RFC Implement "fastboot flash" for eMMC

Hi Steve,

Quoted 168 lines · Marek Vasut

Quoted 30 lines · Lukasz Majewski

Quoted 23 lines

Hi Steve,

Quoted 13 lines

This series implements the "fastboot flash" command for eMMC devices. It supports both raw and sparse images.

NOTES:
- the support for the "fastboot flash" command is enabled with CONFIG_FASTBOOT_FLASH
- the support for eMMC is enabled with CONFIG_FASTBOOT_FLASH_MMC_DEV
- (future) the support for NAND would be enabled with CONFIG_FASTBOOT_FLASH_NAND(???)
- thus the proposal is to place the code in common/fb_mmc.c and (future) common/fb_nand.c(???), however, this may not be the appropriate location....

Would you consider another approach for providing flashing backend for fastboot?

I'd like to propose reusing of the dfu flashing code for this purpose. Such approach has been used successfully with USB "thor" downloading function.

Quoted 5 lines

Since the "fastboot" is using gadget infrastructure (thanks to the effort of Rob Herring) I think that it would be feasible to reuse the same approach as "thor" does. In this way the low level code would be kept in one place and we could refine and test it more thoroughly.

Quoted 9 lines

I'm all for this approach as well if possible.

Best regards,
Marek Vasut
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I have briefly investigated this suggestion....
And have 'hacked' some code as follows:

fb_mmc.c_001 renamed from fb_mmc.c_000 +1 -0

   		while (remaining_chunks) {
   			switch (le16_to_cpu(c_header->chunk_type)) {
   			case CHUNK_TYPE_RAW:
+#if 0
   				blkcnt =
   				    (le32_to_cpu(c_header->chunk_sz)

* blk_sz) / info.blksz;
   				buffer =
   				    (void *)c_header +
   				    le16_to_cpu(s_header->chunk_hdr_sz);

   				blks =
mmc_dev->block_write(mmc_dev->dev, blk, blkcnt, buffer);
   				if (blks != blkcnt) {
   					printf("Write failed
%lu\n", blks); strcpy(response,
   					       "FAILmmc write
failure"); return;
   				}

   				bytes_written += blkcnt *

info.blksz; +#else

fb_mmc.c_001 renamed from fb_mmc.c_000 +3 -0

+				buffer =
+				    (void *)c_header +
+

le16_to_cpu(s_header->chunk_hdr_sz); +

fb_mmc.c_001 renamed from fb_mmc.c_000 +1 -0

+				len =

le32_to_cpu(c_header->chunk_sz) * blk_sz;

fb_mmc.c_001 renamed from fb_mmc.c_000 +1 -0

+				ret_dfu = dfu_write_medium_mmc(dfu,

offset,
+
buffer, &len);

fb_mmc.c_001 renamed from fb_mmc.c_000 +2 -0

+				if (ret_dfu) {
+					printf("Write failed %lu\n",

len);

fb_mmc.c_001 renamed from fb_mmc.c_000 +2 -0

+					strcpy(response,
+					       "FAILmmc write

failure");

fb_mmc.c_001 renamed from fb_mmc.c_000 +6 -0

+					return;
+				}
+
+
+				bytes_written += len;
+#endif
   				break;
 
   			case CHUNK_TYPE_FILL:
   			case CHUNK_TYPE_DONT_CARE:
   			case CHUNK_TYPE_CRC32:
   				/* do nothing */
   				break;
 
   			default:
   				/* error */
   				printf("Unknown chunk type\n");
   				strcpy(response,
   				       "FAILunknown chunk type in

sparse image"); return;
   			}

+#if 0
blk += (le32_to_cpu(c_header->chunk_sz) *
blk_sz) / info.blksz;

fb_mmc.c_001 renamed from fb_mmc.c_000 +2 -0

+#else
+			offset += le32_to_cpu(c_header->chunk_sz) *

blk_sz; +#endif
c_header = (chunk_header_t *)((void

*)c_header + le32_to_cpu(c_header->total_sz));
   			remaining_chunks--;
   		}

fb_mmc.c_001 renamed from fb_mmc.c_000 +1 -0

   		/* raw image */
 
+#if 0
   		/* determine number of blocks to write */
   		blkcnt =
   		    ((download_bytes + (info.blksz - 1)) &

~(info.blksz - 1)); blkcnt = blkcnt / info.blksz;

if (blkcnt > info.size) {
printf("%s: too large for partition:
'%s'\n", __func__, cmd);
strcpy(response, "FAILtoo large for

partition"); return;
   		}

   		printf("Flashing Raw Image\n");

   		blks = mmc_dev->block_write(mmc_dev->dev,

info.start, blkcnt, download_buffer);
if (blks != blkcnt) {
printf("%s: failed writing to mmc device
%d\n", __func__, mmc_dev->dev);
strcpy(response, "FAILfailed writing to mmc

device"); return;
   		}

   		printf("........ wrote %lu bytes to '%s'\n",
   		       blkcnt * info.blksz, cmd);

fb_mmc.c_001 renamed from fb_mmc.c_000 +4 -0

+#else
+		printf("Flashing Raw Image\n");
+
+		ret_dfu = dfu_write_medium_mmc(dfu, offset,

download_buffer, &len);

fb_mmc.c_001 renamed from fb_mmc.c_000 +2 -0

+		if (ret_dfu) {
+			printf("%s: failed writing to mmc device

%d\n",

fb_mmc.c_001 renamed from fb_mmc.c_000 +2 -0

+			       __func__, mmc_dev->dev);
+			strcpy(response, "FAILfailed writing to mmc

device");

fb_mmc.c_001 renamed from fb_mmc.c_000 +4 -0

+			return;
+		}
+
+		printf("........ wrote %lu bytes to '%s'\n", len,

cmd); +#endif
}

Quoted 3 lines

NOTE:
- I know that I cannot call "dfu_write_medium_mmc()" directly -- but I just wanted to test this functionality

Indeed, it looks like an early proof-of-concept code :-).

Quoted 4 lines

My initial reaction is that using the DFU backend to effectively call the mmc block_write() function seems to cause an unnecessary amount of overhead;

It also allows to access/write data to other media - like NAND memory.

Quoted 6 lines

and the only thing that it really provides is a proven method of calculating the "number of blocks to write"...

I would be more interested in this backend if it would provide:
- handling of the "sparse image format"
-- would a CONFIG option to include this in the DFU_OP_WRITE

You are welcome to prepare patch which adds such functionality. Moreover, in the u-boot-dfu repository (master branch) you can find initial version of the regression tests for DFU. Extending the current one, or adding your own would be awesome :-)

Quoted 4 lines

case of the "mmc_block_op()" be acceptable?
- a method which uses "get_partition_info_efi_by_name()"

	-- no ideas yet...

I'm looking forward for RFC.

Quoted 2 lines

If the consensus is to use this DFU backend, then I will continue is this direction.

That would be great.

Quoted 3 lines

Please advise,
Thanks, Steve