reorganize, add sym_lookup

Makefile

@@ -8,8 +8,10 @@ ISO_NAME=os_image.iso
 CC=cc
 LD=ld
 
-CFLAGS=-std=c2x -ffreestanding -fno-stack-protector -g -Wall -Wextra -pedantic -lgcc -isystem $(INCLUDE_DIR)
-CFLAGS+= -DPAGE_SIZE=4096
+CFLAGS+=-std=c2x -ffreestanding -fno-stack-protector -g -Wall -Wextra -pedantic -lgcc -isystem $(INCLUDE_DIR)
+CFLAGS+=-DPAGE_SIZE=4096
+
+LDFLAGS+=-nmagic -T arch/amd64/linker.ld
 
 C_SRC=$(shell find $(SRC_DIR) -type f -name "*.c")
 C_OBJ=$(patsubst %.c,$(BUILD_DIR)/%.o,$(C_SRC))
@@ -37,12 +39,12 @@ $(C_OBJ): $(BUILD_DIR)/%.o : %.c
 
 $(BUILD_DIR)/$(K_BIN_NAME): $(SRC_DIR)/arch/amd64/linker.ld $(A_OBJ) $(C_OBJ) $(H_SRC) $(H_INCLUDE)
 	@mkdir -p $(@D)
-	$(LD) -nmagic -o $(BUILD_DIR)/$(K_BIN_NAME) -T $(SRC_DIR)/arch/amd64/linker.ld $(A_OBJ) $(C_OBJ)
+	$(LD) $(LDFLAGS) -o $(BUILD_DIR)/$(K_BIN_NAME) $(A_OBJ) $(C_OBJ)
 
 $(BUILD_DIR)/$(ISO_NAME): $(BUILD_DIR)/$(K_BIN_NAME) grub.cfg
 	@mkdir -p $(@D)
 	@mkdir -p $(BUILD_DIR)/iso/boot/grub
-	cp grub.cfg $(BUILD_DIR)/iso/boot/grub
+	cp arch/amd64/grub.cfg $(BUILD_DIR)/iso/boot/grub
 	cp $(BUILD_DIR)/$(K_BIN_NAME) $(BUILD_DIR)/iso/boot
 	grub-mkrescue -o $(BUILD_DIR)/$(ISO_NAME) $(BUILD_DIR)/iso
 

arch/amd64/linker.ld

@@ -0,0 +1,38 @@
+ENTRY(start)
+
+SECTIONS {
+    . = 1M;
+    
+    kernel_start = .;
+
+    .boot BLOCK(4K) : ALIGN(4K)
+    {
+        *(.multiboot)
+    }
+
+    .rodata BLOCK(4K) : ALIGN(4K)
+    {
+        *(.rodata)
+    }
+
+    .data BLOCK(4K) : ALIGN(4K)
+    {
+        *(.data)
+    }
+
+    text_start = .;
+
+    .text BLOCK(4K) : ALIGN(4K)
+    {
+        *(.text)
+    }
+
+    text_end = .;
+
+    .bss BLOCK(4K) : ALIGN(4K)
+    {
+        *(.bss)
+    }
+
+    kernel_end = .;
+}

arch/amd64/sym_lookup.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+
+import subprocess
+import bisect
+import sys
+import dataclasses
+
+@dataclasses.dataclass
+class Symbol:
+	addr: int
+	size: int
+	ty: str
+	scope: str
+	name: str
+
+readelf = subprocess.run(
+	["readelf", "-s", "build/kernel.bin"], 
+	capture_output=True, 
+	encoding="UTF-8"
+)
+
+symbols = []
+
+text_start = None
+text_end = None
+
+for line in readelf.stdout.split("\n")[3:-1]:
+	parts = list(line.split());
+	sym = Symbol(
+		addr=int(parts[1], 16),
+		size=int(parts[2]),
+		ty=parts[3],
+		scope=parts[4],
+		name=parts[7] if len(parts) >= 8 else "",
+	)
+	symbols.append(sym)
+	if sym.name == "text_start":
+		text_start = sym.addr
+	if sym.name == "text_end":
+		text_end = sym.addr
+
+symbols.sort(key=lambda s: s.addr)
+
+def find_sym(addr):
+	try:
+		if addr.startswith("0x") or addr.startswith("0X"):
+			addr = int(arg[2:], 16)
+		else:
+			addr = int(arg, 10)
+	except:
+		print(f"Invalid address: {addr}")
+		return
+
+	print(f"Address 0x{addr:016X}:")
+	idx = bisect.bisect_right(symbols, addr, key=lambda s: s.addr)
+	for i in range(idx-1, 0, -1):
+		sym = symbols[i]
+		if sym.addr < text_start:
+			break
+		if sym.addr > text_end:
+			break
+		print(f"\t{sym.name:<20} [0x{sym.addr:016X} : 0x{sym.size:04X}] {sym.ty:<7} {sym.scope:<7}")
+		if sym.ty == "FUNC":
+			return
+	print("\t<end of text>")
+
+for arg in sys.argv[1:]:
+	find_sym(arg.strip())

include/backtrace.h

@@ -6,13 +6,9 @@
 // in order from top to bottom. returns the number filled (at most len)
 size_t backtrace(void **dst, size_t len);
 
-
 // same as backtrace but with specified instruction and base pointer
 size_t backtrace_ex(void **dst, size_t len, void* ip, void *bp);
 
-// TODO symbols
-//size_t backtrace_symbols(char *const *dst, size_t len);
-
 // Log a backtrace
 void log_backtrace();
 

src/arch/amd64/linker.ld

@@ -1,38 +0,0 @@
-ENTRY(start)
-
-PHDRS {
-	loadable PT_LOAD FLAGS(7) ;
-}
-
-SECTIONS {
-	. = 1M;
-
-	kernel_start = .;
-
-	.boot BLOCK(4K) : ALIGN(4K)
-	{
-	    *(.multiboot)
-	}
-
-	.rodata BLOCK(4K) : ALIGN(4K)
-	{
-	    *(.rodata)
-	}
-
-	.text BLOCK(4K) : ALIGN(4K)
-	{
-	    *(.text)
-	}
-
-	.bss BLOCK(4K) : ALIGN(4K)
-	{
-	    *(.bss)
-	}
-
-	.symtab : {
-	    symtab = .;
-	    *(.symtab)
-	} :loadable
-
-	kernel_end = .;
-}