Re: z/Architecture?


Joe Monk
 

"I have recently taken interest in going further to develop UDOS into a 
more wide scope. This is by allowing UDOS to act as a hypervisor for 
let's say running z/OS under a VM and z/Linux too."

The SIE instruction is IBM patented and licensed technology. Good luck with finding information on its operation and details.

"Another question: Modifying IBM millicode

Achievable or outright impossible? I've heard it's not possible but i 
may be wrong."

Not possible without physical access to the Hardware Support Element (a pair of 1U servers that are physically located inside the machine).

"How to drive the timer?

I'm trying to activate the timer, I'm using the SET TIMER and STORE 
timer instructions and set it to a positive value that should generate 
an external interrupt once it goes to the negative. But no external 
interruption is recognized - what am i doing wrong?"

Do you have interrupts enabled for the CPU timer? Bit 53 of control register 0 must be 1.

Joe

On Sat, Oct 23, 2021 at 12:37 PM Jesus Antonio <jesusantonio30122016@...> wrote:
Hi.


As I'm writing this I'm compiling the latest version of clang in hopes
of circumventing the z/Architecture negative indexes code generation
"bug" present on the GCC compiler. I also want to avoid the EBCDIC
formatting problems present on GCC. Hopefully i can use EBCDIC normally
without any barriers (such as spurious warnings).


Now for the main question: z/Architecture Hypervisor and Virtualization
Technologies

I have recently taken interest in going further to develop UDOS into a
more wide scope. This is by allowing UDOS to act as a hypervisor for
let's say running z/OS under a VM and z/Linux too.

How can i accomplish this task, what hypervisor functionality i need? Is
this even achievable?


Another question: Modifying IBM millicode

Achievable or outright impossible? I've heard it's not possible but i
may be wrong.


How to drive the timer?

I'm trying to activate the timer, I'm using the SET TIMER and STORE
timer instructions and set it to a positive value that should generate
an external interrupt once it goes to the negative. But no external
interruption is recognized - what am i doing wrong?


Adios.

- jesus






Join hercules-380@groups.io to automatically receive all group messages.