I don't see an appropriate forum for this or the info so I thought I'd start out with what I (think) have discovered so far, since some of it doesn't seem to be in the documentation, I have to look of all places in gnu packages for the vectors to be defined :/ Feel free to correct me!
SH7058 uses the SH2 instruction set which is backwards compatible with all the SuperH sets above it, SH3, etc. It appears to be big endian, at least NOP's appear after all branch instructions when dissassembling this way, which you would expect.
The structure of the reset vector is as following:
0x00: PC Power on
0x04: SP Power on
0x08: PC Reset
0x12: SP Reset
In our case both are the same, makes sense!
I get a bit of unfolding so far, however IDA stops after a short while... updates later..