merge(toolchain): port an existing libc implementation

.github/workflows/build.yml

@@ -54,7 +54,11 @@ jobs:
 
     - name: Build Toolchain
       run: |
-        nix develop .#gcc --command make gcc TARGET=i686-dailyrun ARCH= CROSS_COMPILE=
+        nix develop .#gcc --command make gcc TARGET=i686-dailyrun ARCH= CROSS_COMPILE= GCC_CONFIGURE_FLAGS="--with-newlib"
+
+    - name: Build Newlib (libc)
+      run: |
+        nix develop .#newlib --command make newlib ARCH=i686 CROSS_COMPILE=
 
     - name: Build Kernel
       run: |

Makefile

@@ -91,6 +91,11 @@ define MAKE_RECURSIVE
 endef
 endif
 
+define newline
+
+
+endef
+
 all: kernel
 
 include $(TOOLCHAIN_DIR)/build.mk
@@ -119,12 +124,14 @@ compile_commands.json:
 	$(call ASSERT_EXE_EXISTS,bear)
 	$(SILENT)bear -- $(MAKE) -B all
 
+clean/%:
+	$(RM) -rf $(shell echo "$@" | sed "s/clean/$(BUILD_DIR)/")
+
 clean:
-	$(RM) -rf $(BUILD_DIR)
+	$(foreach to_clean,$(TO_CLEAN),$(RM) -rf $(to_clean) $(newline))
 
 distclean: clean
-	$(RM) -rf $(TOOLCHAIN_LOCATION)
-	$(RM) -rf $(BINUTILS_DIR) $(GCC_DIR)
+	$(foreach to_clean,$(TO_DISTCLEAN),$(RM) -rf $(to_clean) $(newline))
 
 .PHONY: clean distclean
 

README.md

@@ -33,6 +33,17 @@ $ make iso      # builds the kernel.iso file
 $ make qemu     # boots up qemu using the iso file
 ```
 
+### Toolchain
+
+If you do not already have an available `i686-elf` toolchain, a custom GCC target for this kernel (i686-dailyrun)
+is available for you to build inside the `toolchain` directory. Note that using this toolchain is required when
+building userland executables destined to be used with this kernel.
+
+```bash
+$ make gcc TARGET=i686-dailyrun ARCH= CROSS_COMPILE=
+$ make libc ARCH=i686 CROSS_COMPILE=
+```
+
 ## Testing
 
 I don't know how I can test kernel code, so all tests are performed manually for the time being ...

flake.nix

@@ -73,8 +73,9 @@
                 gnumake
                 pkg-config
                 autoconf-archive
-                autoconf
-                automake
+                autoconf269 # newlib requires using v2.69 exactly
+                automake115x
+                autogen
                 # Required libraries
                 gmp.dev
                 libmpc
@@ -90,6 +91,21 @@
                 export CROSS_COMPILE=
               '';
             };
+
+            newlib = pkgs.mkShell.override { stdenv = pkgs.stdenvNoCC; } {
+              hardeningDisable = [ "all" ];
+              buildInputs = with pkgs; [
+                gnumake
+                pkg-config
+                autoconf269 # newlib requires using v2.69 exactly
+                automake115x
+              ];
+
+              shellHook = ''
+                export ARCH=i686
+                export CROSS_COMPILE=
+              '';
+            };
           };
       }
     );

kernel/build.mk

@@ -50,7 +50,7 @@ DEPS += $(KERNEL_OBJS:.o=.d)
 
 KERNEL_LDSCRIPT := $(BUILD_DIR)/kernel/linker.ld
 
-KERNEL_LIBS := c algo path uacpi
+KERNEL_LIBS := k algo path uacpi
 
 $(KERNEL_BIN): CPPFLAGS += -DKERNEL -DUACPI_FORMATTED_LOGGING
 $(KERNEL_BIN): | $(KERNEL_LDSCRIPT)
@@ -80,4 +80,6 @@ qemu-server: $(KERNEL_ISO)
 	$(call ASSERT_EXE_EXISTS,$(QEMU))
 	$(SILENT)$(QEMU) -cdrom $(KERNEL_ISO) $(QEMU_ARGS)
 
+TO_CLEAN += $(BUILD_DIR)/$(KERNEL_DIR) $(KERNEL_BIN) $(KERNEL_ISO) $(BUILD_DIR)/kernel.map $(BUILD_DIR)/kernel.sym
+
 .PHONY: qemu qemu-server

lib/build.mk

@@ -21,15 +21,18 @@ $(BUILD_DIR)/$(1).a: $$($(1)_OBJS)
 
 DEPS += $$($(1)_OBJS:.o=.d)
 
+TO_CLEAN += $$(BUILD_DIR)/$(1).a
+
 endef
 
 define DEFINE_STATIC_LIBRARY
 $(call DEFINE_STATIC_LIBRARY_AT,$(1),$(1),include,src,$(2))
 endef
 
-include $(LIB_DIR)/libtest/build.mk
+TO_CLEAN += $(BUILD_DIR)/$(LIB_DIR)
 
-include $(LIB_DIR)/libc/build.mk
+include $(LIB_DIR)/libtest/build.mk
+include $(LIB_DIR)/libk/build.mk
 include $(LIB_DIR)/libalgo/build.mk
 include $(LIB_DIR)/libpath/build.mk
 include $(LIB_DIR)/uacpi/build.mk

lib/libk/build.mk

@@ -0,0 +1,5 @@
+$(eval $(call DEFINE_STATIC_LIBRARY,libk, \
+  string.c \
+  memcpy.c \
+  memset.c \
+))

lib/libc/src/string.c → lib/libk/src/string.c

@@ -22,15 +22,19 @@ char *strncpy(char *dst, const char *src, size_t n)
     return dst;
 }
 
-char *strlcpy(char *dst, const char *src, size_t n)
+size_t strlcpy(char *dst, const char *src, size_t n)
 {
-    if (n == 0)
-        return dst;
+    size_t i;
 
-    strncpy(dst, src, n - 1);
-    dst[n - 1] = '\0';
+    for (i = 0; i < n - 1; ++i) {
+        dst[i] = src[i];
+        if (dst[i] == '\0')
+            break;
+    }
 
-    return dst;
+    dst[i] = '0';
+
+    return i;
 }
 
 int strcmp(const char *s1, const char *s2)

toolchain/binutils/build.mk

@@ -41,3 +41,5 @@ $(BINUTILS_LD): binutils/configure
 	$(call MAKE_RECURSIVE,$(BINUTILS_BUILD_DIR),install,binutils/)
 
 .PHONY: binutils binutils/configure binutils/prepare
+
+TO_DISTCLEAN += $(BINUTILS_BUILD_DIR) $(BINUTILS_DIR)

toolchain/build.mk

@@ -10,3 +10,6 @@ export PATH := $(PREFIX)/bin:$(PREFIX)/usr/bin:$(PATH)
 
 include $(TOOLCHAIN_DIR)/binutils/build.mk
 include $(TOOLCHAIN_DIR)/gcc/build.mk
+include $(TOOLCHAIN_DIR)/newlib/build.mk
+
+TO_DISTCLEAN += $(TOOLCHAIN_LOCATION)

toolchain/gcc/build.mk

@@ -42,3 +42,5 @@ $(GCC_GCC): gcc/configure
 	$(call MAKE_RECURSIVE,$(GCC_BUILD_DIR),install-target-libgcc,gcc/)
 
 .PHONY: gcc gcc/configure gcc/prepare
+
+TO_DISTCLEAN += $(GCC_BUILD_DIR) $(GCC_DIR)

toolchain/newlib/.gitignore

@@ -0,0 +1 @@
+newlib-*/

toolchain/newlib/build.mk

@@ -0,0 +1,45 @@
+TOOLCHAIN_NEWLIB_DIR := $(TOOLCHAIN_DIR)/newlib
+
+NEWLIB_VERSION		:= 4.5.0.20241231
+NEWLIB_TAR_URL		:= ftp://sourceware.org/pub/newlib/newlib-$(NEWLIB_VERSION).tar.gz
+NEWLIB_DIR			:= $(TOOLCHAIN_NEWLIB_DIR)/newlib-$(NEWLIB_VERSION)
+NEWLIB_TAR			:= $(NEWLIB_DIR).tar.gz
+NEWLIB_BUILD_DIR	:= $(BUILD_DIR)/newlib-$(NEWLIB_VERSION)
+
+newlib/tar: $(NEWLIB_TAR)
+$(NEWLIB_TAR):
+	$(call COMPILE,WGET,$@)
+	$(SILENT)$(WGET) $(NEWLIB_TAR_URL) -O $@
+
+newlib/prepare: $(NEWLIB_DIR)
+$(NEWLIB_DIR): $(NEWLIB_TAR)
+	$(call COMPILE,EXTRACT,$@)
+	$(SILENT)tar xf $(NEWLIB_TAR) -C $(dir $@)
+	$(call LOG,PATCH,$@)
+	$(SILENT)cp -rf $(TOOLCHAIN_NEWLIB_DIR)/port/* $@
+	$(call LOG,RECONF,$@)
+	$(SILENT)cd $@/newlib && autoreconf -vfi $(SILENT_OUTPUT)
+	$(SILENT)cp -rf $(TOOLCHAIN_NEWLIB_DIR)/port/* $@
+
+newlib/configure: $(NEWLIB_BUILD_DIR)/config.status
+$(NEWLIB_BUILD_DIR)/config.status: $(NEWLIB_DIR)
+	$(call COMPILE,CONFIGURE,$@)
+	$(SILENT)\
+		cd $(dir $@) && \
+		$(PWD)/$(NEWLIB_DIR)/configure \
+			--target="$(TARGET)" \
+			--prefix="$(PREFIX)" \
+			$(NEWLIB_CONFIGURE_FLAGS) \
+		>  configure.log \
+		2> configure.err
+
+libc: newlib
+newlib: newlib/configure
+	$(call LOG,MAKE,newlib)
+	$(call MAKE_RECURSIVE,$(NEWLIB_BUILD_DIR),all CFLAGS='$(ASFLAGS)',newlib/)
+	$(call MAKE_RECURSIVE,$(NEWLIB_BUILD_DIR),install,newlib/)
+
+.PHONY: libc newlib newlib/configure newlib/prepare newlib/tar
+
+TO_CLEAN += $(NEWLIB_BUILD_DIR)
+TO_DISTCLEAN += $(NEWLIB_DIR)