Tuesday 28 February 2023
Here is how you can detect if you’ve booted your computer using a UEFI BIOS or a Legacy BIOS. First, install the dmidecode utility from your operating system repository. On Debian, you can:
1apt-get install dmidecode
dmidecode reports information related to the BIOS under a type 0 entry. A quick way to detect the BIOS mode is:
1sudo dmidecode -t 0 | grep UEFI > /dev/null && echo UEFI || echo BIOS
On a (Legacy) BIOS system you would see:
1$ sudo dmidecode -t 0
2# dmidecode 3.4
3Getting SMBIOS data from sysfs.
4SMBIOS 3.0.0 present.
5
6Handle 0x0000, DMI type 0, 26 bytes
7BIOS Information
8 Vendor: 3mdeb
9 Version: Dasharo (coreboot+SeaBIOS)
10 Release Date: 08/23/2022
11 ROM Size: 12 MB
12 Characteristics:
13 PCI is supported
14 PC Card (PCMCIA) is supported
15 BIOS is upgradeable
16 Selectable boot is supported
17 ACPI is supported
18 Targeted content distribution is supported
19 BIOS Revision: 0.0
20 Firmware Revision: 0.0
On a UEFI system you would see:
1$ sudo dmidecode -t 0
2# dmidecode 3.4
3Getting SMBIOS data from sysfs.
4SMBIOS 3.1.1 present.
5
6Handle 0x0000, DMI type 0, 26 bytes
7BIOS Information
8 Vendor: American Megatrends Inc.
9 Version: 2202
10 Release Date: 07/14/2020
11 Address: 0xF0000
12 Runtime Size: 64 kB
13 ROM Size: 16 MB
14 Characteristics:
15 PCI is supported
16 APM is supported
17 BIOS is upgradeable
18 BIOS shadowing is allowed
19 Boot from CD is supported
20 Selectable boot is supported
21 BIOS ROM is socketed
22 EDD is supported
23 Print screen service is supported (int 5h)
24 8042 keyboard services are supported (int 9h)
25 Serial services are supported (int 14h)
26 Printer services are supported (int 17h)
27 ACPI is supported
28 USB legacy is supported
29 BIOS boot specification is supported
30 Targeted content distribution is supported
31 UEFI is supported
32 BIOS Revision: 5.13
#uefi #seabios #coreboot #bios 👢