Initial commit: Schunix as it stands before the SchOS rename

An x86-64 operating system built from xv6, now largely rewritten: SMP,
a copy-on-write root filesystem (SchFS), PCI/USB/virtio drivers, a TTF
rasteriser, and a Linux-numbered syscall ABI.

No history before this point -- the tree was never under version control.
This commit exists so the rename that follows has something to undo to.

lib/user.ld

@@ -0,0 +1,43 @@
+/* Simple linker script for the JOS kernel.
+   See the GNU ld 'info' manual ("info ld") to learn the syntax. */
+
+/* OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") */
+/* OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64") */
+OUTPUT_FORMAT("elf64-x86-64")
+OUTPUT_ARCH(i386:x86-64)
+ENTRY(main)
+
+SECTIONS
+{
+	/* Link the kernel at this address: "." means the current address */
+        /* Must be equal to KERNLINK */
+	. = 0x1000;
+
+	PROVIDE(begin = .);
+
+	.text : {
+		*(.text .rela.text .stub .text.* .gnu.linkonce.t.*)
+	}
+
+	.rodata : {
+		*(.rodata .rodata.* .gnu.linkonce.r.*)
+	}
+
+	/* The data segment */
+	.data : {
+		*(.data)
+	}
+
+	.bss : {
+		*(.bss)
+		*(COMMON)
+	}
+
+	. = ALIGN(0x1000);
+
+	PROVIDE(end = .);
+
+	/DISCARD/ : {
+		*(.eh_frame .rela.eh_frame .note.GNU-stack)
+	}
+}