From 4a85d2ec9ee011e3add6077fbe72368c86b152a5 Mon Sep 17 00:00:00 2001
From: David Garske <david@wolfssl.com>
Date: Tue, 16 Jan 2024 10:45:45 -0800
Subject: [PATCH] Added documentation for the two parsers (ELF and FDT).

---
 tools/elf-parser/Makefile  |  2 +-
 tools/elf-parser/README.md | 23 +++++++++++++++++++++++
 tools/fdt-parser/README.md | 30 ++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 tools/elf-parser/README.md
 create mode 100644 tools/fdt-parser/README.md

diff --git a/tools/elf-parser/Makefile b/tools/elf-parser/Makefile
index 585d8a973..fd89e343c 100644
--- a/tools/elf-parser/Makefile
+++ b/tools/elf-parser/Makefile
@@ -4,7 +4,7 @@
 
 CC=gcc
 CFLAGS=-Wall -g -ggdb
-CFLAGS+=-I../../include -DWOLFBOOT_ELF -DELF_PARSER -DDEBUG_ELF -DPRINTF_ENABLED
+CFLAGS+=-I../../include -DWOLFBOOT_ELF -DELF_PARSER -DPRINTF_ENABLED
 EXE=elf-parser
 
 LIBS=
diff --git a/tools/elf-parser/README.md b/tools/elf-parser/README.md
new file mode 100644
index 000000000..9e192b91c
--- /dev/null
+++ b/tools/elf-parser/README.md
@@ -0,0 +1,23 @@
+# ELF Parser Tool
+
+This tool demonstrates parsing ELF32/ELF64, showing the clear/load sections and entry point.
+
+## Building elf-parser
+
+From root: `make elf-parser`
+OR
+From `tools/elf-parser` use `make clean && make`
+
+## Example Output
+
+```sh
+% ./tools/elf-parser/elf-parser wolfboot.elf
+ELF Parser:
+Loading elf at 0x7f9a18008000
+Found valid elf32 (little endian)
+Program Headers 2 (size 32)
+	Load 18340 bytes (offset 0x10000) to 0x8000000 (p 0x8000000)
+	Clear 72 bytes at 0x20000000 (p 0x80047a4)
+Entry point 0x8000000
+Return 0, Load 0x8000000
+```
diff --git a/tools/fdt-parser/README.md b/tools/fdt-parser/README.md
new file mode 100644
index 000000000..4b5045fc1
--- /dev/null
+++ b/tools/fdt-parser/README.md
@@ -0,0 +1,30 @@
+# Flattened Device Tree (FDT) Parser
+
+This tool uses our internal FDT (fdt.c) parsing code to dump the device tree. There is also a `-t` option that tests making several updates to the device tree.
+
+## Building fdt-parser
+
+From root: `make fdt-parser`
+OR
+From `tools/fdt-parser` use `make clean && make`
+
+## Example Output
+
+```sh
+% ./tools/fdt-parser/fdt-parser ./tools/fdt-parser/nxp_t1024.dtb
+FDT Parser (./tools/fdt-parser/nxp_t1024.dtb):
+FDT Version 17, Size 31102
+root (node offset 0, depth 1, len 0):
+	compatible (prop offset 8, len 13): fsl,T1024RDB
+	#address-cells (prop offset 36, len 4): ....| 00 00 00 02
+	#size-cells (prop offset 52, len 4): ....| 00 00 00 02
+	interrupt-parent (prop offset 68, len 4): ....| 00 00 00 01
+	model (prop offset 84, len 13): fsl,T1024RDB
+	cpus (node offset 112, depth 2, len 4):
+		power-isa-version (prop offset 124, len 5): 2.06
+		power-isa-b (prop offset 144, len 0): NULL
+		power-isa-e (prop offset 156, len 0): NULL
+		power-isa-atb (prop offset 168, len 0): NULL
+		power-isa-cs (prop offset 180, len 0): NULL
+...
+```