Replace `spicy` with linker scripts

4 files changed, 86 insertions, 22 deletions

diff --git a/Makefile b/Makefile
index 5250c36..f402bd2 100644
--- a/Makefile
+++ b/Makefile
@@ -12,11 +12,15 @@ LIBULTRA     := $(LIBULTRA_DIR)/usr/lib/libgultra.a
 # Source code location and files to watch for changes.
 SRC_DIR     := src
 BUILD_DIR   := build
-SRC_MAIN    := $(SRC_DIR)/main.c
+SRC_MAIN    := $(SRC_DIR)/main.c $(SRC_DIR)/entry.s
+SRC_LN      := $(SRC_DIR)/linker.ld
 SRC_OBJ     :=
 OBJECTS     := $(patsubst $(SRC_DIR)/%.c, $(BUILD_DIR)/%.o, $(SRC_OBJ))
-
-WATCH_SRC   := $(shell find $(SRC_DIR) -name "*.c" -or -name "*.s" -or -name "*.h")
+WATCH_SRC   := $(shell find $(SRC_DIR) \
+                           -name "*.c" -or \
+                           -name "*.s" -or \
+                           -name "*.h" -or \
+                           -name "**.ld")
 INC_DIRS    := $(shell find $(SRC_DIR) -type d)
 INC_DIRS    += $(LIBULTRA_INC)
 INC_FLAGS   := $(addprefix -I,$(INC_DIRS))
@@ -31,8 +35,8 @@ CC       := $(SDK_BIN)/mips32-elf-gcc
 LD       := $(SDK_BIN)/mips32-elf-ld
 AS       := $(SDK_BIN)/mips32-elf-as
 OBJDUMP  := $(SDK_BIN)/mips32-elf-objdump
+OBJCOPY  := $(SDK_BIN)/mips32-elf-objcopy
 # TODO: Replace with internal tools to avoid dependencies.
-SPICY    := $(SDK_BIN)/spicy
 MAKEMASK := $(SDK_BIN)/makemask
 
 # Compiler and linker configuration.
@@ -40,8 +44,8 @@ CFLAGS         := -Wall -Wextra -pedantic
 CFLAGS         += -mabi=32 -mfix4300
 CFLAGS         += -ffreestanding -G 0
 CFLAGS         += $(INC_FLAGS)
-CFLAGS         += -DF3DEX_GBI_2 -nostdlib -r
-LDFLAGS        := -nostdlib -r
+CFLAGS         += -DF3DEX_GBI_2
+LDFLAGS        := -nostdlib
 LDLIBS         := $(LIBULTRA) $(SDK_BASE)/lib/gcc/mips32-elf/13.0.0/libgcc.a
 RELEASE_CFLAGS := -O2 -DNDEBUG -D_FINALROM
 DEBUG_CFLAGS   := -O0 -DDEBUG -D_FINALROM
@@ -59,15 +63,10 @@ endif
 main: $(BIN)
 
 $(ELF): $(SRC_MAIN) $(WATCH_SRC) | $(BUILD_DIR)
-        $(CC) $(CFLAGS) $(LDFLAGS) -o $(ELF) $(SRC_MAIN) $(LDLIBS)
+        $(CC) $(CFLAGS) $(LDFLAGS) -o $(ELF) -T $(SRC_LN) $(SRC_MAIN) $(LDLIBS)
 
 $(BIN): $(ELF) $(OBJECTS) $(WATCH_SRC) | $(BUILD_DIR)
-        $(SPICY) -r $@ $(SRC_DIR)/spec \
-                --as_command="$(SDK_BIN)/mips32-elf-as" \
-                --cpp_command="$(SDK_BIN)/mips32-elf-gcc" \
-                --ld_command="$(SDK_BIN)/mips32-elf-ld" \
-                --objcopy_command="$(SDK_BIN)/mips32-elf-objcopy"
-        rm a.out
+        $(OBJCOPY) -O binary $< $@
         $(MAKEMASK) $(BIN)
 
 # Test the output .n64 in an emulator.
@@ -86,3 +85,7 @@ $(BUILD_DIR):
 # Inference rules for C files.
 $(BUILD_DIR)/%.o: $(SRC_DIR)/%.c | $(BUILD_DIR)
         $(CC) $(CFLAGS) $< -o $@
+
+# Inference rules for assembly files.
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.s | $(BUILD_DIR)
+        $(AS) $(AFLAGS) -o $@ -c $<
diff --git a/src/entry.s b/src/entry.s
new file mode 100644
index 0000000..3ff60ba
--- /dev/null
+++ b/src/entry.s
@@ -0,0 +1,16 @@
+# Entry point for the ROM image.
+        .section .text.entry
+        .global _start
+_start:
+
+        # Set up the stack
+        la      $sp, _boot_stack
+
+        # Zero BSS.
+        la      $a0, _bss_start
+        la      $a1, _bss_end
+        subu    $a1, $a1, $a0
+        jal     bzero
+
+        # Jump to C entry point.
+        j       boot
diff --git a/src/linker.ld b/src/linker.ld
new file mode 100644
index 0000000..91bd28a
--- /dev/null
+++ b/src/linker.ld
@@ -0,0 +1,50 @@
+ENTRY(_start)
+
+STACK_SIZE = 8K;
+
+MEMORY {
+    rom (R) : ORIGIN = 0, LENGTH = 64M
+    ram (RWX) : ORIGIN = 0x80000400, LENGTH = 4M - 0x400
+}
+
+SECTIONS {
+    .header : {
+        LONG(0x80371240)
+        LONG(0x0000000f)
+        LONG(0x80000400)
+        LONG(0x0000144c)
+        . = 0x1000;
+    } >rom
+
+    .text : {
+        _text_start = .;
+        *(.text.entry)
+        *(.text .text.*)
+        *(.rodata .rodata.*)
+        *(.data .data.*)
+        _text_end = .;
+    } >ram AT>rom
+
+    .bss (NOLOAD) : ALIGN(16) {
+        _bss_start = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        *(.scommon .scommon.*)
+        _bss_end = .;
+    } >ram
+
+    .stack (NOLOAD) : ALIGN(16) {
+        . += STACK_SIZE;
+        . = ALIGN(8);
+        _boot_stack = .;
+        _main_thread_stack = .;
+
+        . += STACK_SIZE;
+        . = ALIGN(8);
+        _idle_thread_stack = .;
+    } >ram
+
+    /DISCARD/ : {
+        *(*)
+    }
+}
diff --git a/src/main.c b/src/main.c
index eca114f..53612d6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,19 +2,14 @@
 
 #include "types.h"
 
-// Get a pointer to the start (top) of a stack.
-#define STACK_START(stack) ((stack) + sizeof((stack)))
-
 //
 // Threads and stacks.
 //
 
-#define STACK_SIZE 8 * 1024
 static OSThread idle_thread;
 static OSThread main_thread;
-static u8 idle_thread_stack[STACK_SIZE]  __attribute__((aligned(8)));
-static u8 main_thread_stack[STACK_SIZE]  __attribute__((aligned(8)));
-u64 boot_stack[STACK_SIZE / sizeof(u64)] __attribute__((aligned(8)));
+extern u8 _idle_thread_stack[];
+extern u8 _main_thread_stack[];
 
 //
 // Message buffers and queues.
@@ -268,7 +263,7 @@ idle_proc(void *arg) {
     osCreatePiManager((OSPri)OS_PRIORITY_PIMGR, &pi_msg_queue, pi_msg, NUM_PI_MSGS);
 
     // Create main thread.
-    osCreateThread(&main_thread, 3, main_proc, NULL, STACK_START(main_thread_stack), 10);
+    osCreateThread(&main_thread, 3, main_proc, NULL, _main_thread_stack, 10);
     osStartThread(&main_thread);
 
     // Become the idle thread.
@@ -281,6 +276,6 @@ void
 boot(void) {
     osInitialize();
     rom_handle = osCartRomInit();
-    osCreateThread(&idle_thread, 1, idle_proc, NULL, STACK_START(idle_thread_stack), 10);
+    osCreateThread(&idle_thread, 1, idle_proc, NULL, _idle_thread_stack, 10);
     osStartThread(&idle_thread);
 }