Pardon the delay: Honesty is the best policy... but not my only policy!
OK we are concerned with 4 "programs" when upgrading to WinCE.Net4.2... 3 of which reside in the MP900 ROM:
1. Bios 2. Bootloader 3. Kernel/OS 4. The Flashing program
I will use the analogy of the MP900/c as the same as a House with many rooms.
When you first turn on your HPC
(or any computer
) the first "program" to run is the Bios
(or EFI in newer devices
). It has the job of providing the "blueprints" of the House: the total number of rooms, the type and location of rooms like Kitchen, bathrooms, bedrooms, garage, pantry, living room, etc. Instead of rooms, the Bios looks for and records "devices" such as RAM memory
(a locker room with many numbered lockers for storing things
), video display, keyboard, touch screen or mouse, network card/ wifi, storage card, which hard drive
( the ROM in the MP900 case
) contains the master boot record and the critically important location of bootloader files and kernel/OS files. etc.
If you shop in a Big Box store like Best Buy or Costco after you pay the cashier and go to leave the store you run into a Bouncer-type person
(Bios
) who demands to see your receipt and everything in your cart and then checks off each item before letting you advance/ leave. If everything checks out accurately, the Bios then allows the computer to advance to the Bootloader stage by handing the list of devices, their locations and types over to it along with info on the size of RAM, ROM, Storage, video/audio/touchscreen parameter.
So, the Bios creates a blueprint of the computer and then starts/calls up the bootloader , hands it the blueprints along with additional data, then leaves the scene as the Bootloader takes over.
Now, The Bootloader is similar to the Home Moving Truck Operator and the ROM / boot drive is the Truck Load of contents/ furnishings, etc. The Bootloader starts delivering up chunks of the Kernel/OS/packages/files and moves them into various rooms/cabinets/lockers, etc. When done, it starts/calls up the Kernel
( which is similar to a Butler/Bouncer/Security Guard type of fellow
), shows it the checklist of what's been delivered, with location and state
(coffee pot is on and brewing, AC is off, water and electricity are connected
).
Obviously, we assume every entity here is speaking and understanding the same lanquage. You can imagine what happens when the bootloader has difficulty understanding the proper "computer-ese" The wrong bootloader puts the potting soil and insectcide in the refrigerator, the sofa in the swimming pool, the ice cream in the bed, and way, way too much toilet paper in the commode! The kernel given the wrong info locks all the I/O doors and windows so nothing gets processed,or dumps its results down the toilet
(because the bios told the bootloader the toilet is a window
).
(Toilet water means different things if you make perfume vs if you are a plumber
). Or the Kernal loads the wrong driver for the wrong device, etc...
(Not so "finger licking good"as the good Colonel might say
).
more to follow,
joval posted from a J720/Devuan3.16/RasPi/Firefox Hybrid
Edited by joval 2021-07-18 6:32 PM