel ROM size and RAM size.
  • The FS ROM size can be reduced by 40%-55%(or 1.1Mbyte-2Mbyte). 
Actual data is shown in Appendix  ( Appendix A_R2)
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References

  • This feature is implemented in CELF 1.0 as well as master Linux (2.4 kernel at least)
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Remaining Issues

  • Some data on the platform are still missing.
Retrieved from "http://www.elinux.org/Szwg_Spec_Cramfs"
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