7842 - new directory organization

Baremetal is now the default build target and therefore has its sources
at the top-level. Baremetal programs build using the phase-2 Mu toolchain
that requires a Linux kernel. This phase-2 codebase which used to be at
the top-level is now under the linux/ directory. Finally, the phase-2 toolchain,
while self-hosting, has a way to bootstrap from a C implementation, which
is now stored in linux/bootstrap. The bootstrap C implementation uses some
literate programming tools that are now in linux/bootstrap/tools.

So the whole thing has gotten inverted. Each directory should build one
artifact and include the main sources (along with standard library). Tools
used for building it are relegated to sub-directories, even though those
tools are often useful in their own right, and have had lots of interesting
programs written using them.

A couple of things have gotten dropped in this process:
  - I had old ways to run on just a Linux kernel, or with a Soso kernel.
    No more.
  - I had some old tooling for running a single test at the cursor. I haven't
    used that lately. Maybe I'll bring it back one day.

The reorg isn't done yet. Still to do:
  - redo documentation everywhere. All the README files, all other markdown,
    particularly vocabulary.md.
  - clean up how-to-run comments at the start of programs everywhere
  - rethink what to do with the html/ directory. Do we even want to keep
    supporting it?

In spite of these shortcomings, all the scripts at the top-level, linux/
and linux/bootstrap are working. The names of the scripts also feel reasonable.
This is a good milestone to take stock at.

1 files changed, 16 insertions, 0 deletions

diff --git a/ex5.mu b/ex5.mu
new file mode 100644
index 00000000..1f3bea10
--- /dev/null
+++ b/ex5.mu
@@ -0,0 +1,16 @@
+# Draw a single line of ASCII text using the built-in font (GNU unifont)
+# Also demonstrates bounds-checking _before_ drawing.
+#
+# To build a disk image:
+#   ./translate_mu_baremetal baremetal/ex5.mu     # emits disk.img
+# To run:
+#   qemu-system-i386 disk.img
+# Or:
+#   bochs -f baremetal/boot.bochsrc               # boot.bochsrc loads disk.img
+#
+# Expected output: text in green near the top-left corner of screen
+
+fn main {
+  var dummy/eax: int <- draw-text-rightward 0/screen, "hello from baremetal Mu!", 0x10/x, 0x400/xmax, 0x10/y, 0xa/color
+  dummy <- draw-text-rightward 0/screen, "you shouldn't see this", 0x10/x, 0xa0/xmax, 0x30/y, 0x3/color  # xmax is too narrow
+}