- Aug 22, 2019
- 73
- 204
Boot Config for eMMC used in Samsung devices depends entirely on the type of processor on which the device is assembled:
1) Boot config: 0x 38 , 0x 00 , 0x 0x - used in devices with a Qualcomm processor ("Qualcomm 2" preset).
2) Boot config: 0x 48 , 0x 01 , 0x 00 - used in devices with an Exynos processor ("Exynos" preset).
3) Boot config: 0x 48 , 0x 00 , 0x 01- used in devices with MTK processor ("Mediatek" preset).
4) Boot config: 0x 08 , 0x 00 , 0x 00 - used in devices with a Spreadtrum processor ("Spreadtrum" preset).
BootConfig is also used for NVidia (Tegra) and Broadcom processors.
Features of using ROM2 / ROM3 / RPMB in eMMC in Samsung devices:
1) The ROM2 eMMC section in Samsung devices is used for Boot recording (all types of processors except Qualcomm, Broadcom).
2) The ROM3 eMMC section in Samsung devices is very rarely used (with NVidia (Tegra) processors).
3) ROM2 / 3 dimensions are critical only for NVidia (Tegra) processors (must match the original ones). For the rest of the time they do not have to be very small (at least 1-2MB), so there instead of the firmware files.
4) The RPMB partition is used in devices with Exynos processor, so when replacing eMMC in devices with Exynos processor, the state of the RPMB partition should be Clean . Otherwise, at startup, the device will fall into the Download mode with the inscription Invalid RPMB Data .
No information is currently known about the size requirements for the RPMB partition .
EMMC markup types:MBR, GPT The
peculiarities of working with markup in Samsung devices is that to describe partitions, in addition to MBR , GPT , a special PIT file (saved in eMMC) is additionally used . This file is used to markup and match the location of the firmware files in the eMMC partitions.
Features of recovering Boot files in Samsung devices:
1) Samsung devices use protection against downgrading the bootloader version ( Boot ). The bootloader version is indicated in the firmware name (example: A720FXXU 5 CRH3 ).
Therefore, the restoration of Samsung brand devices must be done with confidence that the used binary dumps from the firmware have the same or higher Boot version . Or use the "Write by vendor" - "Samsung" mode described below.
2) For correct recovery of Boot files in eMMC in Samsung devices, you need to write to eMMC in the "Write by vendor" - "Samsung" mode at least the contents of BL _ *. Tar files from 4/5 file firmware, and sometimes the "preload "(it contains graphics for Download mode). Recording can be done via ISP mode (it is desirable to use HiPower CLK mode),
3) Restoring Boot using the "Write by vendor" - "Samsung" mode should be done with the "Re partition" checkbox unchecked , if there is a valid GPT ( MBR ) in the device (inscription: GPT header is found and is valid in the log window).
