190718fbee
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.
```
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| .github | ||
| benchmark | ||
| core | ||
| cpu/ppc | ||
| debugger | ||
| devices | ||
| machines | ||
| thirdparty | ||
| utils | ||
| zdocs | ||
| _config.yml | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| CMakeLists.txt | ||
| CMakeSettings.json | ||
| CONTRIBUTING.md | ||
| dppcicon.ico | ||
| endianswap.h | ||
| icon.rc | ||
| LICENSE | ||
| main.cpp | ||
| memaccess.h | ||
| README.md | ||
| vcpkg.json | ||
DingusPPC
Written by divingkatae and maximumspatium
Be warned the program is highly unfinished and could use a lot of testing. Any feedback is welcome.
Philosophy of Use
While many other PowerPC emus exist (PearPC, Sheepshaver), none of them currently attempt emulation of PPC Macs accurately (except for QEMU).
This program aims to not only improve upon what Sheepshaver, PearPC, and other PowerPC mac emulators have done, but also to provide a better debugging environment. This currently is designed to work best with PowerPC Old World ROMs, including those of the PowerMac G3 Beige.
Implemented Features
This emulator has a debugging environment, complete with a disassembler. We also have implemented enough to allow Open Firmware to boot, going so far as to allow audio playback of the boot-up jingles.
How to Use
This program currently uses the command prompt to work.
There are a few command line arguments one must enter when starting the program.
-r, --realtime
Run the emulator in runtime.
-d, --debugger
Enter the interactive debugger.
-b, --bootrom TEXT:FILE
Specifies the Boot ROM path (optional; looks for bootrom.bin by default)
-m, --machine TEXT
Specify machine ID (optional; will attempt to determine machine ID from the boot rom otherwise)
As of now, only the Power Macintosh G3 Beige is implemented.
How to Compile
You need to install development tools first.
At least, a C++11 compliant compiler and CMake are required.
You will also have to recursive clone or run
git submodule update --init --recursive
This is because the CubeB module is not included by default. All other components are already included in the thirdparty folder and compiled along with the rest of DingusPPC.
For example, to build the project in a Unix-like environment, you will need to run the following commands in the OS terminal:
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make dingusppc
You may specify another build type using the variable CMAKE_BUILD_TYPE.
Future versions may drop SDL 2 as a requirement.
For Raspbian, you may also need the following command:
sudo apt install doxygen graphviz
Testing
DingusPPC includes a test suite for verifying the correctness of its PowerPC CPU emulation. To build the tests, use the following terminal commands:
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make testppc
Intended Minimum Requirements
- Windows 7 or newer (64-bit), Linux 4.4 or newer, Mac OS X 10.9 or newer (64-bit)
- Intel Core 2 Duo or better
- 2 GB of RAM
- 2 GB of Hard Disk Space
- Graphics Card with a minimum resolution of 800*600
Compiler Requirements
- GCC 4.7 or newer (i.e. CodeBlocks 13.12 or newer)
- Visual Studio 2013 or newer