Dear Michele,
In message BA4D40DBFB024E51BCB0052BCFB5199E@ebneuro.intranet you wrote:
I am using UBoot on a AT91RM9200 target supporting Linux 2.4.27. I would like to accelerate the boot process, while keeping Kernel and RamDisk compressed on Flash EPROM.
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Instead of copying the compressed RamDisk Flash code to SDRAM, and then
Rather than doing this, I would teach the kernel to deal with a ramdisk image in flash. This has been done before. Patches (and references to the patches) have been postewd on this list multiple times.
to decompress the RamDisk, can U Boot uncompress the RamDisk on behalf of the Kernel, then presenting
U-Boot can do nothing "on behalf of the Kernel", because U-Boot doesn't exist any more once the kernel booted.
But of course U-Boot can load and uncompress the ramdisk image and pass the address of the uncompressed image to the kernel. See the FAQ.
The idea is to skip the step of simply copying a compressed image from Flash to SDRAM, but directly uncompressing the Flash image to SDRAM.
This is easier to solve by teaching your Linux kernel to be a bit more clever.
Sure this can be accomplished patching U Boot ad hoc, but can it be done through standard commands and variables ?
Yes, see above.
Also keep in mind that turning of the checksums (verify=no) helps a bit.
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: wd@denx.de Nothing ever becomes real until it is experienced. - John Keats