diff options
author | 2022-02-04 18:15:16 -0900 | |
---|---|---|
committer | 2022-02-04 22:15:16 -0500 | |
commit | 09c4c23136172b40f37cfed3b08f182dccac12d4 (patch) | |
tree | 1b7e171a9679697b854556852058ff11d80d9a48 /src/devices/bus | |
parent | fff6c5e9fd910f4f20bd7ba0c8f40a8700ccc16c (diff) |
nes_slot.cpp: Unified CHR banking into a common function. (#9261)
* nes_slot.cpp: Unified CHR banking into a common function.
- Removed PPU_MIRROR_NONE as an option for nametable mirroring.
- Shrunk over-allocated 4-screen NT RAM to correct 4K size.
- Sundry minor clean ups.
- Only calculate start of bank once.
Diffstat (limited to 'src/devices/bus')
-rw-r--r-- | src/devices/bus/nes/mmc3_clones.cpp | 9 | ||||
-rw-r--r-- | src/devices/bus/nes/nes_slot.cpp | 189 | ||||
-rw-r--r-- | src/devices/bus/nes/nes_slot.h | 41 |
3 files changed, 78 insertions, 161 deletions
diff --git a/src/devices/bus/nes/mmc3_clones.cpp b/src/devices/bus/nes/mmc3_clones.cpp index 6b8807175e7..b9a989c78e0 100644 --- a/src/devices/bus/nes/mmc3_clones.cpp +++ b/src/devices/bus/nes/mmc3_clones.cpp @@ -2678,12 +2678,11 @@ void nes_bmc_jy208_device::write_m(offs_t offset, u8 data) nes_bmc_hik8_device::write_m(offset, data); if (BIT(m_reg[2], 6)) - { - set_nt_mirroring(PPU_MIRROR_4SCREEN); // actually change NT pointers - m_mirroring = PPU_MIRROR_4SCREEN; // prevent MMC3 mirror switching - } + m_mirroring = PPU_MIRROR_4SCREEN; // prevent MMC3 mirror switching else - m_mirroring = PPU_MIRROR_NONE; // allow MMC3 mirror switching + m_mirroring = BIT(m_mmc_mirror, 0) ? PPU_MIRROR_HORZ : PPU_MIRROR_VERT; // allow MMC3 mirror switching and get its current setting + + set_nt_mirroring(m_mirroring); // actually change nametable pointers } /*------------------------------------------------- diff --git a/src/devices/bus/nes/nes_slot.cpp b/src/devices/bus/nes/nes_slot.cpp index 54709f4b03e..aee85bbb2a5 100644 --- a/src/devices/bus/nes/nes_slot.cpp +++ b/src/devices/bus/nes/nes_slot.cpp @@ -130,7 +130,7 @@ device_nes_cart_interface::device_nes_cart_interface(const machine_config &mconf , m_outer_prg_size(0) , m_outer_chr_size(0) , m_smd133_addr(0x6000) - , m_mirroring(PPU_MIRROR_NONE) + , m_mirroring(PPU_MIRROR_HORZ) , m_pcb_ctrl_mirror(false) , m_four_screen_vram(false) , m_has_trainer(false) @@ -174,26 +174,24 @@ void device_nes_cart_interface::prg_alloc(size_t size, const char *tag) m_prg_chunks--; } - m_prg_mask = ((m_prg_chunks << 1) - 1); + m_prg_mask = (m_prg_chunks << 1) - 1; // printf("first mask %x!\n", m_prg_mask); if ((m_prg_chunks << 1) & m_prg_mask) { - int mask_bits = 0, temp = (m_prg_chunks << 1), mapsize; + int mask_bits = 0; // contrary to what happens with later systems, like e.g. SNES or MD, // only half a dozen of NES carts have PRG which is not a power of 2 // so we use this bank_map only as an exception // printf("uneven rom!\n"); // 1. redefine mask as (next power of 2)-1 - for (; temp; ) - { + for (int temp = m_prg_chunks << 1; temp; temp >>= 1) mask_bits++; - temp >>= 1; - } + m_prg_mask = (1 << mask_bits) - 1; // printf("new mask %x!\n", m_prg_mask); - mapsize = (1 << mask_bits)/2; + int mapsize = (1 << mask_bits) / 2; // 2. create a bank_map for banks in the range mask/2 -> mask m_prg_bank_map.resize(mapsize); @@ -206,7 +204,7 @@ void device_nes_cart_interface::prg_alloc(size_t size, const char *tag) while (j % mapsize) { int k = 0, repeat_banks; - while ((j % (mapsize >> k)) && k < mask_bits) + while (j % (mapsize >> k) && k < mask_bits) k++; repeat_banks = j % (mapsize >> (k - 1)); for (int l = 0; l < repeat_banks; l++) @@ -271,20 +269,20 @@ void device_nes_cart_interface::battery_alloc(size_t size) inline int device_nes_cart_interface::prg_8k_bank_num(int bank_8k) { - if (m_prg_mask == ((m_prg_chunks << 1) - 1)) + if (m_prg_mask == (m_prg_chunks << 1) - 1) return bank_8k & m_prg_mask; // only a few pirate games (less than a dozen) have PRG which is not power of 2 // so we treat it here separately, rather than forcing all games to use m_prg_bank_map // case 1: if we are accessing a bank before the end of the image, just return that bank - if (bank_8k < ((m_prg_chunks << 1) - 1)) + if (bank_8k < (m_prg_chunks << 1) - 1) return bank_8k; // case 2: otherwise return a mirror using the bank_map! // uint8_t temp = bank_8k; bank_8k &= m_prg_mask; - bank_8k -= (m_prg_mask/2 + 1); + bank_8k -= m_prg_mask / 2 + 1; // printf("bank: accessed %x (top: %x), returned %x\n", temp, (m_prg_chunks << 1) - 1, m_prg_bank_map[bank_8k]); return m_prg_bank_map[bank_8k]; } @@ -303,11 +301,11 @@ inline void device_nes_cart_interface::update_prg_banks(int prg_bank_start, int void device_nes_cart_interface::prg32(int bank) { - /* if there is only 16k PRG, return */ + // if there is only 16k PRG, return if (!(m_prg_chunks >> 1)) return; - /* assumes that bank references a 32k chunk */ + // assumes that bank references a 32k chunk bank = prg_8k_bank_num(bank * 4); m_prg_bank[0] = bank + 0; @@ -319,7 +317,7 @@ void device_nes_cart_interface::prg32(int bank) void device_nes_cart_interface::prg16_89ab(int bank) { - /* assumes that bank references a 16k chunk */ + // assumes that bank references a 16k chunk bank = prg_8k_bank_num(bank * 2); m_prg_bank[0] = bank + 0; @@ -329,7 +327,7 @@ void device_nes_cart_interface::prg16_89ab(int bank) void device_nes_cart_interface::prg16_cdef(int bank) { - /* assumes that bank references a 16k chunk */ + // assumes that bank references a 16k chunk bank = prg_8k_bank_num(bank * 2); m_prg_bank[2] = bank + 0; @@ -353,110 +351,36 @@ void device_nes_cart_interface::prg8_x(int start, int bank) // CHR helpers //------------------------------------------------- -inline void device_nes_cart_interface::chr_sanity_check( int source ) +void device_nes_cart_interface::bank_chr(int shift, int start, int bank, int source) { - if (source == CHRRAM && m_vram.empty()) - fatalerror("CHRRAM bankswitch with no VRAM\n"); - - if (source == CHRROM && m_vrom == nullptr) - fatalerror("CHRROM bankswitch with no VROM\n"); -} - -void device_nes_cart_interface::chr8(int bank, int source) -{ - chr_sanity_check(source); + uint8_t *base_ptr; + uint32_t chr_chunks; if (source == CHRRAM) { - bank &= (m_vram_chunks - 1); - for (int i = 0; i < 8; i++) - { - m_chr_src[i] = source; - m_chr_orig[i] = (bank * 0x2000) + (i * 0x400); // for save state uses! - m_chr_access[i] = &m_vram[m_chr_orig[i]]; - } - } - else - { - bank &= (m_vrom_chunks - 1); - for (int i = 0; i < 8; i++) - { - m_chr_src[i] = source; - m_chr_orig[i] = (bank * 0x2000) + (i * 0x400); // for save state uses! - m_chr_access[i] = &m_vrom[m_chr_orig[i]]; - } - } -} + assert(!m_vram.empty()); -void device_nes_cart_interface::chr4_x(int start, int bank, int source) -{ - chr_sanity_check(source); - - if (source == CHRRAM) - { - bank &= ((m_vram_chunks << 1) - 1); - for (int i = 0; i < 4; i++) - { - m_chr_src[i + start] = source; - m_chr_orig[i + start] = (bank * 0x1000) + (i * 0x400); // for save state uses! - m_chr_access[i + start] = &m_vram[m_chr_orig[i + start]]; - } + base_ptr = &m_vram[0]; + chr_chunks = m_vram_chunks; } - else + else // source == CHRROM { - bank &= ((m_vrom_chunks << 1) - 1); - for (int i = 0; i < 4; i++) - { - m_chr_src[i + start] = source; - m_chr_orig[i + start] = (bank * 0x1000) + (i * 0x400); // for save state uses! - m_chr_access[i + start] = &m_vrom[m_chr_orig[i + start]]; - } - } -} + assert(m_vrom != nullptr); -void device_nes_cart_interface::chr2_x(int start, int bank, int source) -{ - chr_sanity_check(source); - - if (source == CHRRAM) - { - bank &= ((m_vram_chunks << 2) - 1); - for (int i = 0; i < 2; i++) - { - m_chr_src[i + start] = source; - m_chr_orig[i + start] = (bank * 0x800) + (i * 0x400); // for save state uses! - m_chr_access[i + start] = &m_vram[m_chr_orig[i + start]]; - } + base_ptr = m_vrom; + chr_chunks = m_vrom_chunks; } - else - { - bank &= ((m_vrom_chunks << 2) - 1); - for (int i = 0; i < 2; i++) - { - m_chr_src[i + start] = source; - m_chr_orig[i + start] = (bank * 0x800) + (i * 0x400); // for save state uses! - m_chr_access[i + start] = &m_vrom[m_chr_orig[i + start]]; - } - } -} -void device_nes_cart_interface::chr1_x(int start, int bank, int source) -{ - chr_sanity_check(source); + bank &= (chr_chunks << (3 - shift)) - 1; + int size = 0x400 << shift; + int bank_start = bank * size; + int kbyte = 1 << shift; - if (source == CHRRAM) - { - bank &= ((m_vram_chunks << 3) - 1); - m_chr_src[start] = source; - m_chr_orig[start] = (bank * 0x400); // for save state uses! - m_chr_access[start] = &m_vram[m_chr_orig[start]]; - } - else + for (int i = 0; i < kbyte; i++) { - bank &= ((m_vrom_chunks << 3) - 1); - m_chr_src[start] = source; - m_chr_orig[start] = (bank * 0x400); // for save state uses! - m_chr_access[start] = &m_vrom[m_chr_orig[start]]; + m_chr_src[i + start] = source; + m_chr_orig[i + start] = bank_start + i * 0x400; // for save state uses! + m_chr_access[i + start] = &base_ptr[m_chr_orig[i + start]]; } } @@ -466,7 +390,7 @@ void device_nes_cart_interface::chr1_x(int start, int bank, int source) void device_nes_cart_interface::set_nt_page(int page, int source, int bank, int writable) { - uint8_t* base_ptr; + uint8_t *base_ptr; switch (source) { @@ -474,7 +398,7 @@ void device_nes_cart_interface::set_nt_page(int page, int source, int bank, int base_ptr = &m_ext_ntram[0]; break; case VROM: - bank &= ((m_vrom_chunks << 3) - 1); + bank &= (m_vrom_chunks << 3) - 1; base_ptr = m_vrom; break; case EXRAM: @@ -487,7 +411,7 @@ void device_nes_cart_interface::set_nt_page(int page, int source, int bank, int break; } - page &= 3; /* mask down to the 4 logical pages */ + page &= 3; // mask down to the 4 logical pages m_nt_src[page] = source; if (base_ptr) @@ -501,20 +425,21 @@ void device_nes_cart_interface::set_nt_page(int page, int source, int bank, int void device_nes_cart_interface::set_nt_mirroring(int mirroring) { - /* setup our videomem handlers based on mirroring */ + // setup our videomem handlers based on mirroring switch (mirroring) { - case PPU_MIRROR_VERT: + default: + case PPU_MIRROR_HORZ: set_nt_page(0, CIRAM, 0, 1); - set_nt_page(1, CIRAM, 1, 1); - set_nt_page(2, CIRAM, 0, 1); + set_nt_page(1, CIRAM, 0, 1); + set_nt_page(2, CIRAM, 1, 1); set_nt_page(3, CIRAM, 1, 1); break; - case PPU_MIRROR_HORZ: + case PPU_MIRROR_VERT: set_nt_page(0, CIRAM, 0, 1); - set_nt_page(1, CIRAM, 0, 1); - set_nt_page(2, CIRAM, 1, 1); + set_nt_page(1, CIRAM, 1, 1); + set_nt_page(2, CIRAM, 0, 1); set_nt_page(3, CIRAM, 1, 1); break; @@ -539,14 +464,6 @@ void device_nes_cart_interface::set_nt_mirroring(int mirroring) set_nt_page(2, CART_NTRAM, 2, 1); set_nt_page(3, CART_NTRAM, 3, 1); break; - - case PPU_MIRROR_NONE: - default: - set_nt_page(0, CIRAM, 0, 1); - set_nt_page(1, CIRAM, 0, 1); - set_nt_page(2, CIRAM, 1, 1); - set_nt_page(3, CIRAM, 1, 1); - break; } } @@ -623,7 +540,7 @@ uint8_t device_nes_cart_interface::chr_r(offs_t offset) void device_nes_cart_interface::nt_w(offs_t offset, uint8_t data) { - int page = ((offset & 0xc00) >> 10); + int page = (offset & 0xc00) >> 10; if (!m_nt_writable[page]) return; @@ -633,7 +550,7 @@ void device_nes_cart_interface::nt_w(offs_t offset, uint8_t data) uint8_t device_nes_cart_interface::nt_r(offs_t offset) { - int page = ((offset & 0xc00) >> 10); + int page = (offset & 0xc00) >> 10; return m_nt_access[page][offset & 0x3ff]; } @@ -708,7 +625,7 @@ void device_nes_cart_interface::pcb_start(running_machine &machine, uint8_t *cir if (m_four_screen_vram) { - m_ext_ntram.resize(0x2000); + m_ext_ntram.resize(0x1000); device().save_item(NAME(m_ext_ntram)); } @@ -803,7 +720,7 @@ void nes_cart_slot_device::pcb_reset() -------------------------------------------------*/ -/* Include emulation of NES PCBs for softlist */ +// Include emulation of NES PCBs for softlist #include "nes_pcb.hxx" @@ -813,7 +730,7 @@ void nes_cart_slot_device::pcb_reset() -------------------------------------------------*/ -/* Include emulation of UNIF Boards for .unf files */ +// Include emulation of UNIF Boards for .unf files #include "nes_unif.hxx" @@ -823,7 +740,7 @@ void nes_cart_slot_device::pcb_reset() -------------------------------------------------*/ -/* Include emulation of iNES Mappers for .nes files */ +// Include emulation of iNES Mappers for .nes files #include "nes_ines.hxx" @@ -835,11 +752,11 @@ image_init_result nes_cart_slot_device::call_load() { char magic[4]; - /* Check first 4 bytes of the image to decide if it is UNIF or iNES */ - /* Unfortunately, many .unf files have been released as .nes, so we cannot rely on extensions only */ + // Check first 4 bytes of the image to decide if it is UNIF or iNES + // Unfortunately, many .unf files have been released as .nes, so we cannot rely on extensions only fread(magic, 4); - if ((magic[0] == 'N') && (magic[1] == 'E') && (magic[2] == 'S')) /* If header starts with 'NES' it is iNES */ + if ((magic[0] == 'N') && (magic[1] == 'E') && (magic[2] == 'S')) // If header starts with 'NES' it is iNES { if (length() <= 0x10) { @@ -849,7 +766,7 @@ image_init_result nes_cart_slot_device::call_load() call_load_ines(); } - else if ((magic[0] == 'U') && (magic[1] == 'N') && (magic[2] == 'I') && (magic[3] == 'F')) /* If header starts with 'UNIF' it is UNIF */ + else if ((magic[0] == 'U') && (magic[1] == 'N') && (magic[2] == 'I') && (magic[3] == 'F')) // If header starts with 'UNIF' it is UNIF { if (length() <= 0x20) { diff --git a/src/devices/bus/nes/nes_slot.h b/src/devices/bus/nes/nes_slot.h index 8c0b6efa3ce..5ae61d5a643 100644 --- a/src/devices/bus/nes/nes_slot.h +++ b/src/devices/bus/nes/nes_slot.h @@ -170,7 +170,6 @@ enum #define CART_NTRAM 4 -#define PPU_MIRROR_NONE 0 #define PPU_MIRROR_VERT 1 #define PPU_MIRROR_HORZ 2 #define PPU_MIRROR_HIGH 3 @@ -334,7 +333,6 @@ public: // CHR int m_chr_source; // global source for the 8 VROM banks - inline void chr_sanity_check(int source); //these were previously called chr_map. they are a quick banking structure, //because some of these change multiple times per scanline! @@ -346,24 +344,27 @@ public: uint32_t m_vram_chunks; // CHR helpers - void chr8(int bank, int source); - void chr4_x(int start, int bank, int source); - void chr4_0(int bank, int source) { chr4_x(0, bank, source); } - void chr4_4(int bank, int source) { chr4_x(4, bank, source); } - void chr2_x(int start, int bank, int source); - void chr2_0(int bank, int source) { chr2_x(0, bank, source); } - void chr2_2(int bank, int source) { chr2_x(2, bank, source); } - void chr2_4(int bank, int source) { chr2_x(4, bank, source); } - void chr2_6(int bank, int source) { chr2_x(6, bank, source); } - void chr1_x(int start, int bank, int source); - void chr1_0(int bank, int source) { chr1_x(0, bank, source); } - void chr1_1(int bank, int source) { chr1_x(1, bank, source); } - void chr1_2(int bank, int source) { chr1_x(2, bank, source); } - void chr1_3(int bank, int source) { chr1_x(3, bank, source); } - void chr1_4(int bank, int source) { chr1_x(4, bank, source); } - void chr1_5(int bank, int source) { chr1_x(5, bank, source); } - void chr1_6(int bank, int source) { chr1_x(6, bank, source); } - void chr1_7(int bank, int source) { chr1_x(7, bank, source); } +private: + void bank_chr(int shift, int start, int bank, int source); +public: + void chr8(int bank, int source) { bank_chr(3, 0, bank, source); } + void chr4_x(int start, int bank, int source) { bank_chr(2, start, bank, source); } + void chr4_0(int bank, int source) { bank_chr(2, 0, bank, source); } + void chr4_4(int bank, int source) { bank_chr(2, 4, bank, source); } + void chr2_x(int start, int bank, int source) { bank_chr(1, start, bank, source); } + void chr2_0(int bank, int source) { bank_chr(1, 0, bank, source); } + void chr2_2(int bank, int source) { bank_chr(1, 2, bank, source); } + void chr2_4(int bank, int source) { bank_chr(1, 4, bank, source); } + void chr2_6(int bank, int source) { bank_chr(1, 6, bank, source); } + void chr1_x(int start, int bank, int source) { bank_chr(0, start, bank, source); } + void chr1_0(int bank, int source) { bank_chr(0, 0, bank, source); } + void chr1_1(int bank, int source) { bank_chr(0, 1, bank, source); } + void chr1_2(int bank, int source) { bank_chr(0, 2, bank, source); } + void chr1_3(int bank, int source) { bank_chr(0, 3, bank, source); } + void chr1_4(int bank, int source) { bank_chr(0, 4, bank, source); } + void chr1_5(int bank, int source) { bank_chr(0, 5, bank, source); } + void chr1_6(int bank, int source) { bank_chr(0, 6, bank, source); } + void chr1_7(int bank, int source) { bank_chr(0, 7, bank, source); } // NameTable & Mirroring |