Hello, Elyes!
After "Convert to ASL 2.0 syntax" set of commits to current coreboot branch, i lost the data of battery current on BAT state from:
cat /sys/class/power_supply/BAT0/current_now  
0
On AC state (charging) data is present:
cat /sys/class/power_supply/BAT0/current_now 
1346000
Checkout to coreboot tag/4.13 is fixing the problem.
But system was very unstable with:
Apr  4 23:45:06 tp0 kernel: [   60.868922] BUG: unable to handle page fault for address: 000000ccfffffffc
Apr  4 23:45:06 tp0 kernel: [   60.868992] #PF: supervisor read access in kernel mode
Apr  4 23:45:06 tp0 kernel: [   60.869033] #PF: error_code(0x0000) - not-present page
Apr  4 23:45:06 tp0 kernel: [   60.869074] PGD 0 P4D 0  
Apr  4 23:45:06 tp0 kernel: [   60.869102] Oops: 0000 [#1] SMP PTI
Apr  4 23:45:06 tp0 kernel: [   60.869134] CPU: 0 PID: 1960 Comm: git Tainted: G     U            5.10.0-5-amd64 #1 Debian 5.10.24-1
Apr  4 23:45:06 tp0 kernel: [   60.869261] RIP: 0010:__d_lookup_rcu+0x82/0x170
System:
Lenovo T420
coreboot-4.13-2951-g0972871a23-T420
Debian bullseye/sid
Battery in main slot
 
Any ideas?