From 470be69f873dc7b0c5c07fb892367e08a78c7bbd Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Fri, 30 Dec 2022 13:18:41 +0000
Subject: [PATCH] relocate main() to a single section so that it can be put at
 a fixed address

---
 crypto/chacha20/Makefile.cross  |  6 +++---
 crypto/chacha20/memmap          | 11 ++++++++++-
 crypto/chacha20/src/svp64test.c |  5 ++++-
 crypto/chacha20/src/xchacha20.c |  2 ++
 4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/crypto/chacha20/Makefile.cross b/crypto/chacha20/Makefile.cross
index 9ff32d29..fb79bb85 100755
--- a/crypto/chacha20/Makefile.cross
+++ b/crypto/chacha20/Makefile.cross
@@ -5,13 +5,13 @@ AS = $(CROSS)as
 CC = $(CROSS)gcc
 LD = $(CROSS)ld
 OBJCOPY = $(CROSS)objcopy
-CFLAGS = -O3 -Wall -Wextra
+CFLAGS = -O3 -Wall -Wextra -mno-vsx
 
 AFLAGS ?= -mpwr9
 
 SRCDIR = src
 
-SOURCES := $(SRCDIR)/xchacha20.c $(SRCDIR)/svp64test.c
+SOURCES := $(SRCDIR)/svp64test.c $(SRCDIR)/xchacha20.c 
 OBJECTS := $(SOURCES:$(SRCDIR)/%.c=$(SRCDIR)/%.o)
 
 OBJ = chacha20test.bin
@@ -19,7 +19,7 @@ OBJ = chacha20test.bin
 export DUMP = /tmp/out
 
 # commented for luke's convenience
-#export SILENCELOG = 1
+# export SILENCELOG = 1
 
 all: tests
 
diff --git a/crypto/chacha20/memmap b/crypto/chacha20/memmap
index 052ccb0c..da68813a 100644
--- a/crypto/chacha20/memmap
+++ b/crypto/chacha20/memmap
@@ -1,11 +1,20 @@
 
 MEMORY
 {
-    ram  : ORIGIN = 0x20000000, LENGTH = 512M
+    ram  : ORIGIN = 0x20001000, LENGTH = 512M
+    fixedaddr  : ORIGIN = 0x20000000, LENGTH = 0x1000
 }
 
+
 SECTIONS
 {
+    .fixedaddr :
+    {
+    . = ALIGN(4);
+    __fixedaddr_start__ = .;
+    *(.fixedaddr*)
+    __fixedaddr_end__ = .;
+    } > fixedaddr
    .text : { *(.text*) } > ram
    .bss  : { *(.text*) } > ram
 }
diff --git a/crypto/chacha20/src/svp64test.c b/crypto/chacha20/src/svp64test.c
index 88402b86..3e081137 100644
--- a/crypto/chacha20/src/svp64test.c
+++ b/crypto/chacha20/src/svp64test.c
@@ -75,6 +75,9 @@ int check_cpp(void){
 	return(0);
 }
 
-int main(void){
+#define LOCATE_FUNC  __attribute__((__section__(".fixedaddr")))
+
+int LOCATE_FUNC main(int argc, char **argv[]){
 	return check_cpp();
 }
+
diff --git a/crypto/chacha20/src/xchacha20.c b/crypto/chacha20/src/xchacha20.c
index 2b29f60b..aa9c9043 100644
--- a/crypto/chacha20/src/xchacha20.c
+++ b/crypto/chacha20/src/xchacha20.c
@@ -130,6 +130,8 @@ void xchacha_encrypt_bytes(XChaCha_ctx *ctx, const uint8_t *m, uint8_t *c, uint3
 	uint8_t tmp[64];
 	uint32_t i;
 
+    return;
+
 	if (!bytes) return;
 
 	j0 = ctx->input[0];
-- 
2.30.2