[EFR32] OTA: Use word-aligned buffer in bootloader storage APIs

docs/guides/silabs_efr32_software_update.md

@@ -18,8 +18,12 @@ all of the EFR32 example applications.
  scripts/examples/gn_build_example.sh examples/ota-provider-app/linux out/debug chip_config_network_layer_ble=false
 
 - Build or download the Gecko Bootloader binary. Bootloader should be built
- with the Gecko SDK version 3.2.1 or earlier, type "external SPI" configured
- with a single slot of at least 1000 KB. Pre-built binaries should be
+ with the Gecko SDK version 3.2.1 or earlier. For the bootloader using the
+ external flash select the "external SPI" bootloader type configured with a
+ single slot of at least 1000 KB. For the bootloader using the internal flash
+ (supported on MG24 boards only) select the "internal storage" bootloader
+ type. Follow the instructions in "UG266: Silicon Labs Gecko Bootloader
+ User’s Guide". Pre-built binaries for some configurations should be
  available in
 
  third_party/efr32_sdk/repo/platform/bootloader/sample-apps/bootloader-storage-spiflash-single

src/platform/EFR32/OTAImageProcessorImpl.cpp

@@ -21,6 +21,7 @@
 
 extern "C" {
 #include "platform/bootloader/api/btl_interface.h"
+#include "platform/emlib/inc/em_bus.h" // For CORE_CRITICAL_SECTION
 }
 
 /// No error, operation OK
@@ -29,8 +30,10 @@ extern "C" {
 namespace chip {
 
 // Define static memebers
-uint8_t OTAImageProcessorImpl::mSlotId;
-uint32_t OTAImageProcessorImpl::mWriteOffset;
+uint8_t OTAImageProcessorImpl::mSlotId = 0;
+uint32_t OTAImageProcessorImpl::mWriteOffset = 0;
+uint16_t OTAImageProcessorImpl::writeBufOffset = 0;
+uint8_t OTAImageProcessorImpl::writeBuffer[kAlignmentBytes] __attribute__((aligned(4))) = { 0 };
 
 CHIP_ERROR OTAImageProcessorImpl::PrepareDownload()
 {
@@ -89,9 +92,13 @@ void OTAImageProcessorImpl::HandlePrepareDownload(intptr_t context)
  return;
  }
 
- bootloader_init();
- mSlotId = 0; // Single slot until we support multiple images
- mWriteOffset = 0;
+ ChipLogProgress(SoftwareUpdate, "HandlePrepareDownload");
+
+ CORE_CRITICAL_SECTION(bootloader_init();)
+ mSlotId = 0; // Single slot until we support multiple images
+ writeBufOffset = 0;
+ mWriteOffset = 0;
+ imageProcessor->mParams.downloadedBytes = 0;
 
  imageProcessor->mHeaderParser.Init();
 
@@ -102,12 +109,34 @@ void OTAImageProcessorImpl::HandlePrepareDownload(intptr_t context)
 
 void OTAImageProcessorImpl::HandleFinalize(intptr_t context)
 {
+ uint32_t err = SL_BOOTLOADER_OK;
  auto * imageProcessor = reinterpret_cast<OTAImageProcessorImpl *>(context);
  if (imageProcessor == nullptr)
  {
  return;
  }
 
+ // Pad the remainder of the write buffer with zeros and write it to bootloader storage
+ if (writeBufOffset != 0)
+ {
+ // Account for last bytes of the image not yet written to storage
+ imageProcessor->mParams.downloadedBytes += writeBufOffset;
+
+ while (writeBufOffset != kAlignmentBytes)
+ {
+ writeBuffer[writeBufOffset] = 0;
+ writeBufOffset++;
+ }
+
+ CORE_CRITICAL_SECTION(err = bootloader_eraseWriteStorage(mSlotId, mWriteOffset, writeBuffer, kAlignmentBytes);)
+ if (err)
+ {
+ ChipLogError(SoftwareUpdate, "ERROR: In HandleFinalize bootloader_eraseWriteStorage() error %ld", err);
+ imageProcessor->mDownloader->EndDownload(CHIP_ERROR_WRITE_FAILED);
+ return;
+ }
+ }
+
  imageProcessor->ReleaseBlock();
 
  ChipLogProgress(SoftwareUpdate, "OTA image downloaded successfully");
@@ -119,22 +148,23 @@ void OTAImageProcessorImpl::HandleApply(intptr_t context)
 
  ChipLogProgress(SoftwareUpdate, "OTAImageProcessorImpl::HandleApply()");
 
- err = bootloader_verifyImage(mSlotId, NULL);
+ CORE_CRITICAL_SECTION(err = bootloader_verifyImage(mSlotId, NULL);)
+
  if (err != SL_BOOTLOADER_OK)
  {
  ChipLogError(SoftwareUpdate, "ERROR: bootloader_verifyImage() error %ld", err);
  return;
  }
 
- err = bootloader_setImageToBootload(mSlotId);
+ CORE_CRITICAL_SECTION(err = bootloader_setImageToBootload(mSlotId);)
  if (err != SL_BOOTLOADER_OK)
  {
  ChipLogError(SoftwareUpdate, "ERROR: bootloader_setImageToBootload() error %ld", err);
  return;
  }
 
  // This reboots the device
- bootloader_rebootAndInstall();
+ CORE_CRITICAL_SECTION(bootloader_rebootAndInstall();)
 }
 
 void OTAImageProcessorImpl::HandleAbort(intptr_t context)
@@ -174,18 +204,30 @@ void OTAImageProcessorImpl::HandleProcessBlock(intptr_t context)
  return;
  }
 
- err = bootloader_eraseWriteStorage(mSlotId, mWriteOffset, (uint8_t *) (block.data()), block.size());
-
- if (err)
+ // Copy data into the word-aligned writeBuffer, once it fills write its contents to the bootloader storage
+ // Final data block is handled in HandleFinalize().
+ uint32_t blockReadOffset = 0;
+ while (blockReadOffset < block.size())
  {
- ChipLogError(SoftwareUpdate, "ERROR (possible wrong bootloader version): bootloader_eraseWriteStorage() error %ld", err);
-
- imageProcessor->mDownloader->EndDownload(CHIP_ERROR_WRITE_FAILED);
- return;
+ writeBuffer[writeBufOffset] = *((block.data()) + blockReadOffset);
+ writeBufOffset++;
+ blockReadOffset++;
+ if (writeBufOffset == kAlignmentBytes)
+ {
+ writeBufOffset = 0;
+
+ CORE_CRITICAL_SECTION(err = bootloader_eraseWriteStorage(mSlotId, mWriteOffset, writeBuffer, kAlignmentBytes);)
+ if (err)
+ {
+ ChipLogError(SoftwareUpdate, "ERROR: In HandleProcessBlock bootloader_eraseWriteStorage() error %ld", err);
+ imageProcessor->mDownloader->EndDownload(CHIP_ERROR_WRITE_FAILED);
+ return;
+ }
+ mWriteOffset += kAlignmentBytes;
+ imageProcessor->mParams.downloadedBytes += kAlignmentBytes;
+ }
  }
 
- mWriteOffset += block.size(); // Keep our own track of how far we've written
- imageProcessor->mParams.downloadedBytes += block.size();
  imageProcessor->mDownloader->FetchNextData();
 }
 

src/platform/EFR32/OTAImageProcessorImpl.h

@@ -61,12 +61,20 @@ class OTAImageProcessorImpl : public OTAImageProcessorInterface
  */
  CHIP_ERROR ReleaseBlock();
 
+ // EFR32 platform creates a single instance of OTAImageProcessorImpl class.
+ // If that changes then the use of static members and functions must be revisited
  static uint32_t mWriteOffset; // End of last written block
  static uint8_t mSlotId; // Bootloader storage slot
  MutableByteSpan mBlock;
  OTADownloader * mDownloader;
  OTAImageHeaderParser mHeaderParser;
- const char * mImageFile = nullptr;
+ const char * mImageFile = nullptr;
+ static constexpr size_t kAlignmentBytes = 64;
+ // Intermediate, word-aligned buffer for writing to the bootloader storage.
+ // Bootloader storage API requires the buffer size to be a multiple of 4.
+ static uint8_t writeBuffer[kAlignmentBytes] __attribute__((aligned(4)));
+ // Offset indicates how far the write buffer has been filled
+ static uint16_t writeBufOffset;
 };
 
 } // namespace chip