From 80b2efbea7592fa273c8956fea1355001cc0e3ef Mon Sep 17 00:00:00 2001 From: MerryMage Date: Wed, 21 Dec 2016 20:37:15 +0000 Subject: [PATCH] callbacks: Add documentation --- include/dynarmic/callbacks.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/dynarmic/callbacks.h b/include/dynarmic/callbacks.h index 0ec6436b..3eb58f6a 100644 --- a/include/dynarmic/callbacks.h +++ b/include/dynarmic/callbacks.h @@ -16,25 +16,36 @@ class Jit; /// These function pointers may be inserted into compiled code. struct UserCallbacks { + // Reads through these callbacks may not be aligned. + // Memory must be interpreted as if ENDIANSTATE == 0, endianness will be corrected by the JIT. std::uint8_t (*MemoryRead8)(std::uint32_t vaddr); std::uint16_t (*MemoryRead16)(std::uint32_t vaddr); std::uint32_t (*MemoryRead32)(std::uint32_t vaddr); std::uint64_t (*MemoryRead64)(std::uint32_t vaddr); + // Writes through these callbacks may not be aligned. + // Memory must be interpreted as if ENDIANSTATE == 0, endianness will be corrected by the JIT. void (*MemoryWrite8)(std::uint32_t vaddr, std::uint8_t value); void (*MemoryWrite16)(std::uint32_t vaddr, std::uint16_t value); void (*MemoryWrite32)(std::uint32_t vaddr, std::uint32_t value); void (*MemoryWrite64)(std::uint32_t vaddr, std::uint64_t value); + // If this callback returns true, the JIT will assume MemoryRead* callbacks will always + // return the same value at any point in time for this vaddr. The JIT may use this information + // in optimizations. + // An conservative implementation that always returns false is safe. bool (*IsReadOnlyMemory)(std::uint32_t vaddr); /// The intrepreter must execute only one instruction at PC. void (*InterpreterFallback)(std::uint32_t pc, Jit* jit, void* user_arg); void* user_arg = nullptr; + // This callback is called whenever a SVC instruction is executed. void (*CallSVC)(std::uint32_t swi); // Page Table + // The page table is used for faster memory access. If an entry in the table is nullptr, + // the JIT will fallback to calling the MemoryRead*/MemoryWrite* callbacks. static constexpr std::size_t PAGE_BITS = 12; static constexpr std::size_t NUM_PAGE_TABLE_ENTRIES = 1 << (32 - PAGE_BITS); std::array* page_table = nullptr;