Saturn builds

cmake/targets/saturn.cmake

@@ -85,22 +85,100 @@ target_link_directories(${DUSK_LIBRARY_TARGET_NAME} PRIVATE
 )
 
 target_link_libraries(${DUSK_LIBRARY_TARGET_NAME} PRIVATE
+  # --start-group/--end-group allow circular archive references
+  # (e.g. libyaul allocator symbols referenced by libzip / yyjson objects).
+  -Wl,--start-group
   "${_YAUL_SYSROOT}/lib/libyaul.a"
   "${_YAUL_SYSROOT}/lib/libzip.a"
   "${_YAUL_SYSROOT}/lib/libz.a"
-  m
+  # GCC soft-float / soft-divide runtime (SH-2 has no FPU or hw divider).
+  # -lgcc is resolved by the compiler driver even with -nodefaultlibs.
+  -lgcc
+  -Wl,--end-group
 )
 
+# Yaul linker script (Saturn SH-2 memory map) and startup objects.
+# Startup objects must precede all other objects so use target_link_options
+# (those flags appear before the object-file list in cmake's link command).
+target_link_options(${DUSK_BINARY_TARGET_NAME} PRIVATE
+  "-T${_YAUL_SYSROOT}/lib/ldscripts/yaul.x"
+  "${_YAUL_SYSROOT}/lib/crt0.o"
+  "${_YAUL_SYSROOT}/lib/init.o"
+  # Provide SH-2 stack top addresses required by crt0.o/cpu_dual_entries.o.
+  # RAM region: 0x06004000 .. 0x06100000 (~1 MB).
+  # Master stack grows down from the very top; slave CPU gets 4 KB below.
+  "-Wl,--defsym=___master_stack=0x06100000"
+  "-Wl,--defsym=___slave_stack=0x060FF000"
+)
+
+
 # ---------------------------------------------------------------------------
-# Post-build: ELF → binary image
-# sh2eb-elf-objcopy converts the ELF to a flat binary that IP.BIN loads
-# into Saturn Work RAM.
+# Post-build: ELF → binary → Saturn disc image (ISO + CUE)
 # ---------------------------------------------------------------------------
-set(DUSK_SAT_BIN "${CMAKE_BINARY_DIR}/Dusk.bin")
+set(DUSK_SAT_BIN       "${CMAKE_BINARY_DIR}/Dusk.bin")
+set(DUSK_SAT_IP_BIN    "${CMAKE_BINARY_DIR}/IP.BIN")
+set(DUSK_SAT_CD_DIR    "${CMAKE_BINARY_DIR}/cd")
+set(DUSK_SAT_AUDIO_DIR "${CMAKE_BINARY_DIR}/audio-tracks")
+set(DUSK_SAT_ISO       "${CMAKE_BINARY_DIR}/Dusk.iso")
+set(DUSK_SAT_CUE       "${CMAKE_BINARY_DIR}/Dusk.cue")
+
+# Step 1: ELF → flat binary (loaded into Work RAM by IP.BIN)
 add_custom_command(TARGET ${DUSK_BINARY_TARGET_NAME} POST_BUILD
   COMMAND "${_YAUL_BIN}/sh2eb-elf-objcopy"
           -O binary
           "$<TARGET_FILE:${DUSK_BINARY_TARGET_NAME}>"
           "${DUSK_SAT_BIN}"
-  COMMENT "Converting ${DUSK_BINARY_TARGET_NAME} ELF → ${DUSK_SAT_BIN}"
+  COMMENT "Converting ELF → ${DUSK_SAT_BIN}"
+)
+
+# Step 2: flat binary → IP.BIN (boot header with region security blobs)
+# make-ip writes IP.BIN into dirname(arg1), so it lands at ${CMAKE_BINARY_DIR}/IP.BIN.
+# Pass -1 for 1st-read-size so make-ip uses the actual file size.
+add_custom_command(TARGET ${DUSK_BINARY_TARGET_NAME} POST_BUILD
+  COMMAND ${CMAKE_COMMAND} -E env
+    "YAUL_INSTALL_ROOT=${YAUL_INSTALL_ROOT}"
+    "YAUL_ARCH_SH_PREFIX=sh2eb-elf"
+    "${_YAUL_BIN}/make-ip"
+      "${DUSK_SAT_BIN}"
+      "V1.000"
+      "20260101"
+      "JTUE"
+      "J"
+      "DUSK"
+      "0x06100000"
+      "0x060FF000"
+      "0x06004000"
+      "-1"
+  COMMENT "Generating IP.BIN"
+)
+
+# Step 3: build CD filesystem tree and create ISO 9660 image
+add_custom_command(TARGET ${DUSK_BINARY_TARGET_NAME} POST_BUILD
+  COMMAND ${CMAKE_COMMAND} -E make_directory "${DUSK_SAT_CD_DIR}"
+  COMMAND ${CMAKE_COMMAND} -E make_directory "${DUSK_SAT_AUDIO_DIR}"
+  COMMAND ${CMAKE_COMMAND} -E copy "${DUSK_SAT_BIN}" "${DUSK_SAT_CD_DIR}/A.BIN"
+  # ISO 9660 requires these auxiliary text files
+  COMMAND ${CMAKE_COMMAND} -E touch "${DUSK_SAT_CD_DIR}/ABS.TXT"
+  COMMAND ${CMAKE_COMMAND} -E touch "${DUSK_SAT_CD_DIR}/BIB.TXT"
+  COMMAND ${CMAKE_COMMAND} -E touch "${DUSK_SAT_CD_DIR}/CPY.TXT"
+  COMMAND ${CMAKE_COMMAND} -E env
+    "YAUL_INSTALL_ROOT=${YAUL_INSTALL_ROOT}"
+    "MAKE_ISO_XORRISOFS=/usr/bin/xorrisofs"
+    "${_YAUL_BIN}/make-iso"
+      "${DUSK_SAT_CD_DIR}"
+      "${DUSK_SAT_IP_BIN}"
+      "${CMAKE_BINARY_DIR}"
+      "Dusk"
+  COMMENT "Generating ${DUSK_SAT_ISO}"
+)
+
+# Step 4: ISO → CUE sheet  (rename .iso → .bin for a classic BIN/CUE pair
+# if desired; emulators accept .iso+.cue as-is)
+add_custom_command(TARGET ${DUSK_BINARY_TARGET_NAME} POST_BUILD
+  COMMAND ${CMAKE_COMMAND} -E env
+    "YAUL_INSTALL_ROOT=${YAUL_INSTALL_ROOT}"
+    "${_YAUL_BIN}/make-cue"
+      "${DUSK_SAT_AUDIO_DIR}"
+      "${DUSK_SAT_ISO}"
+  COMMENT "Generating ${DUSK_SAT_CUE}"
 )

cmake/toolchains/saturn.cmake

@@ -48,13 +48,16 @@ set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
 
-# SH-2 core flags: big-endian (-mb), SH-2 ISA (-m2), no FPU
-set(_SAT_C_FLAGS "-m2 -mb -fno-builtin -fomit-frame-pointer")
+# SH-2 core flags: big-endian (-mb), SH-2 ISA (-m2), no FPU.
+# -ffunction-sections/-fdata-sections enable --gc-sections to eliminate
+# unreachable code at the function level (e.g. yyjson FILE* API paths).
+set(_SAT_C_FLAGS "-m2 -mb -fno-builtin -fomit-frame-pointer -ffunction-sections -fdata-sections -Os")
 set(CMAKE_C_FLAGS_INIT   "${_SAT_C_FLAGS}")
 
-# Yaul installs yaul.specs to ${YAUL_INSTALL_ROOT}/sh2eb-elf/lib/ and
-# ldscripts/yaul.x to ${YAUL_INSTALL_ROOT}/sh2eb-elf/lib/ldscripts/.
-# GCC searches ${prefix}/${target}/lib/ for specs, so -specs=yaul.specs works
-# without an absolute path once the SDK is installed.
+# Linker flags: gc-sections, no startup/default libs (Yaul provides crt0/init;
+# we supply all needed libraries explicitly).  -nodefaultlibs prevents cmake/gcc
+# from injecting -lc (which does not exist in the Yaul sysroot).
+# --start-group/--end-group are placed in target_link_libraries in
+# targets/saturn.cmake so they actually wrap the archive list.
 set(CMAKE_EXE_LINKER_FLAGS_INIT
-  "-specs=yaul.specs -Wl,--gc-sections -nostartfiles -Wl,--start-group -Wl,--end-group")
+  "-Wl,--gc-sections -nostartfiles -nodefaultlibs")