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  1. Nov 14, 2021
    • Geo Ster's avatar
      Implement first FPU instruction · 9444ba92
      Geo Ster authored
      * Since we have encountered our first FPU register, add the 32 floating
      point registers to the CPU.
      
      * In addition solve a small bug in the JAL instruction related to the
      return link address. See previous commit for details
      9444ba92
    • Geo Ster's avatar
      Move header files to src dir · 9969bd6f
      Geo Ster authored
      * Having the header files in a seperate dir is only useful when developing
      libraries that are meant to be used by other programs. In our case though
      it makes the file structure more tedious so gather everything in one place.
      9969bd6f
    • Geo Ster's avatar
      Migrate to fmt for logging · 035008f7
      Geo Ster authored
      * std::cout is not fit for our usecase, which is format heavy output.
      This results in a lot of code bloat from switching between std::dec and
      std::hex. Switching to fmt yields significantly cleaner code.
      035008f7
  2. Nov 13, 2021
    • Geo Ster's avatar
      Remove dependency on int128 · 5cafeb61
      Geo Ster authored
      * This is only supported on GCC/Clang making compilation fail on
      MSVC. In addition we don't really need this since accessing the
      entire 128bit register is very rare and can be emulated by setting
      each of 64bit parts seperately.
      5cafeb61
    • Geo Ster's avatar
      Implement more instructions in the CPU · 2daed618
      Geo Ster authored
      * Nothing special really, just adding more instructions and fixes minor
      bugs to progress further
      2daed618
  3. Nov 04, 2021
    • Geo Ster's avatar
      Add scratchpad handler · 49a61fb1
      Geo Ster authored
      * Currently the BIOS tries to write something to scratchpad and it fails
      because its address is not our currently supported range. So add a new buffer
      for the 16KB scratchpad used by the CPU and add a function to use it if the
      address is in the correct range.
      
      * Also shorten some function names and change some array to C-style because we
      like to work with pointers and STL doesn't like that.
      49a61fb1
    • Geo Ster's avatar
      Implement MADD1/MTC0/JALR/SD and rewrite COP0 decoding · e2559bb5
      Geo Ster authored
      * COP0 instructions sadly have way too many encoding to use a single template one them,
      so rewrite the decoder to manually extract the required bits for each instruction. This
      fixes a bug where the MTC0 instruction was mistaken for MFC0.
      
      * Implement more instructions so we can execute more of the BIOS. In addition fix
      an oopsie in the ORI instruction which fixes some bugged memory writes. As of now the
      BIOS tries to write address 0x70003fe0 which maps to the scratchpad memory (assuming no further
      logic errors are present). Need to investigate why this is and how to emulate it before
      continuing...
      e2559bb5
  4. Nov 03, 2021
    • Geo Ster's avatar
      Implement ORI/ADDI/LQ · ebf1986d
      Geo Ster authored
      In addition:
      * Correct register notation (word refers to a 32bit quantity not 16bit)
      * Simplify sign extension casing
      * Add more useful logging
      ebf1986d
  5. Oct 31, 2021
    • Geo Ster's avatar
      Implement read/write operations and KUSEG regions · 8653f76f
      Geo Ster authored
      * Now that the BIOS is loaded we can start executing it!
      The starting address the EE uses is 0xbfc00000 which maps
      to KUSEG1. Since all KUSEG regions except KUSEG2 are mirrors
      of each other we only need to translate the address to the
      KUSEG appropriate.
      
      * The functional differences between KUSEG0/1 are minimal and
      very niche so I won't bother emulating them now. Address wise
      we can notice that the only difference between addresses is the
      most significant half byte. By using that byte as an index in
      a mask table we can define an appropriate mask for each KUSEG
      address. Idea taken from a very handy PSX document I discovered
      last year [1]
      
      [1] https://svkt.org/~simias/guide.pdf (43)
      8653f76f
    • Geo Ster's avatar
      Add initial memory map · a54398cc
      Geo Ster authored
      * The ps2tek documentation states the memory map clearly [1].
      It seems to have a similar architecture with the PSX, where
      the main memory map (KUSEG0) is mirrored in multiple regions
      (KUSEG1/KUSEG2) with different access patterns for each region.
      For now we don't have to emulate all of them, just the main
      memory map.
      
      * Allocate the entire 512MB memory into an array and make a convenient
      struct to abstract memory range operations.
      
      [1] https://psi-rockin.github.io/ps2tek/#memorymap
      a54398cc
    • Geo Ster's avatar
      Add initial EE/Bus implementations · 2ad0640f
      Geo Ster authored
      * This commit adds a most basic CPU class that acts as a template
      which we will slowly build.
      
      * The architecture is pretty simple; the ComponentManager will create all
      the seperate components (EE, VP, IOP, GS etc) as unique_ptr's since
      it owns them and only it has access to them. All the other components
      must pass through the manager to read/write data to memory.
      To achieve this they are given a pointer to the ComponentManger in their constructor.
      
      * For now the CPU directly accesses the bios which shouldn't
      happen but will be fixed eventually when I implement generic
      read/writes. The goal is to start implementing the CPU as fast as
      possible in order to get to the GPU/VPU's and display something!
      2ad0640f
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