Allow VRAM presence only in optional bank.
control: Implement banks.
The BAR is 64MB.
The little-endian/big-endian ranges repeat every 16MB.
An endian range can be addressed in d128 (wide) mode or d64 mode.
In d128 mode, there is a 4MB range followed by an undefined 4MB range. bytes 0..7 belong to the standard bank and bytes 8..15 belong to the optional bank.
In d64 mode:
- 2MB mirror ranges at 0MB and 2MB (both have the same read/write behavor: write to both banks or read from the standard bank.
- 2MB standard bank rage at 4MB.
- 2MB optional bank range at 6MB.
- Add IOBusDevice (nvram_addr_hi_dev) for NVRAM addr hi.
- Add IOBusDevice (nvram_dev) for NVRAM data.
- Make all IOBusDevices use the same code.
- Log error if 4 least significant bits of offset are not zero.
- Correctly byte swap the value before passing it to the IOBusDevice.
- When reading, duplicate the bytes in a word or dword like a real Power Mac does.
- Fix video vram endianness. It should behave like RAM.
- Add read for registers ENABLE, INT_STATUS, INT_ENABLE.
- Add write for registers CNTTST, INT_ENABLE.
- Add support for 16bpp and 32bpp.
- Add vbl interrupt.
While dingusppc only emulates 32-bit Macs (for now), it is possible for a 32-bit Power Mac to use a PCIe card that has 64-bit BARs.
finish_config_bars is added to scan the cfg values of the BARs and determine their type. The type is stored separately so that it does not need to be determined again.
The type can be I/O (16 or 32 bit) or Mem (20 or 32 or 64 bit). A 64 bit bar is two BARs, the second contains the most significant 32 bits.
set_bar_value uses the stored type instead of trying to determine the type itself. It is always called even when the firmware is doing sizing. For sizing, It does the job of setting the bar value so do_bar_sizing is now just a stub.
Every PCIDevice that has a BAR needs to call finish_config_bars after setting up the cfg values just as they need to setup the cfg values. Since they need to do both, maybe the cfg values should be arguments of finish_config_bars, then finish_config_bars() should be renamed config_bars().
BAR 0 exists on a real Power Mac 8600 and the dingusppc 7500.
On a Power Mac 8600, the initial value is 0x84000003. In Open Firmware, you can write to all bits of the BAR and read the value back except the 2 least significant bits are always %11. Bit 0 indicates I/O space. Bit 1 is reserved and should be zero so maybe this is not a real I/O space BAR. 0x8400000 is written to the BAR by Open Firmware. It doesn't look like a normal I/O address which are usually 16 bits.
On the emulated 7500, 0x02000000 is written to the BAR by Open Firmware sometime during probe-all. The BAR did not behave as it does in the Power Mac 8600. This commit fixes that.
Two questions remain:
1) Which fcode writes to the BAR? Is it the probe fcode or is it the control fcode? There's no config-_! in the control fcode.
2) What is the purpose of the BAR? Writing to it can cause a hang. The testbits code below seems to succeed - it restores the original value after reading the result of testing each bit and before displaying the result. The values shown for the MSB (0x84 on the 8600 and 0x02 on the 7500) could be three flag bits.
```
dev vci0
: testbits { adr ; org }
cr
adr config-l@ dup -> org ." original : " 8 u.r cr
20 0 do
1 1f i - << dup 8 u.r ." : "
adr config-l!
adr config-l@
org adr config-l!
8 u.r cr
loop
;
15810 testbits \ 15810 is the address of the BAR on the emulated 7500.
```
BAR 0 exists on a real Power Mac 8600 and the dingusppc 7500.
On a Power Mac 8600, the initial value is 0x84000003. In Open Firmware, you can write to all bits of the BAR and read the value back except the 2 least significant bits are always %11. Bit 0 indicates I/O space. Bit 1 is reserved and should be zero so maybe this is not a real I/O space BAR. 0x8400000 is written to the BAR by Open Firmware. It doesn't look like a normal I/O address which are usually 16 bits.
On the emulated 7500, 0x02000000 is written to the BAR by Open Firmware sometime during probe-all. The BAR did not behave as it does in the Power Mac 8600. This commit fixes that.
Two questions remain:
1) Which fcode writes to the BAR? Is it the probe fcode or is it the control fcode? There's no config-_! in the control fcode.
2) What is the purpose of the BAR? Writing to it can cause a hang. The testbits code below seems to succeed - it restores the original value after reading the result of testing each bit and before displaying the result. The values shown for the MSB (0x84 on the 8600 and 0x02 on the 7500) could be three flag bits.
```
dev vci0
: testbits { adr ; org }
cr
adr config-l@ dup -> org ." original : " 8 u.r cr
20 0 do
1 1f i - << dup 8 u.r ." : "
adr config-l!
adr config-l@
org adr config-l!
8 u.r cr
loop
;
15810 testbits \ 15810 is the address of the BAR on the emulated 7500.
```
