Path and compile musl libc into kernel

.gitignore

@@ -1,5 +1,6 @@
 mittos.iso
 sysroot/
+external/
 
 *.d
 *.o

Makefile

@@ -7,7 +7,7 @@ KERNELMAKE := TARGET=${TARGET} $(MAKE) -C src/kernel
 
 DIST := $(BUILDROOT)/mittos.iso
 SYSROOT := $(BUILDROOT)/sysroot
-SYS_ITEMS := $(SYSROOT)/kernel
+SYS_ITEMS := $(SYSROOT)/kernel $(SYSROOT)/usr/lib/libc.a
 
 all: $(SYSROOT)/kernel
 
@@ -17,11 +17,14 @@ $(DIST): $(SYS_ITEMS)
 	$(BUILDROOT)/toolchain/setup-grub.sh
 	grub-mkrescue -o $@ $(SYSROOT)
 
-$(SYSROOT)/kernel: FORCE
+$(SYSROOT)/kernel: $(SYSROOT)/usr/lib/libc.a FORCE
 ifeq ($(shell make -sqC src/kernel || echo 1), 1)
 	$(KERNELMAKE) install
 endif
 
+$(SYSROOT)/usr/lib/libc.a:
+	toolchain/build-musl.sh
+
 .PHONY: all dist sysroot FORCE
 
 clean:

src/kernel/Makefile

@@ -11,10 +11,11 @@ CFLAGS := -Wall -Wextra -pedantic -ffreestanding -mcmodel=large
 CFLAGS += -ggdb -O0
 ASFLAGS += -ggdb
 CPPFLAGS += -I include
-LDFLAGS := -n -nostdlib -lgcc -T Link.ld
+LDFLAGS := -n -T Link.ld 
+LDLIBS := -nostdlib -lgcc -L/opt/sysroot/usr/lib -lc
 
 kernel: $(OBJ)
-	$(LINK.c) $^ -o $@
+	$(LINK.c) $^ $(LOADLIBES) $(LDLIBS) -o $@
 
 %.o: %.S.py
 	python3 $^ | $(COMPILE.S) $(DEPFLAGS) -x assembler-with-cpp - -o $@

src/kernel/boot/kmain.c

@@ -5,6 +5,7 @@
 #include <debug.h>
 #include <multiboot.h>
 #include <interrupts.h>
+#include <stdlib.h>
 
 struct kernel_boot_data_st kernel_boot_data;
 
@@ -26,6 +27,10 @@ void kmain(uint64_t multiboot_magic, void *multiboot_data)
 
     debug_info("Boot complete\n");
 
+    debug_info("Mallocing\n");
+    uint64_t a = malloc(100);
+    debug_info("Malloced %x\n", a);
+
     PANIC("End of kernel function!");
     
     debug_info("Broke out of panic");

src/kernel/lib/musl-glue.c

@@ -0,0 +1,50 @@
+#include <debug.h>
+
+long syscall0(long num)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d()\n", num);
+    return retval;
+}
+
+extern long syscall1(long num, long a1)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d(%x)\n", num, a1);
+    return retval;
+}
+
+extern long syscall2(long num, long a1, long a2)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d(%x, %x)\n", num, a1, a2);
+    return retval;
+}
+
+extern long syscall3(long num, long a1, long a2, long a3)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d(%x, %x, %x)\n", num, a1, a2, a3);
+    return retval;
+}
+
+extern long syscall4(long num, long a1, long a2, long a3, long a4)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d(%x, %x, %x, %x)\n", num, a1, a2, a3, a4);
+    return retval;
+}
+
+extern long syscall5(long num, long a1, long a2, long a3, long a4, long a5)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d(%x, %x, %x, %x, %x)\n", num, a1, a2, a3, a4, a5);
+    return retval;
+}
+
+extern long syscall6(long num, long a1, long a2, long a3, long a4, long a5, long a6)
+{
+    long retval = 0;
+    PANIC("Unknown syscall: %d(%x, %x, %x, %x, %x, %x)\n", num, a1, a2, a3, a4, a5, a6);
+    return retval;
+}

src/patch-musl/arch/x86_64/syscall_arch.h

@@ -0,0 +1,47 @@
+#define __SYSCALL_LL_E(x) (x)
+#define __SYSCALL_LL_O(x) (x)
+
+extern long syscall0(long);
+extern long syscall1(long, long);
+extern long syscall2(long, long, long);
+extern long syscall3(long, long, long, long);
+extern long syscall4(long, long, long, long, long);
+extern long syscall5(long, long, long, long, long, long);
+extern long syscall6(long, long, long, long, long, long, long);
+
+static __inline long __syscall0(long n)
+{
+    return syscall0(n);
+}
+static __inline long __syscall1(long n, long a1)
+{
+    return syscall1(n, a1);
+}
+static __inline long __syscall2(long n, long a1, long a2)
+{
+    return syscall2(n, a1, a2);
+}
+static __inline long __syscall3(long n, long a1, long a2, long a3)
+{
+    return syscall3(n, a1, a2, a3);
+}
+static __inline long __syscall4(long n, long a1, long a2, long a3, long a4)
+{
+    return syscall4(n, a1, a2, a3, a4);
+}
+static __inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5)
+{
+    return syscall5(n, a1, a2, a3, a4, a5);
+}
+static __inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6)
+{
+    return syscall6(n, a1, a2, a3, a4, a5, a6);
+}
+
+#define VDSO_USEFUL
+#define VDSO_CGT_SYM "__vdso_clock_gettime"
+#define VDSO_CGT_VER "LINUX_2.6"
+#define VDSO_GETCPU_SYM "__vdso_getcpu"
+#define VDSO_GETCPU_VER "LINUX_2.6"
+
+#define IPC_64 0

toolchain/build-musl.sh

@@ -0,0 +1,26 @@
+#!/bin/sh -e
+
+target=x86_64-elf
+SYSROOT=/opt/sysroot
+
+# Pull or update musl libc
+mkdir -p /opt/external && cd /opt/external
+[ -d musl ] || git clone --depth=1 git://git.musl-libc.org/musl
+cd musl
+git reset --hard
+git pull
+
+[ -d /opt/src/patch-musl ] && rsync -a /opt/src/patch-musl/ /opt/external/musl/
+
+mkdir -p /opt/external/build-musl && cd /opt/external/build-musl
+rm -r *
+../musl/configure \
+    --target=${target} \
+    --prefix=${SYSROOT}/usr \
+    --disable-shared \
+    --enable-debug \
+    CFLAGS="-O0 -mcmodel=large"
+
+make
+make install-headers
+make install

toolchain/build-toolchain.sh

@@ -5,14 +5,31 @@ apk add gmp-dev mpfr-dev mpc1-dev
 
 apk add make
 apk add grub-bios xorriso
-apk add python3
+apk add python3 git rsync
 
 rm -rf /var/cache/apk/*
 
 target=x86_64-elf
+SYSROOT=/opt/sysroot
 binutils=binutils-2.37
 gcc=gcc-11.2.0
 
+mkdir -p /opt/external
+cd /opt/external
+[ -d musl ] || git clone --depth=1 git://git.musl-libc.org/musl
+cd musl
+git reset --hard
+git pull
+
+cat > config.mak << EOF
+ARCH=x86_64
+prefix=${SYSROOT}/usr
+includedir=\$(prefix)/include
+EOF
+
+make install-headers
+
+# Build binutils
 cd /opt
 wget http://ftp.gnu.org/gnu/binutils/${binutils}.tar.gz
 tar -xf ${binutils}.tar.gz
@@ -21,11 +38,12 @@ mkdir binutils-build && cd binutils-build
   --target=${target} \
   --disable-nls \
   --disable-werror \
-  --with-sysroot \
+  --with-sysroot=${SYSROOT}
 
 make -j 4
 make install
 
+# Build gcc and libgcc
 cd /opt
 wget http://ftp.gnu.org/gnu/gcc/${gcc}/${gcc}.tar.gz
 tar -xf ${gcc}.tar.gz
@@ -34,7 +52,7 @@ mkdir gcc-build && cd gcc-build
   --target=${target} \
   --disable-nls \
   --enable-languages=c \
-  --without-headers \
+  --with-sysroot=${SYSROOT}
 
 make all-gcc all-target-libgcc -j 4
 make install-gcc install-target-libgcc