The first packet the one sec mode should send is a mode 1 real time packet, same as GET_REAL_TIME.
A mode 2 packet is the same but doesn't include the time.
They are incomplete or unused (includes cmd and count but not the data and the count isn't used). Might as well get everything from the class fields in_buf and in_count.
GET_REAL_TIME was using the wrong offset and wasn't setting out_count.
May need to add time zone offset which could be different between host and guest.
get-time and set-time can be tested in Open Firmware.
SET_REAL_TIME is used by the Date/Time Control Panel when you change the date.
It is unknown what method Mac OS uses to get the time at boot. Mac OS 8.6 does not use GET_REAL_TIME during boot, so the time is left as 12:00 AM Jan 1, 1904.
None of the POWER opcodes uses it now, plus it is a duplicate of ppc_setsoov (though ppc_setsoov is inline so it would have to be moved to be able to use it in poweropcodes.cpp?
Use U instead of UL. U will use the smallest size that can fit all the unsigned bytes. Since 0xFFFFFFFF fits in 32 bits, the 0xFFFFFFFFU is a uint32_t.
Including bits of rot_sh in the rA and MQ calculations is nonsensical since it is a rotation count and not a source of bits to be extracted or rotated.
The mask is not complicated, so we don't need to use power_rot_mask.
Fix carry flag calculation. Anding with the rotation count (n = rB) is nonsensical.
(r & ~mask) is the rotated word ANDed with the complement of the generated mask of n zeros followed by 32 - n ones.
The manual says this 32-bit result is ORed together. This means all the bits are ORed together which is equivalent to saying 0 if all zeros and 1 if any ones. In other words: (r & ~mask) != 0.
This boolean is ANDed with bit 0 of rS to produce the carry. int32_t(rS) < 0 will test bit 0. The && operator will treat each side as a boolean so you can exclude "!= 0" tests.
If bit 26 of rB is set then the mask should be all ones.
If bit 26 of rB is set then rA should be all ones or all zeros (depending on the sign bit of rA).
