From ae03ddda19777a401ad01686690f33ef674bb84b Mon Sep 17 00:00:00 2001
From: David Garske <david@wolfssl.com>
Date: Fri, 28 Jun 2024 12:29:22 -0700
Subject: [PATCH] Switch to using a fixed flash location for wrapped public
 key, so it can be flash on its own.

---
 arch.mk                 |  3 ---
 docs/Renesas.md         | 26 ++++++++++++++++++++++----
 hal/rx65n.ld            |  6 ++++++
 hal/rx72n.ld            |  6 ++++++
 include/user_settings.h |  3 +--
 5 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/arch.mk b/arch.mk
index 887e2dd7a..7668e0909 100644
--- a/arch.mk
+++ b/arch.mk
@@ -330,9 +330,6 @@ ifeq ($(ARCH),RENESAS_RX)
           ./lib/wolfssl/wolfcrypt/src/port/Renesas/renesas_common.o \
           ./lib/wolfssl/wolfcrypt/src/port/Renesas/renesas_tsip_util.o
 
-    # Key Data from Security Key Management Tool (SKMT). See docs/Renesas.md
-    OBJS+=./include/key_data.o
-
     # RX TSIP uses pre-compiled .a library by default
     ifeq ($(RX_TSIP_SRC),)
       ifeq ($(BIG_ENDIAN),1)
diff --git a/docs/Renesas.md b/docs/Renesas.md
index 7c0bcb29b..520a23215 100644
--- a/docs/Renesas.md
+++ b/docs/Renesas.md
@@ -69,7 +69,7 @@ Public key slot:       0
 Done.
 ```
 
-6) Create wrapped public key
+6) Create wrapped public key (code files)
 
 Use the Security Key Management Tool (SKMT) command line tool (CLI) to create a wrapped public key.
 
@@ -86,11 +86,25 @@ IV: 6C296A040EEF5EDD687E8D3D98D146D0
 Encrypted key: 5DD8D7E59E6AC85AE340BBA60AA8F8BE56C4C1FE02340C49EB8F36DA79B8D6640961FE9EAECDD6BADF083C5B6060C1D0309D28EFA25946F431979B9F9D21E77BDC5B1CC7165DE2F4AE51E418746260F518ED0C328BD3020DEC9B774DC00270B0CFBBE3DD738FDF715342CFBF2D461239
 ```
 
-7) Edit .config `PKA?=1`.
+7) Create wrapped public key (flash file)
 
-8) Rebuild wolfBoot. `make clean && make wolfboot.srec`
+Generate Motorola HEX file to write wrapped key to flash.
 
-9) Sign application
+```
+$ C:\Renesas\SecurityKeyManagementTool\cli\skmt.exe -genkey -ufpk file=./sample.key -wufpk file=./sample.key_enc.key -key file=./pub-ecc384.pem -mcu RX-TSIP -keytype secp384r1-public -output pub-ecc384.srec -filetype "mot" -address 0xFFFF0000
+```
+
+The generated file is a Motorola HEX (S-Record) formatted image containing the wrapped public key with instructions to use the `0xFFFF0000` address.
+
+The flash memory address `0xFFFF0000` must be set in two places:
+a) The `RENESAS_TSIP_INSTALLEDKEY_ADDR` macro in `user_settings.h`
+b) The linker script .rot section in `hal/rx72n.ld` or `hal/rx65n.ld`
+
+8) Edit .config `PKA?=1`.
+
+9) Rebuild wolfBoot. `make clean && make wolfboot.srec`
+
+10) Sign application
 
 Sign application using the created private key above `pri-ecc384.der`:
 
@@ -110,3 +124,7 @@ Calculating SHA256 digest...
 Signing the digest...
 Output image(s) successfully created.
 ```
+
+11) Flash wolfboot.srec, pub-ecc384.srec and signed application binary
+
+Download files to flash using Renesas flash programmer.
diff --git a/hal/rx65n.ld b/hal/rx65n.ld
index 562a3edea..74b6599ec 100644
--- a/hal/rx65n.ld
+++ b/hal/rx65n.ld
@@ -23,6 +23,12 @@ SECTIONS
         KEEP(*(.fvectors))
     } = 0x4
 
+    .rot 0xFFFF0000 :
+    {
+        /* Reserved space for Wrapped Public Key (See docs/Renesas.md) */
+        KEEP(*(.rot))
+    } = 0x2000 /* 8KB (min sector size) */
+
     .rvectors ORIGIN(ROM) :
     {
         _rvectors_start = .;
diff --git a/hal/rx72n.ld b/hal/rx72n.ld
index 09833cfc6..6e632c01a 100644
--- a/hal/rx72n.ld
+++ b/hal/rx72n.ld
@@ -22,6 +22,12 @@ SECTIONS
         KEEP(*(.fvectors))
     } = 0x4
 
+    .rot 0xFFFF0000 :
+    {
+        /* Reserved space for Wrapped Public Key (See docs/Renesas.md) */
+        KEEP(*(.rot))
+    } = 0x2000 /* 8KB (min sector size) */
+
     .rvectors ORIGIN(ROM) :
     {
         _rvectors_start = .;
diff --git a/include/user_settings.h b/include/user_settings.h
index 7504105f5..712b54ce4 100755
--- a/include/user_settings.h
+++ b/include/user_settings.h
@@ -444,8 +444,7 @@ extern int tolower(int c);
         #define WOLFSSL_RENESAS_TSIP_CRYPT
         #define WOLFSSL_RENESAS_TSIP_CRYPTONLY
         #define NO_WOLFSSL_RENESAS_TSIP_CRYPT_HASH
-        /* from key_data.h */
-        #define RENESAS_TSIP_INSTALLEDKEY_ADDR (&g_enc_pub_key)
+        #define RENESAS_TSIP_INSTALLEDKEY_ADDR 0xFFFF0000
         #define ENCRYPTED_KEY_BYTE_SIZE ENC_PUB_KEY_SIZE
         #define RENESAS_DEVID 7890
     #endif