From bab24b766025e41d5116f4fd8681c79d3acf2fcc Mon Sep 17 00:00:00 2001
From: Ryan Dwyer <ryandwyer1@gmail.com>
Date: Mon, 22 Nov 2021 20:31:52 +1000
Subject: [PATCH] Disassemble rspboot microcode

---
 Makefile          | 12 ++++++-
 README.md         |  3 +-
 src/rsp/rspboot.s | 89 +++++++++++++++++++++++++++++++++++++++++++++++
 tools/extract     |  1 -
 4 files changed, 102 insertions(+), 3 deletions(-)
 create mode 100644 src/rsp/rspboot.s

diff --git a/Makefile b/Makefile
index dc9bdec72..39b10c0ae 100644
--- a/Makefile
+++ b/Makefile
@@ -496,8 +496,18 @@ $(B_DIR)/assets/accessingpakZ.o: $(B_DIR)/assets/accessingpakZ
 $(B_DIR)/assets/copyrightZ.o: $(B_DIR)/assets/copyrightZ
 	TOOLCHAIN=$(TOOLCHAIN) ROMID=$(ROMID) tools/mkrawobject $< $@
 
-$(B_DIR)/rsp/%.o: $(E_DIR)/rsp/%.bin
+$(B_DIR)/rsp/%.text.bin: src/rsp/%.s
 	@mkdir -p $(dir $@)
+	armips -strequ CODE_FILE $(B_DIR)/rsp/$*.text.bin -strequ DATA_FILE $(B_DIR)/rsp/$*.data.bin $<
+
+$(B_DIR)/rsp/%.data.bin: src/rsp/%.text.bin
+
+# For RSP ucodes which haven't been diassembled yet, copy from extracted
+$(B_DIR)/rsp/%.bin: $(E_DIR)/rsp/%.bin
+	@mkdir -p $(dir $@)
+	cp $< $@
+
+$(B_DIR)/rsp/%.o: $(B_DIR)/rsp/%.bin
 	TOOLCHAIN=$(TOOLCHAIN) ROMID=$(ROMID) tools/mkrawobject $< $@
 
 $(B_DIR)/lib/ultra/libc/llcvt.o: src/lib/ultra/libc/llcvt.c $(ASSETMGR_O_FILES)
diff --git a/README.md b/README.md
index ae1a3ce11..f8ede26a4 100644
--- a/README.md
+++ b/README.md
@@ -11,11 +11,12 @@ See the [Perfect Dark Decompilation Status Page](https://ryandwyer.gitlab.io/pds
 For Arch Linux:
 
 * Install these packages: `binutils fakeroot gcc make python vim`
-* Install from AUR: `mips64-elf-binutils`
+* Install from AUR: `armips mips64-elf-binutils`
 
 For Debian and Ubuntu:
 
 * Install these packages: `binutils-mips-linux-gnu make`
+* Compile and install `armips`
 
 ## ROM Versions
 
diff --git a/src/rsp/rspboot.s b/src/rsp/rspboot.s
new file mode 100644
index 000000000..e7387874f
--- /dev/null
+++ b/src/rsp/rspboot.s
@@ -0,0 +1,89 @@
+.rsp
+
+// OSTask placed at end of DMEM (IMEM_START - sizeof(OSTask))
+.definelabel OSTask_addr, 0xfc0
+
+// OSTask data member offsets
+OSTask_flags           equ 0x04
+OSTask_ucode           equ 0x10
+OSTask_ucode_size      equ 0x14
+OSTask_ucode_data      equ 0x18
+OSTask_ucode_data_size equ 0x1c
+
+OS_TASK_DP_WAIT        equ 0x0002
+
+// RDP Status read flags
+DPC_STATUS_DMA_BUSY    equ 0x0100
+
+.create CODE_FILE, 0x04001000
+
+    j     rdpcheck
+     addi  at, zero, OSTask_addr
+
+ucodeload:
+    lw    v0, OSTask_ucode(at)
+    addi  v1, zero, 0x0f7f
+    addi  a3, zero, 0x1080
+    mtc0  a3, SP_MEM_ADDR
+    mtc0  v0, SP_DRAM_ADDR
+    mtc0  v1, SP_RD_LEN
+
+ucodeloadloop:
+    mfc0  a0, SP_DMA_BUSY
+    bne   a0, zero, ucodeloadloop
+     nop
+    jal   checkyield
+     nop
+    jr    a3
+     mtc0  zero, SP_SEMAPHORE
+
+checkyield:
+    mfc0  t0, SP_STATUS
+    andi  t0, t0, 0x0080
+    bne   t0, zero, Yield
+     nop
+    jr    ra
+
+Yield:
+     mtc0  zero, SP_SEMAPHORE
+    ori   t0, zero, 0x5200
+    mtc0  t0, SP_STATUS
+    break
+    nop
+
+rdpcheck:
+    lw    v0, OSTask_flags(at)
+    andi  v0, v0, OS_TASK_DP_WAIT
+    beq   v0, zero, rdpwait
+     nop
+    jal   checkyield
+     nop
+    mfc0  v0, DPC_STATUS
+    andi  v0, v0, DPC_STATUS_DMA_BUSY
+    bgtz  v0, checkyield
+     nop
+
+rdpwait:
+    lw    v0, OSTask_ucode_data(at)
+    lw    v1, OSTask_ucode_data_size(at)
+    addi  v1, v1, -1
+
+DMEMLoad:
+    mfc0  s8, SP_DMA_FULL
+    bne   s8, zero, DMEMLoad
+     nop
+    mtc0  zero, SP_MEM_ADDR
+    mtc0  v0, SP_DRAM_ADDR
+    mtc0  v1, SP_RD_LEN
+
+dmaloop:
+    mfc0  a0, SP_DMA_BUSY
+    bne   a0, zero, dmaloop
+     nop
+    jal   checkyield
+     nop
+    j     ucodeload
+     nop
+    nop
+
+.close // CODE_FILE
diff --git a/tools/extract b/tools/extract
index d1546aa72..c812cec73 100755
--- a/tools/extract
+++ b/tools/extract
@@ -252,7 +252,6 @@ class Extractor:
         self.write_extracted('rsp/' + name, content)
 
     def extract_rsp(self):
-        self.extract_rsp_segment('rspboot.text.bin', 0, 0xd0)
         self.extract_rsp_segment('gsp.text.bin', 0xd0, 0x1420)
         self.extract_rsp_segment('asp.text.bin', 0x14f0, 0x1930)
         self.extract_rsp_segment('gsp.data.bin', -0x1350, 0x800)