From 71e4f3812982dba2efb471283d310224e8db363e Mon Sep 17 00:00:00 2001
From: "Kartik K. Agaram" <vc@akkartik.com>
Date: Wed, 3 Mar 2021 22:09:50 -0800
Subject: 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.
---
 apps/ex10.subx | 69 ----------------------------------------------------------
 1 file changed, 69 deletions(-)
 delete mode 100644 apps/ex10.subx

(limited to 'apps/ex10.subx')

diff --git a/apps/ex10.subx b/apps/ex10.subx
deleted file mode 100644
index 7ec86202..00000000
--- a/apps/ex10.subx
+++ /dev/null
@@ -1,69 +0,0 @@
-# String comparison: return 1 iff the two args passed in at the commandline are equal.
-#
-# To run:
-#   $ ./bootstrap translate init.linux apps/ex10.subx -o apps/ex10
-#   $ ./bootstrap run apps/ex10 abc abd
-# Expected result:
-#   $ echo $?
-#   0  # false
-
-== code
-#   instruction                     effective address                                                   register    displacement    immediate
-# . op          subop               mod             rm32          base        index         scale       r32
-# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
-
-Entry:  # return argv-equal(argv[1], argv[2])
-#       At the start of a SubX program:
-#         argc: *esp
-#         argv[0]: *(esp+4)
-#         argv[1]: *(esp+8)
-#         ...
-    # . prologue
-    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
-    # argv-equal(argv[1], argv[2])
-    # . . push argv[2]
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
-    # . . push argv[1]
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
-    # . . call
-    e8/call argv-equal/disp32
-    # exit(eax)
-    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           0/r32/eax   .               .                 # copy eax to ebx
-    e8/call  syscall_exit/disp32
-
-# compare two null-terminated ascii strings
-# reason for the name: the only place we should have null-terminated ascii strings is from commandline args
-argv-equal:  # (s1, s2): null-terminated ascii strings -> eax: boolean
-    # initialize s1 (ecx) and s2 (edx)
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/esp  4/index/none  .           1/r32/ecx   4/disp8         .                 # copy *(esp+4) to ecx
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/esp  4/index/none  .           2/r32/edx   8/disp8         .                 # copy *(esp+8) to edx
-$argv-equal:loop:
-    # c1/eax, c2/ebx = *s1, *s2
-    b8/copy-to-eax  0/imm32
-    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
-    bb/copy-to-ebx  0/imm32
-    8a/copy-byte                    0/mod/indirect  2/rm32/edx    .           .             .           3/r32/BL    .               .                 # copy byte at *edx to BL
-    # if (c1 == 0) break
-    3d/compare-eax-and  0/imm32/null
-    74/jump-if-=  $argv-equal:break/disp8
-    # if (c1 != c2) return false
-    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           3/r32/ebx   .               .                 # compare eax and ebx
-    75/jump-if-!=  $argv-equal:false/disp8
-    # ++s1, ++s2
-    41/increment-ecx
-    42/increment-edx
-    # end while
-    eb/jump  $argv-equal:loop/disp8
-$argv-equal:break:
-    # if (c2 == 0) return true
-    81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0/imm32/null      # compare ebx
-    75/jump-if-!=  $argv-equal:false/disp8
-$argv-equal:success:
-    b8/copy-to-eax  1/imm32
-    c3/return
-    # return false
-$argv-equal:false:
-    b8/copy-to-eax  0/imm32
-    c3/return
-
-# . . vim:nowrap:textwidth=0
-- 
cgit 1.4.1-2-gfad0