Implement kernel bootstrap up to building Linux.

parts.rst

@@ -7,6 +7,7 @@
 
 .. SPDX-License-Identifier: CC-BY-SA-4.0
 
+
 bootstrap-seeds
 ===============
 
@@ -14,7 +15,10 @@ This is where it all begins. We start with the two raw binary seeds ``hex0-seed`
 
 First, we use those seeds to rebuild themselves.
 
-Note that all early steps before ``mes`` are part of `stage0-posix <https://github.com/oriansj/stage0-posix>`_.
+Note that all early compilers before ``mes`` are part of `stage0-posix <https://github.com/oriansj/stage0-posix>`_.
+
+A kernel boostrapping option is also available at the beginning. The ``hex0-seed`` can be used to compile the ``builder-hex0`` kernel which has its own built-in shell, ``hex0`` compiler and ``src`` tool to load files into its file system. ``builder-hex0`` runs stage0-posix and then builds ``mes`` and ``tcc``. It then builds and launches the `Fiwix <https://github.com/mikaku/Fiwix>` kernel which runs the build until Linux takes over.
+
 
 hex0
 ====
@@ -34,6 +38,12 @@ In the first steps we use initial ``hex0`` binary seed to rebuild ``kaem-optiona
 
 ``hex0`` can be approximated with: ``sed 's/[;#].*$//g' $input_file | xxd -r -p > $output_file``
 
+
+builder-hex0 (kernel bootstrap)
+===============================
+If the kernel-bootstrap option is enabled then the ``builder-hex0`` kernel boots from a hard drive and loads an enormous shell script which embeds files (loaded with the ``src`` command) and the initial commands to build ``hex0-seed``, ``kaem-optional-seed``, and the command which launches stage0-posix using ``kaem-optional-seed`` and the stage0-posix launch script ``kaem.x86``. Builder-hex0 is written in hex0 and can be compiled with any one of ``hex0-seed``, ``sed``, the tiny ``builder-hex0-mini`` boot kernel or it can build itself.
+
+
 kaem-optional
 =============
 
@@ -189,6 +199,29 @@ using older versions compilable by tinycc. Prior to this point, all tools
 have been adapted significantly for the bootstrap; now, we will be using
 old tooling instead.
 
+Fiwix 1.4.0-lb1 (kernel bootstrap)
+==================================
+
+If the kernel bootstrap option is enabled then the Fiwix kernel is built next.
+This is a Linux clone which is much simpler to understand and build than Linux.
+This version of Fiwix is a fork of 1.4.0 that contains many modifications and
+enhancements to support live-boostrap.
+
+lwext4 1.0.0 (kernel bootstrap)
+===============================
+
+If the kernel bootstrap option is enabled then `lwext4 <https://github.com/gkostka/lwext4>`
+is built next. This is a library for creating ext2/3/4 file systems from user land.
+This is combined with a program called ``make_fiwix_initrd.c`` which creates
+and populates an ext2 files system which Fiwix uses for an initial ram drive (initrd).
+This file system contains all of the files necessary to build Linux.
+
+kexec-fiwix (kernel bootstrap)
+==============================
+
+If the kernel bootstrap option is enabled then a C program `kexec-fiwix` is compiled
+and run which places the Fiwix ram drive in memory and launches the Fiwix kernel.
+
 make 3.82
 =========
 
@@ -597,6 +630,7 @@ musl 1.2.3
 GCC can build the latest as of the time of writing musl version.
 
 We also don't need any of the TCC patches that we used before.
+To accomodate Fiwix, there are patches to avoid syscalls set_thread_area and clone.
 
 gcc 4.0.4
 =========
@@ -652,6 +686,11 @@ The next step is not a package, but the creation of the sysb rootfs, containing
 all of the scripts for sysb (which merely move to sysc). Again, this is only
 done in non-chroot mode, because sysb does not exist in chroot mode.
 
+musl 1.2.3
+==========
+Prior to building and booting Linux, musl is rebuilt yet again with syscalls
+``clone`` and ``set_thread_area`` enabled for Linux thread support.
+
 Linux kernel 4.9.10
 ===================
 
@@ -702,6 +741,15 @@ and is built with GNU readline support so it can be used as a fully-featured
 interactive shell. ``autoconf-2.69`` is used to regenerate the configure
 script and ``bison`` is used to recreate some included generated files.
 
+curl 7.83.0
+===========
+
+Curl is built in sysc because Linux must be running with support for threads.
+Curl requires musl 1.2.3 with thread support which was built at the end of sysa.
+Curl is built first in sysc so the rest of the packages can be downloaded.
+Note that the tar file for curl itself was copied over from sysa because
+curl is not yet available to download it.
+
 xz 5.4.1
 ========