What is Qualcomm Loader MBN vs ELF?

Qualcomm Loader MBN vs ELF

Qualcomm loaders play an important role in flashing Qualcomm-powered devices. Included among these are prog_emmc_firehose_8976_lite, prog_emmc_firehose_8976_ddr, prog_ufs_firehose_8996_lite, prog_ufs_firehose_sdm845_ddr, and prog_firehose_ddr_fwupdate, among many others, which execute different functions in firmware management. These differences should be taken into consideration by technicians and a service center.

Differences Between Loaders

The fundamental difference between the following variants of these loaders is DDR vs. Lite: DDR Loaders: These include DDR initialization that further enables the system to access memory at higher speeds. They also support a wider array of functionalities as well. They are also made to handle much more complicated activities; this in effect makes them very versatile and quick.

Lite Loaders: These versions are only of the SRAM utilization and therefore have limited functionality; they are less complex and usually applied in low-demanding situations.

In the general sense, DDR loaders are much more extensive and complex than their Lite versions, which use passive commands and almost no capabilities at all.

Target Group

These loaders envisioned here are targeted mostly at main service centers or in-service support, rather than at individual end-users or other third-party technicians. Their complexity and specialty functions run them out of the general consumer's league.

File formats: MBN & ELF

Working with Qualcomm Firmware usually deals with two major file formats:

MBN: Modem Binary or Multi Boot Image: MBN files are 32-bit files in an older format. When opened in a hex editor such as HXD, they start with the header:

#define MBN_HEAD_CODEWORD 0x844bdcd1 /* little-endian */

- ELF (Executable and Linkable Format):

For binary files, the start header of ELF files is `0x464C457F`.

Both can be a format required for the flashing processes that could be supported by the Qualcomm Flash Image Loader, more commonly called QFIL.

Firehose Firmware Update Files

Firehose firmware update files play an important role in some procedures involving Qualcomm devices. The Update FFU option, available in the source eMMCDL is not available on every loader. Executing it via a regular loader mostly results in failure.

These files are only triggered through IC Firmware Update and Patch commands. These have become increasingly relevant in the case of modern devices such as Oppo and Realme. The method here is to write and format using Patch commands and not standard commands since reading is restricted on loaders. This further uses SRAM, slower compared to DRAM (DDR).