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Merge pull request #8059 from JosJuice/casper-dcache-hack-pal

Port Casper's Scare School: Spooky Sports Day dcache hack to PAL
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leoetlino committed May 1, 2019
2 parents 37c85b3 + 0ac642a commit d9999f406bb42ab3b46b393bdb2e9a088020e5bb
Showing with 28 additions and 2 deletions.
  1. +2 −2 Data/Sys/GameSettings/RX4E4Z.ini
  2. +26 −0 Data/Sys/GameSettings/RX4PMT.ini
@@ -1,4 +1,4 @@
# Casper's Scare School: Spooky Sports Day (RX4E4Z)
# RX4E4Z - Casper's Scare School: Spooky Sports Day

[OnFrame]
# Work around a dcache issue by preventing the game from doing something pointless.
@@ -17,7 +17,7 @@
# .text:800D2E6C mr r5, read_length # length
# .text:800D2E70 mr r6, read_offset # offset
# .text:800D2E74 addi r3, this, file.file_info # file_info
# .text:800D2E78 addi r4, r4, dvd_read_buf@l # addr
# .text:800D2E78 subi r4, r4, dvd_read_buf@l # addr
# .text:800D2E7C addi r7, r7, game_dvd_read_callback@l # callback
# .text:800D2E80 li r8, 2 # unknown
# .text:800D2E84 bl DVDReadAsync
@@ -0,0 +1,26 @@
# RX4PMT - Casper's Scare School: Spooky Sports Day

[OnFrame]
# Work around a dcache issue by preventing the game from doing something pointless.
#
# The game's DVD read function writes 0x87654321 to the entire read buffer and 0x12345678 to the
# last 4 bytes. It then calls DVDReadAsync() and without waiting for the read to complete at all,
# it checks if the last 4 bytes are still 0x12345678. If they are, then the game fails.
#
# The check always passes on console because DVDReadAsync() -> issueCommand() calls
# DCInvalidateRange() (dcbi) on the read buffer.
#
# Dolphin cannot emulate this without an extremely significant performance hit.
#
# .text:80164B8C lis r7, game_dvd_read_callback@ha
# .text:80164B90 stw r0, 0(r17) # write 0x12345678 to the end of the buffer
# .text:80164B94 mr r5, read_length # length
# .text:80164B98 mr r6, read_offset # offset
# .text:80164B9C addi r3, this, file.file_info # file_info
# .text:80164BA0 subi r4, r4, dvd_read_buf@l # addr
# .text:80164BA4 addi r7, r7, game_dvd_read_callback@l # callback
# .text:80164BA8 li r8, 2 # unknown
# .text:80164BAC bl DVDReadAsync
#
$Fix file reads (dcache bypass)
0x80164b90:dword:0x60000000

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