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, 0 insertions, 81 deletions

diff --git a/apps/advent2020/5b.mu b/apps/advent2020/5b.mu
deleted file mode 100644
index fbc0d618..00000000
--- a/apps/advent2020/5b.mu
+++ /dev/null
@@ -1,81 +0,0 @@
-# https://adventofcode.com/2020/day/5
-#
-# To run (on Linux):
-#   $ git clone https://github.com/akkartik/mu
-#   $ cd mu
-#   $ ./translate_mu apps/advent2020/5b.mu
-#   $ ./a.elf < input
-#
-# You'll need to register to download the 'input' file for yourself.
-
-fn main -> _/ebx: int {
-  var pass-storage: (array int 0x400)  # 1k ints
-  var pass/esi: (addr array int) <- address pass-storage
-  # phase 1: populate pass array
-  var line-storage: (stream byte 0x10)  # 16 bytes is enough
-  var line/edx: (addr stream byte) <- address line-storage
-  {
-    # read line from stdin
-    clear-stream line
-    read-line-from-real-keyboard line
-    # if line is empty (not even a newline), quit
-    var done?/eax: boolean <- stream-empty? line
-    compare done?, 0/false
-    break-if-!=
-    # process line
-    var seat-id/eax: int <- convert-from-binary line
-    var dest/eax: (addr int) <- index pass, seat-id
-    copy-to *dest, 1
-    loop
-  }
-  # phase 2: skip empty seats
-  var i/eax: int <- copy 0
-  {
-    compare i, 0x400
-    break-if->=
-    var src/ecx: (addr int) <- index pass, i
-    compare *src, 0
-    break-if-!=
-    i <- increment
-    loop
-  }
-  # phase 3: skip non-empty seats
-  {
-    compare i, 0x400
-    break-if->=
-    var src/ecx: (addr int) <- index pass, i
-    compare *src, 0
-    break-if-=
-    i <- increment
-    loop
-  }
-  print-int32-decimal 0, i
-  print-string 0, "\n"
-  return 0
-}
-
-fn convert-from-binary in: (addr stream byte) -> _/eax: int {
-  var result/edi: int <- copy 0
-  var i/ecx: int <- copy 9  # loop counter and also exponent
-  {
-    compare i, 0
-    break-if-<
-    var c/eax: byte <- read-byte in
-    var bit/edx: int <- copy 0
-    {
-      compare c, 0x42/B
-      break-if-!=
-      bit <- copy 1
-    }
-    {
-      compare c, 0x52/R
-      break-if-!=
-      bit <- copy 1
-    }
-    var bit-value/eax: int <- repeated-shift-left bit, i
-    result <- add bit-value
-    i <- decrement
-    loop
-  }
-  return result
-}