From 8fcf0dedac588777df63e1fcbbcb3cc3fd2814d1 Mon Sep 17 00:00:00 2001
From: Nicolas <Nicolas@nonan.net>
Date: Mon, 2 Mar 2026 21:28:05 +0100
Subject: [PATCH] patch type added: PATCH_OBJECT_ARM32_ABS_THM (for
 R_ARM_THM_MOVW_ABS_NC and R_ARM_THM_MOVT_ABS)

---
 src/copapy/_binwrite.py |  1 +
 src/coparun/runmem.c    | 40 ++++++++++++++++++++++++++++++++++++++--
 src/coparun/runmem.h    |  1 +
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/src/copapy/_binwrite.py b/src/copapy/_binwrite.py
index e1d7c90..1af2ee3 100644
--- a/src/copapy/_binwrite.py
+++ b/src/copapy/_binwrite.py
@@ -13,6 +13,7 @@ Command = Enum('Command', [('ALLOCATE_DATA', 1), ('COPY_DATA', 2),
                            ('PATCH_OBJECT_ABS', 0x2002),
                            ('PATCH_OBJECT_REL', 0x2003),
                            ('PATCH_OBJECT_ARM32_ABS', 0x2004),
+                           ('PATCH_OBJECT_ARM32_ABS_THM', 0x2006),
                            ('ENTRY_POINT', 7),
                            ('RUN_PROG', 64), ('READ_DATA', 65),
                            ('END_COM', 256), ('FREE_MEMORY', 257), ('DUMP_CODE', 258)])
diff --git a/src/coparun/runmem.c b/src/coparun/runmem.c
index e5180e5..b905e97 100644
--- a/src/coparun/runmem.c
+++ b/src/coparun/runmem.c
@@ -50,6 +50,32 @@ void patch_arm32_abs(uint8_t *patch_addr, uint32_t imm16)
     *((uint32_t *)patch_addr) = instr;
 }
 
+void patch_arm_thm_abs(uint8_t *patch_addr, uint32_t imm16)
+{
+    // Thumb MOVW (T3) / MOVT (T1) encoding
+    
+    uint16_t *instr16 = (uint16_t *)patch_addr;
+    uint16_t first_half = instr16[0];
+    uint16_t second_half = instr16[1];
+
+    // Extract fields from imm16
+    uint32_t imm4 = (imm16 >> 12) & 0xF;
+    uint32_t i    = (imm16 >> 11) & 0x1;
+    uint32_t imm3 = (imm16 >> 8) & 0x7;
+    uint32_t imm8 = imm16 & 0xFF;
+
+    // Clear bits
+    first_half &= (uint16_t)(~(0x000F | (1 << 10)));
+    second_half &= (uint16_t)(~(0x00FF | (0x7 << 12)));
+
+    // Set new fields
+    first_half |= (uint16_t)((imm4 << 0) | (i << 10));
+    second_half |= (uint16_t)(imm8 | (imm3 << 12));
+
+    instr16[0] = first_half;
+    instr16[1] = second_half;
+}
+
 void patch_arm_thm_jump24(uint8_t *patch_addr, int32_t imm24)
 {
     // Read the 32-bit instruction (two halfwords)
@@ -77,8 +103,8 @@ void patch_arm_thm_jump24(uint8_t *patch_addr, int32_t imm24)
     second_half &= 0xD000;           // Keep upper 5 bits
 
     // Set new imm fields
-    first_half  |= (S << 10) | imm10;
-    second_half |= (J1 << 13) | (J2 << 11) | imm11;
+    first_half  |= (uint16_t)((S << 10) | imm10);
+    second_half |= (uint16_t)((J1 << 13) | (J2 << 11) | imm11);
 
     // Write back
     instr16[0] = first_half;
@@ -225,6 +251,16 @@ int parse_commands(runmem_t *context, uint8_t *bytes) {
                 patch_arm_thm_jump24(context->executable_memory + offs, value);
                 break;
 
+            case PATCH_OBJECT_ARM32_ABS_THM:
+                offs = *(uint32_t*)bytes; bytes += 4;
+                patch_mask = *(uint32_t*)bytes; bytes += 4;
+                patch_scale = *(int32_t*)bytes; bytes += 4;
+                value = *(int32_t*)bytes; bytes += 4;
+                LOG("PATCH_OBJECT_ARM32_ABS_THM patch_offs=%i patch_mask=%#08x scale=%i value=%i imm16=%#04x\n",
+                    offs, patch_mask, patch_scale, value, (uint32_t)((uintptr_t)(context->data_memory + value) & patch_mask) / (uint32_t)patch_scale);
+                patch_arm_thm_abs(context->executable_memory + offs, (uint32_t)((uintptr_t)(context->data_memory + value) & patch_mask) / (uint32_t)patch_scale);
+                break;
+
             case ENTRY_POINT:
                 rel_entr_point = *(uint32_t*)bytes; bytes += 4;
                 context->entr_point = (entry_point_t)(context->executable_memory + rel_entr_point);
diff --git a/src/coparun/runmem.h b/src/coparun/runmem.h
index 371f2f3..17da047 100644
--- a/src/coparun/runmem.h
+++ b/src/coparun/runmem.h
@@ -26,6 +26,7 @@
 #define PATCH_OBJECT_ABS  0x2002
 #define PATCH_OBJECT_REL  0x2003
 #define PATCH_OBJECT_ARM32_ABS 0x2004
+#define PATCH_OBJECT_ARM32_ABS_THM 0x2006
 #define ENTRY_POINT       7
 #define RUN_PROG         64
 #define READ_DATA        65