From 1259f8d776a49f5daf1dbb3aff0c3643e377e8e0 Mon Sep 17 00:00:00 2001
From: Bernd Meyer <bmeyer@dius.com.au>
Date: Tue, 4 Aug 2015 12:59:59 +1000
Subject: [PATCH] Deal with unaligned destination parameter to flash read

(Occurs e.g. when SPIFFS cache is disabled.)

Implementation mirrors the existing handling in the write path.
---
 app/platform/common.c   |  2 +-
 app/platform/platform.c | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/app/platform/common.c b/app/platform/common.c
index 711a8a4a..617f6831 100644
--- a/app/platform/common.c
+++ b/app/platform/common.c
@@ -220,7 +220,7 @@ uint32_t platform_flash_read( void *to, uint32_t fromaddr, uint32_t size )
 #else // #ifindef INTERNAL_FLASH_READ_UNIT_SIZE
   uint32_t temp, rest, ssize = size;
   unsigned i;
-  char tmpdata[ INTERNAL_FLASH_READ_UNIT_SIZE ];
+  char tmpdata[ INTERNAL_FLASH_READ_UNIT_SIZE ] __attribute__ ((aligned(INTERNAL_FLASH_READ_UNIT_SIZE)));
   uint8_t *pto = ( uint8_t* )to;
   const uint32_t blksize = INTERNAL_FLASH_READ_UNIT_SIZE;
   const uint32_t blkmask = INTERNAL_FLASH_READ_UNIT_SIZE - 1;
diff --git a/app/platform/platform.c b/app/platform/platform.c
index 40aa50ad..6ed88d18 100644
--- a/app/platform/platform.c
+++ b/app/platform/platform.c
@@ -460,6 +460,11 @@ spi_data_type platform_spi_send_recv( unsigned id, spi_data_type data )
 // ****************************************************************************
 // Flash access functions
 
+/*
+ * Assumptions:
+ * > toaddr is INTERNAL_FLASH_WRITE_UNIT_SIZE aligned
+ * > size is a multiple of INTERNAL_FLASH_WRITE_UNIT_SIZE
+ */
 uint32_t platform_s_flash_write( const void *from, uint32_t toaddr, uint32_t size )
 {
   toaddr -= INTERNAL_FLASH_START_ADDRESS;
@@ -484,12 +489,37 @@ uint32_t platform_s_flash_write( const void *from, uint32_t toaddr, uint32_t siz
   }
 }
 
+/*
+ * Assumptions:
+ * > fromaddr is INTERNAL_FLASH_READ_UNIT_SIZE aligned
+ * > size is a multiple of INTERNAL_FLASH_READ_UNIT_SIZE
+ */
 uint32_t platform_s_flash_read( void *to, uint32_t fromaddr, uint32_t size )
 {
+  if (size==0)
+    return 0;
+
   fromaddr -= INTERNAL_FLASH_START_ADDRESS;
   SpiFlashOpResult r;
   WRITE_PERI_REG(0x60000914, 0x73);
-  r = flash_read(fromaddr, (uint32 *)to, size);
+
+  const uint32_t blkmask = (INTERNAL_FLASH_READ_UNIT_SIZE - 1);
+  if( ((uint32_t)to) & blkmask )
+  {
+    uint32_t size2=size-INTERNAL_FLASH_READ_UNIT_SIZE;
+    uint32* to2=(uint32*)((((uint32_t)to)&(~blkmask))+INTERNAL_FLASH_READ_UNIT_SIZE);
+    r = flash_read(fromaddr, to2, size2);
+    if(SPI_FLASH_RESULT_OK == r)
+    {
+      os_memmove(to,to2,size2);
+      char back[ INTERNAL_FLASH_READ_UNIT_SIZE ] __attribute__ ((aligned(INTERNAL_FLASH_READ_UNIT_SIZE)));
+      r=flash_read(fromaddr+size2,(uint32*)back,INTERNAL_FLASH_READ_UNIT_SIZE);
+      os_memcpy((uint8_t*)to+size2,back,INTERNAL_FLASH_READ_UNIT_SIZE);
+    }
+  }
+  else
+    r = flash_read(fromaddr, (uint32 *)to, size);
+
   if(SPI_FLASH_RESULT_OK == r)
     return size;
   else{