feat/kernel: Added support for Kconfig and flanterm if needed

.gitignore

@@ -4,3 +4,4 @@ limine/
 ovmf/
 release/
 *.log
+.config*

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "external/flanterm"]
+	path = external/flanterm
+	url = https://codeberg.org/mintsuki/flanterm

.vscode/c_cpp_properties.json

@@ -10,7 +10,9 @@
             "cppStandard": "${default}",
             "intelliSenseMode": "linux-gcc-x64",
             "defines": [
-                "LIMINE_API_REVISION=3"
+                "LIMINE_API_REVISION=3",
+                "FLANTERM_SUPPORT=1",
+                "BUILD_MODE=\"\""
             ]
         }
     ],

.vscode/settings.json

@@ -13,6 +13,10 @@
         "emk.h": "c",
         "heap.h": "c",
         "vmm.h": "c",
-        "align.h": "c"
+        "align.h": "c",
+        "cpu.h": "c",
+        "nanoprintf.h": "c",
+        "flanterm.h": "c",
+        "serial.h": "c"
     }
 }

GNUmakefile

@@ -2,7 +2,7 @@
 MAKEFLAGS += -rR
 .SUFFIXES:
 
-QEMUFLAGS := -m 2G -serial stdio -display none
+QEMUFLAGS := -m 2G -serial stdio
 USER_QEMUFLAGS ?=
 IMAGE_NAME := release/emk
 

external/flanterm

@@ -0,0 +1 @@
+Subproject commit bdecdcb1b7dad05ab5249e2c3e4d2c27a661e864

kernel/GNUmakefile

@@ -8,19 +8,34 @@ BINDIR := bin
 
 TARGET := $(BINDIR)/emk.elf
 
+KCONFIG ?= kconfig-mconf
+CONFIG := .config
+
+ifneq ("$(wildcard $(CONFIG))","")
+    include $(CONFIG)
+endif
+
 CC := gcc
 AS := gcc
 NASM := nasm
 
-# Build mode configuration
-BUILD_MODE ?= dev
+ifeq ($(BUILD_MODE),)
+    ifeq ($(CONFIG_BUILD_MODE_DEBUG),y)
+        BUILD_MODE := debug
+    else ifeq ($(CONFIG_BUILD_MODE_RELEASE),y)
+        BUILD_MODE := release
+    else
+        BUILD_MODE := debug
+    endif
+endif
+
 ifeq ($(BUILD_MODE),release)
     CFLAGS := -Os -pipe -Wall -Wextra -Werror -std=gnu11 -ffreestanding \
               -fno-stack-protector -fno-stack-check -fno-PIC \
               -ffunction-sections -fdata-sections -m64 -march=x86-64 \
               -mno-80387 -mno-mmx -mno-sse -mno-sse2 -mno-red-zone \
               -mcmodel=kernel -fno-unwind-tables -fno-asynchronous-unwind-tables \
-              -s -Wno-unused-variable
+              -s -Wno-unused-variable -DBUILD_MODE=\"release\"
     NASMFLAGS :=
     LDFLAGS := -nostdlib -static -z max-page-size=0x1000 -Wl,--gc-sections \
                -T linker.ld -Wl,-m,elf_x86_64 -Wl,--strip-all
@@ -29,7 +44,7 @@ else
               -fno-stack-protector -fno-stack-check -fno-PIC \
               -ffunction-sections -fdata-sections -m64 -march=x86-64 \
               -mno-80387 -mno-mmx -mno-sse -mno-sse2 -mno-red-zone \
-              -mcmodel=kernel -Wno-unused-variable
+              -mcmodel=kernel -Wno-unused-variable -DBUILD_MODE=\"dev\"
     NASMFLAGS := -F dwarf -g
     LDFLAGS := -nostdlib -static -z max-page-size=0x1000 -Wl,--gc-sections \
                -T linker.ld -Wl,-m,elf_x86_64
@@ -37,14 +52,48 @@ endif
 
 CPPFLAGS := -I../external -I$(SRCDIR) -MMD -MP -DLIMINE_API_REVISION=3
 
-SRCS := $(shell find $(SRCDIR) -type f \( -name '*.c' -o -name '*.S' -o -name '*.asm' \))
-OBJS := $(patsubst %.c,$(OBJDIR)/%.o,$(filter %.c,$(SRCS))) \
-        $(patsubst %.S,$(OBJDIR)/%.o,$(filter %.S,$(SRCS))) \
-        $(patsubst %.asm,$(OBJDIR)/%.o,$(filter %.asm,$(SRCS)))
+IMPLICIT_SRCS :=
+ifeq ($(CONFIG_KERNEL_HEAP_FF),y)
+    IMPLICIT_SRCS += src/mm/heap/ff.c
+else
+    $(error Error: No heap algorithm was defined. Please run "make menuconfig" and select one.)
+endif
+
+ifeq ($(CONFIG_ENABLE_FLANTERM),y)
+    IMPLICIT_SRCS += ../external/flanterm/flanterm.c
+    IMPLICIT_SRCS += ../external/flanterm/backends/fb.c
+    CFLAGS += -I../external/flanterm/ -DFLANTERM_SUPPORT=1
+endif
+
+EXCLUDE_SRCS := \
+    src/mm/heap/ff.c \
+    ../external/flanterm/flanterm.c \
+    ../external/flanterm/backends/fb.c
+EXCLUDE_PATTERNS := $(foreach file,$(EXCLUDE_SRCS),! -path "$(file)")
+
+SRCS := $(IMPLICIT_SRCS) \
+        $(shell find $(SRCDIR) -type f \( -name '*.c' -o -name '*.S' -o -name '*.asm' \) $(EXCLUDE_PATTERNS))
+
+define src_to_obj
+$(OBJDIR)/$(patsubst ../%,%,$(1:.c=.o))
+endef
+
+define src_to_obj_s
+$(OBJDIR)/$(patsubst ../%,%,$(1:.S=.o))
+endef
+
+define src_to_obj_asm
+$(OBJDIR)/$(patsubst ../%,%,$(1:.asm=.o))
+endef
+
+OBJS := 
+OBJS += $(foreach f,$(filter %.c,$(SRCS)),$(call src_to_obj,$(f)))
+OBJS += $(foreach f,$(filter %.S,$(SRCS)),$(call src_to_obj_s,$(f)))
+OBJS += $(foreach f,$(filter %.asm,$(SRCS)),$(call src_to_obj_asm,$(f)))
 
 DEPS := $(OBJS:.o=.d)
 
-.PHONY: all clean distclean
+.PHONY: all clean distclean menuconfig
 all: $(TARGET)
 
 $(OBJDIR) $(BINDIR):
@@ -54,16 +103,31 @@ $(TARGET): $(OBJS) | $(BINDIR)
 	@echo "  LD    $@"
 	@$(CC) $(LDFLAGS) -o $@ $(OBJS)
 
+$(OBJDIR)/%.o: ../%.c | $(OBJDIR)
+	@mkdir -p $(dir $@)
+	@echo "  CC    ../$*"
+	@$(CC) $(CPPFLAGS) $(CFLAGS) -c ../$*.c -o $@
+
 $(OBJDIR)/%.o: %.c | $(OBJDIR)
 	@mkdir -p $(dir $@)
 	@echo "  CC    $<"
 	@$(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@
 
+$(OBJDIR)/%.o: ../%.S | $(OBJDIR)
+	@mkdir -p $(dir $@)
+	@echo "  AS    ../$*"
+	@$(AS) $(CPPFLAGS) $(CFLAGS) -c ../$*.S -o $@
+
 $(OBJDIR)/%.o: %.S | $(OBJDIR)
 	@mkdir -p $(dir $@)
 	@echo "  AS    $<"
 	@$(AS) $(CPPFLAGS) $(CFLAGS) -c $< -o $@
 
+$(OBJDIR)/%.o: ../%.asm | $(OBJDIR)
+	@mkdir -p $(dir $@)
+	@echo "  NASM  ../$*"
+	@$(NASM) $(NASMFLAGS) ../$*.asm -o $@
+
 $(OBJDIR)/%.o: %.asm | $(OBJDIR)
 	@mkdir -p $(dir $@)
 	@echo "  NASM  $<"
@@ -77,4 +141,7 @@ distclean: clean
 	@echo "  DISTCLEAN"
 	@rm -rf $(BINDIR)
 
+menuconfig: clean
+	@$(KCONFIG) Kconfig
+
 -include $(DEPS)

kernel/Kconfig

@@ -0,0 +1,33 @@
+mainmenu "EMK Build Configuration"
+
+choice
+    prompt "Build Mode"
+    default BUILD_MODE_DEBUG
+
+config BUILD_MODE_DEBUG
+    bool "Debug"
+    help
+      Build with debug symbols and no optimizations.
+
+config BUILD_MODE_RELEASE
+    bool "Release"
+    help
+      Build with optimizations and no debug symbols.
+
+endchoice
+
+choice
+    prompt "Kernel Heap Algorithm"
+    default KERNEL_HEAP_FF
+
+config KERNEL_HEAP_FF
+    bool "First-Fit"
+    help
+      Use the First-Fit memory allocation algorithm (ff.c).
+
+endchoice
+
+config ENABLE_FLANTERM
+    bool "Enable Flanterm Support"
+    help
+      Includes support for the Flanterm terminal emulator. Useful for debugging real hardware.

kernel/src/boot/emk.h

@@ -5,6 +5,9 @@
 #include <boot/limine.h>
 #include <stdint.h>
 #include <mm/vmm.h>
+#if FLANTERM_SUPPORT
+#include <flanterm/flanterm.h>
+#endif // FLANTERM_SUPPORT
 
 extern uint64_t hhdm_offset;
 extern struct limine_memmap_response *memmap;
@@ -18,4 +21,16 @@ extern vctx_t *kvm_ctx;
 
 #define BIT(x) (1ULL << (x))
 
+#ifndef FLANTERM_SUPPORT
+#define FLANTERM_SUPPORT 0
+#endif // FLANTERM_SUPPORT
+
+#ifndef BUILD_MODE
+#define BUILD_MODE "unknown"
+#endif // BUILD_MODE
+
+#if FLANTERM_SUPPORT
+extern struct flanterm_context *ft_ctx;
+#endif // FLANTERM_SUPPORT
+
 #endif // EMK_H

kernel/src/emk.c

@@ -13,6 +13,10 @@
 #include <arch/paging.h>
 #include <mm/vmm.h>
 #include <mm/heap.h>
+#if FLANTERM_SUPPORT
+#include <flanterm/flanterm.h>
+#include <flanterm/backends/fb.h>
+#endif // FLANTERM_SUPPORT
 
 __attribute__((used, section(".limine_requests"))) static volatile LIMINE_BASE_REVISION(3);
 __attribute__((used, section(".limine_requests"))) static volatile struct limine_memmap_request memmap_request = {
@@ -24,6 +28,11 @@ __attribute__((used, section(".limine_requests"))) static volatile struct limine
 __attribute__((used, section(".limine_requests"))) volatile struct limine_executable_address_request kernel_address_request = {
     .id = LIMINE_EXECUTABLE_ADDRESS_REQUEST,
     .response = 0};
+#if FLANTERM_SUPPORT
+__attribute__((used, section(".limine_requests"))) volatile struct limine_framebuffer_request framebuffer_request = {
+    .id = LIMINE_FRAMEBUFFER_REQUEST,
+    .response = 0};
+#endif // FLANTERM_SUPPORT
 __attribute__((used, section(".limine_requests_start"))) static volatile LIMINE_REQUESTS_START_MARKER;
 __attribute__((used, section(".limine_requests_end"))) static volatile LIMINE_REQUESTS_END_MARKER;
 
@@ -34,6 +43,10 @@ uint64_t kphys = 0;
 uint64_t kstack_top = 0;
 vctx_t *kvm_ctx = NULL;
 
+#if FLANTERM_SUPPORT
+struct flanterm_context *ft_ctx = NULL;
+#endif // FLANTERM_SUPPORT
+
 void emk_entry(void)
 {
     __asm__ volatile("movq %%rsp, %0" : "=r"(kstack_top));
@@ -42,8 +55,28 @@ void emk_entry(void)
         /* Just halt and say nothing */
         hcf();
     }
+
+    /* Init flanterm if we compiled with support */
+#if FLANTERM_SUPPORT
+    struct limine_framebuffer *framebuffer = framebuffer_request.response->framebuffers[0];
+    ft_ctx = flanterm_fb_init(
+        NULL,
+        NULL,
+        framebuffer->address, framebuffer->width, framebuffer->height, framebuffer->pitch,
+        framebuffer->red_mask_size, framebuffer->red_mask_shift,
+        framebuffer->green_mask_size, framebuffer->green_mask_shift,
+        framebuffer->blue_mask_size, framebuffer->blue_mask_shift,
+        NULL,
+        NULL, NULL,
+        NULL, NULL,
+        NULL, NULL,
+        NULL, 0, 0, 1,
+        0, 0,
+        0);
+#endif // FLANTERM_SUPPORT
+
     log_early("Experimental Micro Kernel (EMK) 1.0 Copytright (c) 2025 Piraterna");
-    log_early("Compiled at %s %s", __TIME__, __DATE__);
+    log_early("Compiled at %s %s, emk1.0-%s, flanterm support: %s", __TIME__, __DATE__, BUILD_MODE, FLANTERM_SUPPORT ? "yes" : "no");
 
     if (!LIMINE_BASE_REVISION_SUPPORTED)
     {

kernel/src/util/kprintf.c

@@ -1,6 +1,10 @@
 /* EMK 1.0 Copyright (c) 2025 Piraterna */
-#include <dev/serial.h>
 #include <util/kprintf.h>
+#include <dev/serial.h>
+#include <boot/emk.h>
+#if FLANTERM_SUPPORT
+#include <flanterm/flanterm.h>
+#endif // FLANTERM_SUPPORT
 
 #define NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS 1
 #define NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS 1
@@ -22,6 +26,10 @@ int kprintf(const char *fmt, ...)
     if (length >= 0 && length < (int)sizeof(buffer))
     {
         serial_write(COM1, (uint8_t *)buffer, length);
+#if FLANTERM_SUPPORT
+        if (ft_ctx)
+            flanterm_write(ft_ctx, (char *)buffer, length);
+#endif // FLANTERM_SUPPORT
     }
 
     va_end(args);