Cdtjkyj

I recently acquired an Asus Chromebook C201, which I am in the process of installing Linux on. I have installed Arch on an SD card, which is booting fine; however, the output of lsblk is different between that and Chrome OS, and I am wondering what some of the devices are (the systems are using different kernels).

This is the output of lsblk from Chrome OS:

$ lsblk

NAME          MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT

loop0           7:0    0   3.1G  0 loop 

`-encstateful 254:1    0   3.1G  0 dm   /mnt/stateful_partition/encrypted

loop1           7:1    0     2G  0 loop /run/cryptohome/ephemeral_mount/a9187bc0905bb69ac2f5215eefdc11b0c6d76c02

mmcblk1       179:0    0 119.1G  0 disk 

|-mmcblk1p1   179:1    0    16M  0 part 

`-mmcblk1p2   179:2    0 119.1G  0 part /media/removable/SD Card

mmcblk0       179:16   0  14.7G  0 disk 

|-mmcblk0p1   179:17   0  10.5G  0 part /mnt/stateful_partition

|-mmcblk0p2   179:18   0    16M  0 part 

|-mmcblk0p3   179:19   0     2G  0 part 

|-mmcblk0p4   179:20   0    16M  0 part 

|-mmcblk0p5   179:21   0     2G  0 part 

|-mmcblk0p6   179:22       512B  0 part 

|-mmcblk0p7   179:23       512B  0 part 

|-mmcblk0p8   179:24        16M  0 part /usr/share/oem

|-mmcblk0p9   179:25       512B  0 part 

|-mmcblk0p10  179:26       512B  0 part 

|-mmcblk0p11  179:27         8M  0 part 

`-mmcblk0p12  179:28        16M  0 part 

mmcblk0boot0  179:32   0     4M  1 disk 

mmcblk0boot1  179:48   0     4M  1 disk 

mmcblk0rpmb   179:64   0     4M  0 disk 

zram0         253:0    0   3.8G  0 disk [SWAP]

and this is the output from Arch:

$ lsblk

NAME         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT

mtdblock0     31:0    0     4M  0 disk 

mmcblk2      179:0    0  14.7G  0 disk 

mmcblk2boot0 179:16   0     4M  1 disk 

mmcblk2boot1 179:32   0     4M  1 disk 

mmcblk0      179:48   0 119.1G  0 disk 

├─mmcblk0p1  179:49   0    16M  0 part 

└─mmcblk0p2  179:50   0 119.1G  0 part /

Clearly, the mmcblk0/1/2 are the SD card and the built-in eMMC flash. However, I am curious as to what the mmcblk0boot0/mmcblk0boot1 devices are. The names and the fact they are read-only suggest they might be part of the boot ROM that is being made available as block devices. Is that the case?

Another thing is that Chrome OS is showing mmcblk0rpmb, which isn't present in the Arch output. However, that one is showing a different device, mtdblock0. These look like they are possibly(?) the same device, as the size is the same. What are these, and why do they have different major numbers with the two different kernels?

Another thing that is puzzling me is that the Chrome OS doesn't seem to have any partition mounted as root (/). How can that be the case, yet the system is booted and I have access to the filesystem?

(I know what the loop and zram devices are)