xbl xbl_config last_parti QFIL QPST
fdisk -l /dev/block/sdb
CN:/ # fdisk -l /dev/block/sdb
Note: sector size is 4096 (not 512)
Found valid GPT with protective MBR; using GPT
Disk /dev/block/sdb: 8192 sectors, 32.0M
Logical sector size: 4096
Disk identifier (GUID): 6231a3fe-971e-e980-9a6a-ed770c389cac
Partition table holds up to 32 entries
First usable sector is 6, last usable sector is 1018
Number Start (sector) End (sector) Size Name
1 6 901 3584K xbl
2 902 933 128K xbl_config
3 934 1018 340K last_parti
(in Qualcomm terms) the. eXtensible Boot Loader (XBL)
PBL（Primary Bootloader）将加载XBL（Secondary Bootloader）
https://en.wikipedia.org/wiki/Booting_process_of_Android_devices
由于引导 ROM 中的空间有限，因此使用 eMMC 或 eUFS 上的辅助引导加载程序。 [7] 辅助引导加载程序初始化 TrustZone。 [7] [8]
SBL 现在被高通称为 XBL，并使用 UEFI 交叉兼容，以便在第二阶段启动 Android 以外的操作系统。
https://blog.quarkslab.com/analysis-of-qualcomm-secure-boot-chains.html
last_parti
last_parti意思可能是空闲的没有用到的，因为cat /proc/partitions里只有sdb1和sdb2，没有sdb3
xxd
CN:/ # file /dev/block/sdb1
/dev/block/sdb1: block special
CN:/ # xxd /dev/block/sdb3 | head -10
xxd: /dev/block/sdb3: No such file or directory
CN:/ # xxd /dev/block/sdb2 | head -10
00000000: 7f45 4c46 0201 0100 0000 0000 0000 0000 .ELF............
00000010: 0200 2800 0100 0000 0000 8d14 0000 0000 ..(.............
00000020: 4000 0000 0000 0000 0000 0000 0000 0000 @...............
00000030: 0500 0000 4000 3800 0b00 0000 0000 0000 ....@.8.........
00000040: 0000 0000 0000 0007 0000 0000 0000 0000 ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000060: a802 0000 0000 0000 0000 0000 0000 0000 ................
00000070: 0000 0000 0000 0000 0000 0000 0000 2002 .............. .
00000080: 0010 0000 0000 0000 00a0 8e14 0000 0000 ................
00000090: 00a0 8e14 0000 0000 881a 0000 0000 0000 ................
hexedit
hexedit /dev/block/sdb2
不太好用，有的键不管用。比如说End: end of line 没法跳转到文件底部
Home: beginning of line
End: end of line
不管用
PUp: page forward
PDown: page backward
Ctrl+C - unconditional quit (without saving).
可以用
RMX1901CN:/ # hexedit
BusyBox v1.30.1-osm0sis (2019-02-28 17:35:07 AST) multi-call binary.
Usage: hexedit FILE
Edit FILE in hexadecimal
Qualcomm Product Support Tools (QPST)
Qualcomm Flash Image Loader (QFIL)
hexdump -s
RMX1901CN:/ # fdisk -l /dev/block/sde
Note: sector size is 4096 (not 512)
Found valid GPT with protective MBR; using GPT
Disk /dev/block/sde: 6815744 sectors, 2048M
Logical sector size: 4096
Disk identifier (GUID): e0d6e66a-40ea-9cbc-1e79-9fa744f514f3
Partition table holds up to 64 entries
First usable sector is 6, last usable sector is 851962
Number Start (sector) End (sector) Size Name
7 41862 42117 1024K abl
abl大小1024K 即1024000（1024*1024）
所以-s后边不能超过1024000
RMX1901CN:/ # hexdump -C -n 1000 -s 1000000 /dev/block/by-name/abl
000f4240 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000f4620
RMX1901CN:/ # hexdump -C -n 1000 -s 2000000 /dev/block/by-name/abl
hexdump: /dev/block/by-name/abl: Invalid argument
