The previous texture_memory_alloc.hpp was written based on an
incorrect understanding of the "32-bit" and "64-bit" texture memory
address mapping.
The primary motivation is to rearrange the texture memory address map
so that "textures" (64-bit access) do not overlap with 32-bit
accesses, such as REGION_BASE or PARAM_BASE.
The serial_transfer loader, as long as the target program voluntarily
terminates itself at some point, is able to load multiple programs
consecutively without requiring a physical power cycle to reload the
transfer program from CD.
The current example.mk juggles between two different "memory layouts",
one for "burn to a physical CD" and another for "load via serial
cable". Because the serial_transfer program now relocates itself to
the end of system memory, this means the 0x8c010000 area is now usable
by programs that are loaded by serial_transfer.
From the GCC manual.
> GCC permits a C structure to have no members:
struct empty {
};
> The structure has size zero. In C++, empty structures are part of the
> language. G++ treats empty structures as if they had a single member of type
> char.
I was not aware of the different behavior in C++.
This fixes every maple example--most were broken for multiple reasons, including
this one.
This also enables SH4 caching. This includes linking code/data into the P1
area (previously this was not the case).
The maple examples (which indeed involve much use of DMA) require much work to
successfully work with the operand and copyback caches. The vibration example
currently is the most complete, though I should consider more on how I want to
structure maple response operand cache invalidation more generally.
This also adds ta_parameter_writer; I am not certain if I like this,
but it felt necessary to deal with ta_parameters being either 32 or 64
bytes long--for this reason, a reinterpret_cast to a union is less
attractive (the union members are not a fixed size).
