Hi:
It is true that a filesystem that has a usermode component can not be used as a boot driver
I beleive this is not true. There are operating systems (at least I could name one) with all the drivers running in user mode leaving only a minimal kernel. Is sort of a client-server model, and yes with protection for file/folders. Now the ROS boot loader first loads kernel-hal-fat driver-... It has to, otherwise how would you load the filesystem driver? Now switching ring 0 <-> ring 3 with that in RAM... If you also load ntdll that way. Hmmm Why not? I beleive that is enought to read/write something to disk.
Regards Waldo
Waldo Alvarez Cañizares wrote:
Hi:
It is true that a filesystem that has a usermode component can not be used as a boot driver
I beleive this is not true. There are operating systems (at least I could name one) with all the drivers running in user mode leaving only a minimal kernel. Is sort of a client-server model, and yes with protection for file/folders. Now the ROS boot loader first loads kernel-hal-fat driver-... It has to, otherwise how would you load the filesystem driver? Now switching ring 0 <-> ring 3 with that in RAM... If you also load ntdll that way. Hmmm Why not? I beleive that is enought to read/write something to disk.
Hmmm... maybe I misspoke and wasn't clear.
What I meant to say was that a filesystem that requires a user-mode component can not be the boot filesystem.
Thanks,
Joseph
What I meant to say was that a filesystem that requires a user-mode component can not be the boot filesystem.
I agree with you. The problem with the filesystem proposed in the recent mail is that it depends on a _secondary_ and tertiary usermode component - which itself requires the FS to be loaded already. Maybe it would be possible to have a monolithic usermode (DB) FS-driver booting the system if the loader boots like -> kernel + hal + usermode-FS.
However, the "DB filesystem" described so far would require: -> kernel + hal + Usermode[MySQL + Tcl + ... + FS].
How can you load MySQL and Tcl without the (whatever-mode) FS?
Consequence: it's not bootable! (okay, maybe coLinux could run there ;-)
Just my two cents,
Oliver
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Joseph Galbraith -
Oliver Schneider -
Waldo Alvarez Cañizares