From eb4055da303c6391a0ca8c117fb712ad782831a2 Mon Sep 17 00:00:00 2001
From: Nedko Arnaudov <esp32@goody>
Date: Wed, 13 Jun 2018 01:35:57 +0300
Subject: [PATCH] Document some design decisions

---
 doc/boot.txt  |  4 ++++
 doc/shell.txt | 15 +++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 doc/boot.txt
 create mode 100644 doc/shell.txt

diff --git a/doc/boot.txt b/doc/boot.txt
new file mode 100644
index 0000000..26836a9
--- /dev/null
+++ b/doc/boot.txt
@@ -0,0 +1,4 @@
+Boot process is the esp-idf boot process, with bootloader, partition
+table and at least one application partition. The bootloader and
+application messages showing boot progress are sent to UART0. Then
+the application provides text shell through UART0.
diff --git a/doc/shell.txt b/doc/shell.txt
new file mode 100644
index 0000000..f493083
--- /dev/null
+++ b/doc/shell.txt
@@ -0,0 +1,15 @@
+The boot process ends with apeos providing interactive text shell on
+UART0.
+
+The shell allows execution of programs. Programs accept parameters
+through C-runtime-like argc/argv mechanism. For receiving input and
+providing output to user running them, programs have access to
+two C-runtime-like streams: stdin and stdout. These two streams are
+the primary mean for interacting with user that ordered program
+execution.
+
+Programs are implemented as C-like functions, with program entry code
+residing at address fixed when the esp-idf application providing them
+is built. Thus, program execution is a matter of parsing the
+command-line, converting the parse result to argc/argv and calling
+a function with ABI fixed for all apeos programs.
-- 
2.11.4.GIT