Reorganized for running out of handler space

README.md

@@ -84,10 +84,14 @@ breaking changes.**
   buffers, **saving some DRAM traffic** (maybe around 100 us per frame). The
   bits used for this are ignored by HLE.
 - Segment addresses are now resolved relative to other segments (feature by
-  Tharo). This enables a strategy for skipping repeated material DLs: call
+  Tharo). This enables a strategy for **skipping repeated material DLs**: call
   a segment to run the material, remap the segment in the material to a
   display list that immediately returns, and so if the material is called again
   it won't run.
+- New `SPMemset` command fills a specified RDRAM region with a repeated 16-bit
+  value. This can be used for clearing the Z buffer or filling the framebuffer
+  or the letterbox with a solid color **faster than the RDP can in fill mode**.
+  Practical performance may vary due to scheduling constraints.
 
 ### Miscellaneous
 

gbi.h

@@ -2388,6 +2388,9 @@ _DW({                                               \
 /**
  * Use RSP DMAs to set a region of memory to a repeated 16-bit value. This can
  * clear the color framebuffer or Z-buffer faster than the RDP can in fill mode.
+ * SPMemset overwrites the DMEM vertex buffer, so vertices loaded before this
+ * command cannot be used after it (though this would not normally be done).
+ * 
  * dram: Segmented or physical start address. Must be aligned to 16 bytes.
  * value: 16-bit value to fill the memory with. e.g. 0 for color, 0xFFFC for Z.
  * size: Size in bytes to fill, must be nonzero and a multiple of 16 bytes.

rsp/rsp_defs.inc

@@ -14,18 +14,18 @@ YDF_OFFSET_TASKDATAPTR  equ 0x10
 YDF_OFFSET_UCODE        equ 0x14
 
 // OSTask data member offsets
-OSTask_type             equ 0x0000
-OSTask_flags            equ 0x0004 // see note below
-OSTask_ucode_boot       equ 0x0008
-OSTask_ucode_boot_size  equ 0x000C
+OSTask_type             equ 0x0000 //                      EX3: fourthQWMVP ^
+OSTask_flags            equ 0x0004 // see note below                        |
+OSTask_ucode_boot       equ 0x0008 //                                       |
+OSTask_ucode_boot_size  equ 0x000C //                                       v
 OSTask_ucode            equ 0x0010 // used in F3D, S2D, and boot
-OSTask_ucode_size       equ 0x0014
-OSTask_ucode_data       equ 0x0018 // used in boot only
-OSTask_ucode_data_size  equ 0x001C // used in boot only
+OSTask_ucode_size       equ 0x0014 //                      EX3: startCounterTime
+OSTask_ucode_data       equ 0x0018 // used in boot only.   EX3: xfrmLookatDirs ^
+OSTask_ucode_data_size  equ 0x001C // used in boot only                        v
 OSTask_dram_stack       equ 0x0020 // used in F3D and S2D at first startup
 OSTask_dram_stack_size  equ 0x0024
 OSTask_output_buff      equ 0x0028 // used in F3D and S2D
-OSTask_output_buff_size equ 0x002C // actually end pointer; used in F3D and S2D
+OSTask_output_buff_size equ 0x002C // used in F3D and S2D; actually end pointer not size
 OSTask_data_ptr         equ 0x0030 // used in F3D and S2D
 OSTask_data_size        equ 0x0034
 OSTask_yield_data_ptr   equ 0x0038 // used in F3D and S2D