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MMC1 512K PRG support #396

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28ab2c9
MMC1 512K PRG support
sebastienvezina Apr 28, 2025
17b9b48
Fixed double __ in register names
sebastienvezina Apr 28, 2025
88e2cb5
vscode plugin ignore - not needed
sebastienvezina Apr 28, 2025
a00393e
skip set CHR bits if switch to bank < 16
sebastienvezina Apr 28, 2025
9993ac2
fix switching to a high bank was exiting early in the middle of the b…
sebastienvezina Apr 28, 2025
d11ec30
replaced cmp/bne w and/beq
sebastienvezina Apr 28, 2025
085fec1
update actual registers
sebastienvezina Apr 28, 2025
659a4a0
nes-mmc1 prg 512 unit tests
sebastienvezina Apr 28, 2025
2610b30
hex to lowercase + removed references to prg 15
sebastienvezina Apr 28, 2025
cc334b9
jrowboy's set_prg_bank
sebastienvezina Apr 29, 2025
af1dc55
review https://github.com/llvm-mos/llvm-mos-sdk/pull/396#discussion_r…
sebastienvezina Apr 29, 2025
1661294
fix https://github.com/llvm-mos/llvm-mos-sdk/pull/396#discussion_r206…
sebastienvezina Apr 29, 2025
a93c409
fix https://github.com/llvm-mos/llvm-mos-sdk/pull/396#discussion_r206…
sebastienvezina Apr 29, 2025
48992f0
latest version of set_prg_bank but still use prg_rom_is_512 which sho…
sebastienvezina Apr 29, 2025
a1a1df2
attempt at fixing the fixed bank output format
sebastienvezina Apr 29, 2025
ed2856d
added __ prefix to prg_rom_is_512
sebastienvezina Apr 29, 2025
181ecda
try to preserve the PRG RAM bit
sebastienvezina Apr 29, 2025
500564c
Added prg-rom-512 test to list
sebastienvezina Apr 30, 2025
b62a60f
banked_call fiddling because set_prg_bank clobbers rc2 and/or rc3
sebastienvezina May 5, 2025
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28 changes: 28 additions & 0 deletions mos-platform/nes-mmc1/mapper.s
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Original file line number Diff line number Diff line change
Expand Up @@ -101,6 +101,34 @@ __set_prg_bank:
set_prg_bank:
tay
.Lset:
lda _PRG_BANK ; Load the value of _PRG_BANK into the accumulator
and #%00010000 ; Compare it with 16
beq set_bits_to_0 ; If _PRG_BANK is less than 16, branch to set_bits_to_0

.set_bits_to_1:
lda _CHR_BANK0 ; Load the value of _CHR_BANK0
ora #%00010000 ; Set the 4th bit
sta _CHR_BANK0 ; Store the updated value back
mmc1_register_write MMC1_CHR0

lda _CHR_BANK1 ; Load the value of _CHR_BANK1
ora #%00010000 ; Set the 4th bit
sta _CHR_BANK1 ; Store the updated value back
mmc1_register_write MMC1_CHR1
bne .continue_bankswitch

.set_bits_to_0:
lda _CHR_BANK0 ; Load the value of _CHR_BANK0
and #%11101111 ; Clear the 4th bit
sta _CHR_BANK0 ; Store the updated value back
mmc1_register_write MMC1_CHR0

lda _CHR_BANK1 ; Load the value of _CHR_BANK1
and #%11101111 ; Clear the 4th bit
sta _CHR_BANK1 ; Store the updated value back
mmc1_register_write MMC1_CHR1

.continue_bankswitch:
inc __reset_mmc1_byte
ldx #1
stx _IN_PROGRESS
Expand Down
84 changes: 83 additions & 1 deletion mos-platform/nes-mmc1/prg-rom-banked.ld
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,22 @@ __prg_rom_11_lma = 0x0b8000;
__prg_rom_12_lma = 0x0c8000;
__prg_rom_13_lma = 0x0d8000;
__prg_rom_14_lma = 0x0e8000;
__prg_rom_15_lma = 0x0f8000;
__prg_rom_16_lma = 0x108000;
__prg_rom_17_lma = 0x118000;
__prg_rom_18_lma = 0x128000;
__prg_rom_19_lma = 0x138000;
__prg_rom_20_lma = 0x148000;
__prg_rom_21_lma = 0x158000;
__prg_rom_22_lma = 0x168000;
__prg_rom_23_lma = 0x178000;
__prg_rom_24_lma = 0x188000;
__prg_rom_25_lma = 0x198000;
__prg_rom_26_lma = 0x1A8000;
__prg_rom_27_lma = 0x1B8000;
__prg_rom_28_lma = 0x1C8000;
__prg_rom_29_lma = 0x1D8000;
__prg_rom_30_lma = 0x1E8000;
__prg_rom_fixed_lma = 0xc000;

__prg_rom_0_offset = 0x00000;
Expand All @@ -32,6 +48,22 @@ __prg_rom_11_offset = 0x2c000;
__prg_rom_12_offset = 0x30000;
__prg_rom_13_offset = 0x34000;
__prg_rom_14_offset = 0x38000;
__prg_rom_15_offset = 0x3C000;
__prg_rom_16_offset = 0x40000;
__prg_rom_17_offset = 0x44000;
__prg_rom_18_offset = 0x48000;
__prg_rom_19_offset = 0x4c000;
__prg_rom_20_offset = 0x50000;
__prg_rom_21_offset = 0x54000;
__prg_rom_22_offset = 0x58000;
__prg_rom_23_offset = 0x5c000;
__prg_rom_24_offset = 0x60000;
__prg_rom_25_offset = 0x64000;
__prg_rom_26_offset = 0x68000;
__prg_rom_27_offset = 0x6c000;
__prg_rom_28_offset = 0x70000;
__prg_rom_29_offset = 0x74000;
__prg_rom_30_offset = 0x78000;
__prg_rom_fixed_offset = __prg_rom_size * 1024 - 0x4000;

MEMORY {
Expand All @@ -51,6 +83,22 @@ MEMORY {
prg_rom_12 : ORIGIN = __prg_rom_12_lma, LENGTH = __prg_rom_size >= 256 ? 0x4000 - 12 : 0
prg_rom_13 : ORIGIN = __prg_rom_13_lma, LENGTH = __prg_rom_size >= 256 ? 0x4000 - 12 : 0
prg_rom_14 : ORIGIN = __prg_rom_14_lma, LENGTH = __prg_rom_size >= 256 ? 0x4000 - 12 : 0
prg_rom_15 : ORIGIN = __prg_rom_15_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_16 : ORIGIN = __prg_rom_16_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_17 : ORIGIN = __prg_rom_17_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_18 : ORIGIN = __prg_rom_18_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_19 : ORIGIN = __prg_rom_19_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_20 : ORIGIN = __prg_rom_20_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_21 : ORIGIN = __prg_rom_21_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_22 : ORIGIN = __prg_rom_22_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_23 : ORIGIN = __prg_rom_23_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_24 : ORIGIN = __prg_rom_24_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_25 : ORIGIN = __prg_rom_25_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_26 : ORIGIN = __prg_rom_26_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_27 : ORIGIN = __prg_rom_27_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_28 : ORIGIN = __prg_rom_28_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_29 : ORIGIN = __prg_rom_29_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_30 : ORIGIN = __prg_rom_30_lma, LENGTH = __prg_rom_size >= 512 ? 0x4000 - 12 : 0
prg_rom_fixed : ORIGIN = __prg_rom_fixed_lma, LENGTH = 0x4000 - 12

/* Reset stub. Arbitrarily put its VMA in the first bank. */
Expand Down Expand Up @@ -78,6 +126,22 @@ SECTIONS {
.prg_rom_12 : { *(.prg_rom_12 .prg_rom_12.*) } >prg_rom_12
.prg_rom_13 : { *(.prg_rom_13 .prg_rom_13.*) } >prg_rom_13
.prg_rom_14 : { *(.prg_rom_14 .prg_rom_14.*) } >prg_rom_14
.prg_rom_15 : { *(.prg_rom_15 .prg_rom_15.*) } >prg_rom_15
.prg_rom_16 : { *(.prg_rom_16 .prg_rom_16.*) } >prg_rom_16
.prg_rom_17 : { *(.prg_rom_17 .prg_rom_17.*) } >prg_rom_17
.prg_rom_18 : { *(.prg_rom_18 .prg_rom_18.*) } >prg_rom_18
.prg_rom_19 : { *(.prg_rom_19 .prg_rom_19.*) } >prg_rom_19
.prg_rom_20 : { *(.prg_rom_20 .prg_rom_20.*) } >prg_rom_20
.prg_rom_21 : { *(.prg_rom_21 .prg_rom_21.*) } >prg_rom_21
.prg_rom_22 : { *(.prg_rom_22 .prg_rom_22.*) } >prg_rom_22
.prg_rom_23 : { *(.prg_rom_23 .prg_rom_23.*) } >prg_rom_23
.prg_rom_24 : { *(.prg_rom_24 .prg_rom_24.*) } >prg_rom_24
.prg_rom_25 : { *(.prg_rom_25 .prg_rom_25.*) } >prg_rom_25
.prg_rom_26 : { *(.prg_rom_26 .prg_rom_26.*) } >prg_rom_26
.prg_rom_27 : { *(.prg_rom_27 .prg_rom_27.*) } >prg_rom_27
.prg_rom_28 : { *(.prg_rom_28 .prg_rom_28.*) } >prg_rom_28
.prg_rom_29 : { *(.prg_rom_29 .prg_rom_29.*) } >prg_rom_29
.prg_rom_30 : { *(.prg_rom_30 .prg_rom_30.*) } >prg_rom_30
.prg_rom_fixed : { *(.prg_rom_fixed .prg_rom_fixed.*) } >prg_rom_fixed
}

Expand All @@ -88,7 +152,7 @@ SECTIONS {
.reset_fixed : { KEEP(*(.reset_fixed)) } >reset_fixed
}

PROVIDE(__prg_rom_size = 256);
PROVIDE(__prg_rom_size = 512);

OUTPUT_FORMAT {
INCLUDE ines-header.ld
Expand All @@ -108,5 +172,23 @@ OUTPUT_FORMAT {
FULL(prg_rom_13) FULL(reset, 0, LENGTH(prg_rom_13) ? LENGTH(reset) : 0)
FULL(prg_rom_14) FULL(reset, 0, LENGTH(prg_rom_14) ? LENGTH(reset) : 0)
FULL(prg_rom_fixed) FULL(reset_fixed)

FULL(prg_rom_16) FULL(reset, 0, LENGTH(prg_rom_16) ? LENGTH(reset) : 0)
FULL(prg_rom_17) FULL(reset, 0, LENGTH(prg_rom_17) ? LENGTH(reset) : 0)
FULL(prg_rom_18) FULL(reset, 0, LENGTH(prg_rom_18) ? LENGTH(reset) : 0)
FULL(prg_rom_19) FULL(reset, 0, LENGTH(prg_rom_19) ? LENGTH(reset) : 0)
FULL(prg_rom_20) FULL(reset, 0, LENGTH(prg_rom_20) ? LENGTH(reset) : 0)
FULL(prg_rom_21) FULL(reset, 0, LENGTH(prg_rom_21) ? LENGTH(reset) : 0)
FULL(prg_rom_22) FULL(reset, 0, LENGTH(prg_rom_22) ? LENGTH(reset) : 0)
FULL(prg_rom_23) FULL(reset, 0, LENGTH(prg_rom_23) ? LENGTH(reset) : 0)
FULL(prg_rom_24) FULL(reset, 0, LENGTH(prg_rom_24) ? LENGTH(reset) : 0)
FULL(prg_rom_25) FULL(reset, 0, LENGTH(prg_rom_25) ? LENGTH(reset) : 0)
FULL(prg_rom_26) FULL(reset, 0, LENGTH(prg_rom_26) ? LENGTH(reset) : 0)
FULL(prg_rom_27) FULL(reset, 0, LENGTH(prg_rom_27) ? LENGTH(reset) : 0)
FULL(prg_rom_28) FULL(reset, 0, LENGTH(prg_rom_28) ? LENGTH(reset) : 0)
FULL(prg_rom_29) FULL(reset, 0, LENGTH(prg_rom_29) ? LENGTH(reset) : 0)
FULL(prg_rom_30) FULL(reset, 0, LENGTH(prg_rom_30) ? LENGTH(reset) : 0)
FULL(prg_rom_fixed) FULL(reset_fixed)

FULL(chr_rom)
}