Hi Steve,  I'm the one that made this edit.

I agree that the call to "toMemorySize()" on an address seems strange, but it's an idiom that seems pretty well spread throughout gem5. Saying that something lives at "512MB" for an address is used in multiple places.


1. It's pretty well baked into the AddrRange() param as most places that call it give it a starting address or size in MB, GB, etc which is then directly passed to Addr() within the param class.

common/FSConfig.py
143:    self.mem_ranges = [AddrRange(Addr('1MB'), size = '64MB'),
144:                       AddrRange(Addr('2GB'), size ='256MB')]
405:        self.mem_ranges = [AddrRange('3GB'),
406:            AddrRange(Addr('4GB'), size = excess_mem_size)]


2. It's also used on other systems for arithmetic.

src/arch/sparc/SparcSystem.py
59:    hypervisor_addr = Param.Addr(Addr('64kB') + _rom_base,
61:    openboot_addr = Param.Addr(Addr('512kB') + _rom_base,




It could be changed over, but this would require changing multiple other places in the code.  Changing these places, which are really trying to directly set an "Addr" to "MemorySize", also seems wrong though.  In the FSConfig.py example, we're trying to specify the starting address, not a MemorySize.

Either way is going to have some bad semantics (unless we get rid of the ability to nicely specify starting addresses via "sizes").

Any additional comments?

Thanks for the response, Mitch.

The patch itself makes sense; we certainly do want people to be able to use hex constants for addresses. It's really the status quo that I am annoyed with :). I agree that it's a reasonable idiom to use a size to indicate an address. It would still be nice if we actually used MemorySize when we wanted a size though.

My one request would be, now that we've worked through this, to add a brief comment above the existing toMemorySize() call (or maybe above the whole try/except clause) to add some of this perspective to the code itself.

Ok now?