From a4dea4148157a94a9143dbbd92fdd88b4358676c Mon Sep 17 00:00:00 2001
From: Alexey Gavrilov <alexey.gavrilov@mail.com>
Date: Sat, 20 Dec 2025 19:39:05 +0700
Subject: Global variables initialization implementation

User implementation of C runtime library objects (`crti.s` and `crtn.s`)
    for initialization (termination functionality are ignored).

Changing files order passed to the linker. Rough order is:
    boot.s crti.o crtbegin.o other-link-objects.o crtend.o crtn.o

Signed-off-by: Alexey Gavrilov <alexey.gavrilov@mail.com>
---
 kernel/boot.s     | 15 ++++++++++-----
 libgcc/x86/crti.s |  5 +++++
 libgcc/x86/crtn.s |  3 +++
 makefile          | 10 +++++++++-
 4 files changed, 27 insertions(+), 6 deletions(-)
 create mode 100644 libgcc/x86/crti.s
 create mode 100644 libgcc/x86/crtn.s

diff --git a/kernel/boot.s b/kernel/boot.s
index 281e1ca..11175af 100644
--- a/kernel/boot.s
+++ b/kernel/boot.s
@@ -1,11 +1,16 @@
 section .text
-extern main
-extern _estack
-global _start:function (_start.end - _start)
+extern main, _estack, _init
+global _start:function
 _start:
-            mov esp, _estack
+            ; Stack setup
+            mov eax, _estack
+            ; Align stack to odd address
+            and eax, 0xFFFFFFFE
+            mov esp, eax
+
+            call _init
             call main
             cli
 .hang:      hlt
             jmp .hang
-.end:
+; .end:
diff --git a/libgcc/x86/crti.s b/libgcc/x86/crti.s
new file mode 100644
index 0000000..57cb8c1
--- /dev/null
+++ b/libgcc/x86/crti.s
@@ -0,0 +1,5 @@
+section .init
+global _init:function
+_init:
+            push ebp
+            mov ebp, esp
diff --git a/libgcc/x86/crtn.s b/libgcc/x86/crtn.s
new file mode 100644
index 0000000..537fa65
--- /dev/null
+++ b/libgcc/x86/crtn.s
@@ -0,0 +1,3 @@
+section .init
+            pop ebp
+            ret
diff --git a/makefile b/makefile
index 051eb0e..79152f8 100644
--- a/makefile
+++ b/makefile
@@ -25,13 +25,21 @@ endif
 OS_BINARY = $(BDIR)/kernel.bin
 BDIR = ./build
 
+BOOTOBJ = $(filter %boot.o, $(OBJ_FILES))
+CRTIOBJ = $(filter %crti.o, $(OBJ_FILES))
+CRTNOBJ = $(filter %crtn.o, $(OBJ_FILES))
+OBJ_REORDERING = $(filter-out $(BOOTOBJ), $(filter-out $(CRTIOBJ), $(filter-out $(CRTNOBJ), $(OBJ_FILES))))
+
+
 .PHONY: install $(SOURCE_FILES)
 
 build: startbuild $(SOURCE_FILES)
+	@echo "Bootfile: " $(BOOTOBJ) $(CRTIOBJ) $(CRTNOBJ)
+	@echo $(OBJ_FILES)
 	echo $(AFLAGS)
 	echo $(CFLAGS)
 	@echo "Link object files..."
-	$(LD) -o $(OS_BINARY) -L$(ARCHDIR) -T$(LDFILE) $(OBJ_FILES) $(LDFLAGS) 
+	$(LD) -o $(OS_BINARY) -L$(ARCHDIR) -T$(LDFILE) $(BOOTOBJ) $(CRTIOBJ) $(LIBS_PATH)crtbegin.o $(OBJ_REORDERING) $(LIBS_PATH)crtend.o $(CRTNOBJ) $(LDFLAGS) 
 	@echo "Project was built"
 
 $(CFILES):
-- 
cgit v1.2.3