2008-03-07 15:10:54 disabling rootfs to free memory
David Rowe (AUSTRALIA)
Message: 52203 Hi,
On the IP04 hardware I am using I would like to remove (or at least greatly reduce) the memory used by rootfs. My root filesystem is on yaffs so a ram based rootfs file system is not required. I am using uClinux-dist-2007R1.1-RC3.
Could some one pls suggest the correct CONFIG options to select?
Here is my current dmesg:
Kernel Managed Memory: 64MB
Memory map:
text = 0x00001000-0x00158284
init = 0x00159000-0x00169948
data = 0x0016ba50-0x001abe90
stack = 0x0016c000-0x0016e000
bss = 0x001abe90-0x001ba004
available = 0x001ba004-0x03700000
rootfs = 0x03700000-0x03f00000
DMA Zone = 0x03f00000-0x04000000
<snip>
VFS: Mounted root (yaffs filesystem).
root:~>
I would like to see as above with the rootfs entry removed. I tried turning off:
Drivers-Memory Technology Devices (MTD) Mapping drivers for chip access - Generic uClinux RAM/ROM filesystem support
This gets me close:
Kernel Managed Memory: 64MB
Memory map:
text = 0x00001000-0x00157cd0
init = 0x00158000-0x0046b1ac
data = 0x0046d260-0x004addc0
stack = 0x0046e000-0x00470000
bss = 0x004addc0-0x004bbf20
available = 0x004bbf20-0x03eff000
DMA Zone = 0x03f00000-0x04000000
truction Cache Enabled
Data Cache Enabled (write-back)
Hardware Trace Enabled
Built 1 zonelists. Total pages: 16002
Kernel command line: ethaddr=00:09:45:53:d1:ee console=ttyBF0,115200 root=/dev/mtdblock2 rw
<snip>
root:~> free
total used free shared buffers
Mem: 62232 8300 53932 0 0
root:~> mount
rootfs on / type rootfs (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
usbfs on /proc/bus/usb type usbfs (rw)
securityfs on /sys/kernel/security type securityfs (rw)
Lots of memory (great!), however for some reason (despite the kernel command line), root is not mounted on yaffs (mtdblock2). Also - despite removing rootfs for the kernel I seem to have a ram based rootsfs from somewhere.
Any suggestions would be much appreciated.
Thanks,
David
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2008-03-07 15:27:50 Re: disabling rootfs to free memory
Mike Frysinger (UNITED STATES)
Message: 52204 the uClinux MTD RAM option controls the ramdisk backed rootfs (which is the "rootfs" in the memory map)
the initramfs option controls the ramfs backed rootfs
however, these options are only checked by the ADI Makefile's in the uclinux-dist ... if you're creating your own, you can modify the images target to produce the images you want