From 8294d7fea560258cff04cea1192ee38900458bbb Mon Sep 17 00:00:00 2001
From: occheung <dc@m-labs.hk>
Date: Thu, 15 Jul 2021 15:59:18 +0800
Subject: [PATCH] bootloader: swap endianness

Signed-off-by: occheung <dc@m-labs.hk>
---
 artiq/firmware/bootloader/Makefile | 3 ++-
 artiq/firmware/bootloader/main.rs  | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/artiq/firmware/bootloader/Makefile b/artiq/firmware/bootloader/Makefile
index ee70ff22f..d5a34f5ba 100644
--- a/artiq/firmware/bootloader/Makefile
+++ b/artiq/firmware/bootloader/Makefile
@@ -14,4 +14,5 @@ bootloader.elf: $(RUSTOUT)/libbootloader.a
 
 %.bin: %.elf
 	$(objcopy) -O binary
-	$(MSCIMG) $@
+	$(MSCIMG) $@ --little
+	objcopy -I binary -O binary --reverse-bytes=4 $@
diff --git a/artiq/firmware/bootloader/main.rs b/artiq/firmware/bootloader/main.rs
index bb7030051..daa3a9be7 100644
--- a/artiq/firmware/bootloader/main.rs
+++ b/artiq/firmware/bootloader/main.rs
@@ -10,7 +10,7 @@ extern crate riscv;
 
 use core::{ptr, slice, convert::TryFrom};
 use crc::crc32;
-use byteorder::{ByteOrder, BigEndian};
+use byteorder::{ByteOrder, LittleEndian};
 use board_misoc::{ident, cache, sdram, config, boot, mem as board_mem};
 #[cfg(has_slave_fpga_cfg)]
 use board_misoc::slave_fpga;
@@ -157,8 +157,8 @@ fn flash_boot() {
     println!("Booting from flash...");
 
     let header = unsafe { slice::from_raw_parts(FIRMWARE, 8) };
-    let length = BigEndian::read_u32(&header[0..]) as usize;
-    let expected_crc = BigEndian::read_u32(&header[4..]);
+    let length = LittleEndian::read_u32(&header[0..]) as usize;
+    let expected_crc = LittleEndian::read_u32(&header[4..]);
 
     if length == 0 || length == 0xffffffff {
         println!("No firmware present");