AudioCore: Skeleton Implementation

This commit:
* Adds a new subproject, audio_core.
* Defines structures that exist in DSP shared memory.
* Hooks up various other parts of the emulator into audio core.

This sets the foundation for a later HLE DSP implementation.

1 files changed, 55 insertions, 0 deletions

diff --git a/src/audio_core/hle/pipe.cpp b/src/audio_core/hle/pipe.cpp
new file mode 100644
index 000000000..6542c760c
--- /dev/null
+++ b/src/audio_core/hle/pipe.cpp
@@ -0,0 +1,55 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <vector>
+
+#include "audio_core/hle/pipe.h"
+
+#include "common/common_types.h"
+#include "common/logging/log.h"
+
+namespace DSP {
+namespace HLE {
+
+static size_t pipe2position = 0;
+
+void ResetPipes() {
+    pipe2position = 0;
+}
+
+std::vector<u8> PipeRead(u32 pipe_number, u32 length) {
+    if (pipe_number != 2) {
+        LOG_WARNING(Audio_DSP, "pipe_number = %u (!= 2), unimplemented", pipe_number);
+        return {}; // We currently don't handle anything other than the audio pipe.
+    }
+
+    // Canned DSP responses that games expect. These were taken from HW by 3dmoo team.
+    // TODO: Our implementation will actually use a slightly different response than this one.
+    // TODO: Use offsetof on DSP structures instead for a proper response.
+    static const std::array<u8, 32> canned_response {{
+        0x0F, 0x00, 0xFF, 0xBF, 0x8E, 0x9E, 0x80, 0x86, 0x8E, 0xA7, 0x30, 0x94, 0x00, 0x84, 0x40, 0x85,
+        0x8E, 0x94, 0x10, 0x87, 0x10, 0x84, 0x0E, 0xA9, 0x0E, 0xAA, 0xCE, 0xAA, 0x4E, 0xAC, 0x58, 0xAC
+    }};
+
+    // TODO: Move this into dsp::DSP service since it happens on the service side.
+    // Hardware observation: No data is returned if requested length reads beyond the end of the data in-pipe.
+    if (pipe2position + length > canned_response.size()) {
+        return {};
+    }
+
+    std::vector<u8> ret;
+    for (size_t i = 0; i < length; i++, pipe2position++) {
+        ret.emplace_back(canned_response[pipe2position]);
+    }
+
+    return ret;
+}
+
+void PipeWrite(u32 pipe_number, const std::vector<u8>& buffer) {
+    // TODO: proper pipe behaviour
+}
+
+} // namespace HLE
+} // namespace DSP