[AT&T HTC One (M9)] thoughtlesskyle:
Here is some info for devs, should be useful for some

shell@htc_himaulatt:/ $ cat /proc/emmc
cat /proc/emmc
dev: size erasesize name
mmcblk0p1: 00004000 00000200 "board_info"
mmcblk0p2: 00400000 00000200 "pg1fs"
mmcblk0p3: 00100000 00000200 "sbl1"
mmcblk0p4: 00100000 00000200 "pmic"
mmcblk0p5: 02800000 00000200 "dummy"
mmcblk0p6: 001f7c00 00000200 "reserve_1"
mmcblk0p7: 00040000 00000200 "mfg"
mmcblk0p8: 017afc00 00000200 "pg2fs"
mmcblk0p9: 00080000 00000200 "rpm"
mmcblk0p10: 00200000 00000200 "tz"
mmcblk0p11: 00018000 00000200 "sdi"
mmcblk0p12: 00200000 00000200 "hyp"
mmcblk0p13: 00100000 00000200 "aboot"
mmcblk0p14: 00a00000 00000200 "tool_diag"
mmcblk0p15: 00a00000 00000200 "sp1"
mmcblk0p16: 00100000 00000200 "ddr"
mmcblk0p17: 00100000 00000200 "rfg_0"
mmcblk0p18: 00100000 00000200 "rfg_1"
mmcblk0p19: 00100000 00000200 "rfg_2"
mmcblk0p20: 00100000 00000200 "rfg_3"
mmcblk0p21: 00100000 00000200 "rfg_4"
mmcblk0p22: 00100000 00000200 "rfg_5"
mmcblk0p23: 00100000 00000200 "rfg_6"
mmcblk0p24: 00100000 00000200 "rfg_7"
mmcblk0p25: 00180000 00000200 "fsg"
mmcblk0p26: 03b00400 00000200 "radio"
mmcblk0p27: 01400000 00000200 "adsp"
mmcblk0p28: 00000400 00000200 "limits"
mmcblk0p29: 004f7c00 00000200 "reserve_2"
mmcblk0p30: 01600000 00000200 "persist"
mmcblk0p31: 00a00000 00000200 "ramdump"
mmcblk0p32: 00100000 00000200 "misc"
mmcblk0p33: 00180000 00000200 "modem_st1"
mmcblk0p34: 00180000 00000200 "modem_st2"
mmcblk0p35: 01400000 00000200 "fataldevlog"
mmcblk0p36: 01e00000 00000200 "devlog"
mmcblk0p37: 00040000 00000200 "pdata"
mmcblk0p38: 00004000 00000200 "control"
mmcblk0p39: 00010000 00000200 "extra"
mmcblk0p40: 00100000 00000200 "cdma_record"
mmcblk0p41: 00000400 00000200 "fsc"
mmcblk0p42: 00002000 00000200 "ssd"
mmcblk0p43: 00080000 00000200 "sensor_hub"
mmcblk0p44: 00020000 00000200 "sec"
mmcblk0p45: 00100000 00000200 "abootbak"
mmcblk0p46: 00002800 00000200 "cir_img"
mmcblk0p47: 00140400 00000200 "local"
mmcblk0p48: 00080000 00000200 "frp"
mmcblk0p49: 00200000 00000200 "cpe"
mmcblk0p50: 01400000 00000200 "carrier"
mmcblk0p51: 00040000 00000200 "skylink"
mmcblk0p52: 00020000 00000200 "rfg_8"
mmcblk0p53: 00020000 00000200 "rfg_9"
mmcblk0p54: 00020000 00000200 "rfg_10"
mmcblk0p55: 00020000 00000200 "rfg_11"
mmcblk0p56: 00020000 00000200 "rfg_12"
mmcblk0p57: 00020000 00000200 "rfg_13"
mmcblk0p58: 00020000 00000200 "rfg_14"
mmcblk0p59: 00020000 00000200 "rfg_15"
mmcblk0p60: 01000000 00000200 "absolute"
mmcblk0p61: 00e07000 00000200 "reserve"
mmcblk0p62: 04000000 00000200 "hosd"
mmcblk0p63: 04000000 00000200 "boot"
mmcblk0p64: 04000000 00000200 "recovery"
mmcblk0p65: 14000000 00000200 "cache"
mmcblk0p66: 18000000 00000200 "system"
mmcblk0p67: e0000000 00000200 "userdata"
mmcblk0p68: 12200000 00000200 "apppreload"
mmcblk0p69: 03c00000 00000200 "cota"
mmcblk0p70: 00a00000 00000200 "battery"

shell@htc_himaulatt:/ $ cat /proc/partitions ls -la /dev/block/platform/dw_mmc/
y-name
at /proc/partitions ls -la /dev/block/platform/dw_mmc/by-name <
major minor #blocks name

179 0 30535680 mmcblk0
179 1 16 mmcblk0p1
179 2 4096 mmcblk0p2
179 3 1024 mmcblk0p3
179 4 1024 mmcblk0p4
179 5 40960 mmcblk0p5
179 6 2015 mmcblk0p6
179 7 256 mmcblk0p7
179 8 24255 mmcblk0p8
179 9 512 mmcblk0p9
179 10 2048 mmcblk0p10
179 11 96 mmcblk0p11
179 12 2048 mmcblk0p12
179 13 1024 mmcblk0p13
179 14 10240 mmcblk0p14
179 15 10240 mmcblk0p15
259 0 1024 mmcblk0p16
259 1 1024 mmcblk0p17
259 2 1024 mmcblk0p18
259 3 1024 mmcblk0p19
259 4 1024 mmcblk0p20
259 5 1024 mmcblk0p21
259 6 1024 mmcblk0p22
259 7 1024 mmcblk0p23
259 8 1024 mmcblk0p24
259 9 1536 mmcblk0p25
259 10 60417 mmcblk0p26
259 11 20480 mmcblk0p27
259 12 1 mmcblk0p28
259 13 5087 mmcblk0p29
259 14 22528 mmcblk0p30
259 15 10240 mmcblk0p31
259 16 1024 mmcblk0p32
259 17 1536 mmcblk0p33
259 18 1536 mmcblk0p34
259 19 20480 mmcblk0p35
259 20 30720 mmcblk0p36
259 21 256 mmcblk0p37
259 22 16 mmcblk0p38
259 23 64 mmcblk0p39
259 24 1024 mmcblk0p40
259 25 1 mmcblk0p41
259 26 8 mmcblk0p42
259 27 512 mmcblk0p43
259 28 128 mmcblk0p44
259 29 1024 mmcblk0p45
259 30 10 mmcblk0p46
259 31 1281 mmcblk0p47
259 32 512 mmcblk0p48
259 33 2048 mmcblk0p49
259 34 20480 mmcblk0p50
259 35 256 mmcblk0p51
259 36 128 mmcblk0p52
259 37 128 mmcblk0p53
259 38 128 mmcblk0p54
259 39 128 mmcblk0p55
259 40 128 mmcblk0p56
259 41 128 mmcblk0p57
259 42 128 mmcblk0p58
259 43 128 mmcblk0p59
259 44 16384 mmcblk0p60
259 45 14364 mmcblk0p61
259 46 65536 mmcblk0p62
259 47 65536 mmcblk0p63
259 48 65536 mmcblk0p64
259 49 327680 mmcblk0p65
259 50 4587520 mmcblk0p66
259 51 24641536 mmcblk0p67
259 52 296960 mmcblk0p68
259 53 61440 mmcblk0p69
259 54 10240 mmcblk0p70
179 16 4096 mmcblk0rpmb

Stock AT&T System and Boot.img Dump