Add Whatcookie's delta time patch. Fixes #4.

gibbed · Jun 18, 2020 · 443d7bd · 443d7bd
1 parent 48edf2d
commit 443d7bd
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Showing 9 changed files with 88 additions and 15 deletions.
diff --git a/build.bat b/build.bat
@@ -27,14 +27,15 @@ set "AS_FLAGS=-target ppc64-unknown-unknown -m64 -mllvm --x86-asm-syntax=intel"
 
 "%AS%" %AS_FLAGS%                -c source/debug_menu.S            -o build/debug_menu.o
 "%AS%" %AS_FLAGS%                -c source/debug_menu_localize.S   -o build/debug_menu_localize.o
+"%AS%" %AS_FLAGS%                -c source/delta_time.S            -o build/delta_time.o
 "%AS%" %AS_FLAGS%                -c source/disable_system_cache.S  -o build/disable_system_cache.o
 "%AS%" %AS_FLAGS%                -c source/increase_memory_zones.S -o build/increase_memory_zones.o
 "%AS%" %AS_FLAGS%                -c source/lua_print_to_stdout.S   -o build/lua_print_to_stdout.o
 "%AS%" %AS_FLAGS%                -c source/redirect_fs.S           -o build/redirect_fs.o
 "%AS%" %AS_FLAGS%                -c source/start.S                 -o build/start.o
 "%AS%" %AS_FLAGS% -DMAKE_SYMBOLS -c source/symbols.S               -o build/symbols.o
 
-"%LLVM_PATH%\bin\ld.lld.exe" --script link.x --no-check-sections build/debug_menu.o build/debug_menu_localize.o build/disable_system_cache.o build/increase_memory_zones.o build/lua_print_to_stdout.o build/redirect_fs.o build/start.o build/symbols.o -o bin/debug_patch.elf
+"%LLVM_PATH%\bin\ld.lld.exe" --script link.x --no-check-sections build/debug_menu.o build/debug_menu_localize.o build/delta_time.o build/disable_system_cache.o build/increase_memory_zones.o build/lua_print_to_stdout.o build/redirect_fs.o build/start.o build/symbols.o -o bin/debug_patch.elf
 
 if not defined APPVEYOR (
   tools\bin\PatchElf.exe bin\boot.elf bin\debug_patch.elf bin\debug.elf -v 83681f6110d33442329073b72b8dc88a2f677172 -a --dca=0x01842d48 --dcs=53944 --ocs=0x1832d48

diff --git a/link.x b/link.x
@@ -5,11 +5,12 @@ SECTIONS
   {
     .text0 { build/debug_menu.o(.text) } : code_seg
     .text1 { build/debug_menu_localize.o(.text) } : code_seg
-    .text2 { build/disable_system_cache.o(.text) } : code_seg
-    .text3 { build/increase_memory_zones.o(.text) } : code_seg
-    .text4 { build/lua_print_to_stdout.o(.text) } : code_seg
-    .text5 { build/redirect_fs.o(.text) } : code_seg
-    .text6 { build/symbols.o(.text) } : code_seg
+    .text2 { build/delta_time.o(.text) } : code_seg
+    .text3 { build/disable_system_cache.o(.text) } : code_seg
+    .text4 { build/increase_memory_zones.o(.text) } : code_seg
+    .text5 { build/lua_print_to_stdout.o(.text) } : code_seg
+    .text6 { build/redirect_fs.o(.text) } : code_seg
+    .text7 { build/symbols.o(.text) } : code_seg
   }
 
   . = 0x01842D48;
@@ -20,11 +21,12 @@ SECTIONS
   {
     .data0 { build/debug_menu.o(.data) } : data_seg
     .data1 { build/debug_menu_localize.o(.data) } : data_seg
-    .data2 { build/disable_system_cache.o(.data) } : data_seg
-    .data3 { build/increase_memory_zones.o(.data) } : data_seg
-    .data4 { build/lua_print_to_stdout.o(.data) } : data_seg
-    .data5 { build/redirect_fs.o(.data) } : data_seg
-    .data6 { build/symbols.o(.data) } : data_seg
+    .data2 { build/delta_time.o(.data) } : data_seg
+    .data3 { build/disable_system_cache.o(.data) } : data_seg
+    .data4 { build/increase_memory_zones.o(.data) } : data_seg
+    .data5 { build/lua_print_to_stdout.o(.data) } : data_seg
+    .data6 { build/redirect_fs.o(.data) } : data_seg
+    .data7 { build/symbols.o(.data) } : data_seg
   }
 
   .patch_list : { *(.patch_list) } : data_seg

diff --git a/source/delta_time.S b/source/delta_time.S
@@ -0,0 +1,63 @@
+#include "helpers.inc.S"
+#include "options.inc.S"
+#include "symbols.S"
+
+.set patch_section_index, 2
+
+#ifdef DELTA_TIME
+
+patch_text_start call_delta_time
+  bl my_delta_time
+  nop
+  nop
+patch_text_end call_delta_time
+
+patch_text_start initialize_flip_mode
+  stb %r0, 0x6ED(%r31)
+patch_text_end initialize_flip_mode
+
+cave_start my_delta_time
+  # get mftb
+  mftb %r21                                   // Move from timebase register (clock)
+
+  # get mftb delta
+  lis %r22, my_delta_time_previous@h
+  addi %r22, %r22, my_delta_time_previous@l
+  ld %r20, 0x0(%r22)                          // load previous frames mftb reading
+  std %r21, 0x0(%r22)                         // store this frames mftb reading
+  subf %r19, %r20, %r21                       // subtract previous mftb reading from this mftb frames reading
+
+  # mftb delta to float
+  std %r19, 0x18(%r22)                        // store mftb delta (to be loaded into FPR)
+  lfd %f30, 0x18(%r22)                        // load mftb delta into FPR
+  fcfid %f30, %f30                            // convert integer to double
+  frsp %f30, %f30                             // round to single precision
+
+  # mftb delta to seconds
+  lis %r18, my_delta_time_constants@h
+  addi %r18, %r18, my_delta_time_constants@l
+  lfs %f29, 0x0(%r18)                         // load timebase frequency constant
+  lfs %f28, 0x4(%r18)                         // load maximum timestep size
+  fdivs %f31, %f30, %f29                      // divide timebase delta by timebase frequency
+
+  # check timestep size
+  fcmpu %cr7, %f31, %f28                      // compare current delta time to maximum timestep
+  blt %cr7, _skip_return_maximum_timestep     // don't return the maximum timestep size
+
+_return_maximum_timestep:
+  # set maximum timestep
+  fmr %f31, %f28                              // move maximum timestep to be returned
+
+_skip_return_maximum_timestep:
+  # cleanup
+  xor %r20, %r20, %r20                        // zero r20
+  xor %r19, %r19, %r19                        // zero r19
+  blr
+cave_end my_delta_time
+
+cave_start my_delta_time_constants
+  .float 80000000.0 # timebase frequency (80mhz)
+  .float 0.05000000 # maximum timestep size (50ms or 20FPS)
+cave_end my_delta_time_constants
+
+#endif
diff --git a/source/disable_system_cache.S b/source/disable_system_cache.S
@@ -2,7 +2,7 @@
 #include "options.inc.S"
 #include "symbols.S"
 
-.set patch_section_index, 2
+.set patch_section_index, 3
 
 #ifdef DISABLE_SYSTEM_CACHE
 

diff --git a/source/increase_memory_zones.S b/source/increase_memory_zones.S
@@ -2,7 +2,7 @@
 #include "options.inc.S"
 #include "symbols.S"
 
-.set patch_section_index, 3
+.set patch_section_index, 4
 
 #ifdef INCREASE_MEMORY_ZONES
 

diff --git a/source/lua_print_to_stdout.S b/source/lua_print_to_stdout.S
@@ -2,7 +2,7 @@
 #include "options.inc.S"
 #include "symbols.S"
 
-.set patch_section_index, 4
+.set patch_section_index, 5
 
 #ifdef LUA_PRINT_TO_STDOUT
 

diff --git a/source/options.inc.S b/source/options.inc.S
@@ -18,4 +18,8 @@
 # Make lua's print() output to stdout
 #define LUA_PRINT_TO_STDOUT
 
+# Enable Whatcookie's delta time patch.
+# This is probably BAD(!) on a real PS3.
+#define DELTA_TIME
+
 #endif
diff --git a/source/redirect_fs.S b/source/redirect_fs.S
@@ -1,7 +1,7 @@
 #include "helpers.inc.S"
 #include "options.inc.S"
 
-.set patch_section_index, 5
+.set patch_section_index, 6
 
 #ifdef REDIRECT_FS
 

diff --git a/source/symbols_BLUS30443.S b/source/symbols_BLUS30443.S
@@ -4,9 +4,11 @@
 
 target_text get_debug_menu_root,                  0x00015328
 target_text create_debug_menu,                    0x00015A58
+target_text call_delta_time,                      0x0001B95C
 target_text call_render_debug_menu,               0x0001BB38
 target_text call_create_debug_menu,               0x00020F44
 target_text get_hg_man_instance,                  0x00023878
+target_text initialize_flip_mode,                 0x00025ED8
 target_text allocate_memory_debug_1,              0x0003A1FC
 target_text allocate_memory_debug_2,              0x0003A244
 target_text allocate_memory_debug_3,              0x0003A2B0
@@ -41,4 +43,5 @@ target_rdata title_sce_server_label,              0x016C7CF0
 
 # .data
 
+target_data my_delta_time_previous,               0x01852608  # padding re-used for delta time patch
 target_data lua_print_pointer,                    0x0196E568