C function to decode the Revision: field of /proc/cpuinfo on the Raspberry Pi.

Known revisions

The file /proc/cpuinfo contains a line such as:-

Revision : 0003

Prior to Raspberry Pi 2

that holds the revision number of the Raspberry Pi. Known revisions (prior to the Raspberry Pi 2) are:

Revision	Model	PCB Rev	Memory	Manufacturer
0000
0001
0002	B	1	256 MB	Egoman
0003	B	1	256 MB	Egoman
0004	B	2	256 MB	Sony UK
0005	B	2	256 MB	Qisda
0006	B	2	256 MB	Egoman
0007	A	2	256 MB	Egoman
0008	A	2	256 MB	Sony UK
0009	A	2	256 MB	Qisda
000a
000b
000c
000d	B	2	512 MB	Egoman
000e	B	2	512 MB	Sony UK
000f	B	2	512 MB	Egoman
0010	B+	1	512 MB	Sony UK
0011	compute	1	512 MB	Sony UK
0012	A+	1	256 MB	Sony UK
0013	B+	1	512 MB	Embest
0014	compute	1	512 MB	Embest
0015	A+	1	256 MB	Embest
0015	A+	1	512 MB	Embest

If the Raspberry Pi has been over-volted (voiding the warranty) the revision number will have 100 at the front. e.g. 1000002.

Raspberry Pi 2 / Model Zero

With the release of the Raspberry Pi 2, there is a new encoding of the Revision field in /proc/cpuinfo. The bit fields are as follows

FEDC	BA98	7654	3210	FEDC	BA98	7654	3210
	HG	FEEE	DDDD	CCCC	BBBB	BBBB	AAAA
1098	7654	3210	9876	5432	1098	7654	3210

#	bits	contains	values
A	00-03	PCB Revision	(the pcb revision number)
B	04-11	Model name	(see table bellow)
C	12-15	Processor	BCM2835, BCM2836, BCM2837, BCM2711, BCM2712
D	16-19	Manufacturer	Sony UK, Egoman, Embest, Sony Japan, Embest, Stadium
E	20-22	Memory size	256 MB, 512 MB, 1 GB, 2 GB, 4 GB, 8 GB, 16 GB
F	23-23	encoded flag	(if set, revision is a bit field)
G	24-24	waranty bit	(if set, warranty void - Pre Pi2)
H	25-25	waranty bit	(if set, warranty void - Post Pi2)

Also, due to some early issues the warranty bit has been move from bit 24 to bit 25 of the revision number (i.e. 0x2000000).

#	Model Name
00	A
01	B
02	A+
03	B+
04	2B
05	Alpha
06	CM1
07	Unknown
08	3B
09	Zero
0A	CM3
0B	Unknown
0C	Zero W
0D	3B+
0E	3A+
0F	Unknown
10	CM3+
11	4B
12	Zero 2 W
13	400
14	CM4
15	CM4S
16	Unknown
17	5
18	CM5
19	500
1A	CM5 Lite
1B	CM0

Revision : A01041

A - PCB Revision - 1 (first revision)
B - Model Name - 4 (Model B Pi 2)
C - Processor - 1 (BCM2836)
D - Manufacturer - 0 (Sony UK)
E - Memory - 2 (1 GB)
F - Endcoded flag - 1 (encoded cpu info)

Revision : A21041

A - PCB Revision - 1 (first revision)
B - Model Name - 4 (Model B Pi 2)
C - Processor - 1 (BCM2836)
D - Manufacturer - 2 (Embest)
E - Memory - 2 (1 GB)
F - Endcoded flag - 1 (encoded cpu info)

Revision : 900092

A - PCB Revision - 2 (second revision)
B - Model Name - 9 (Model Zero)
C - Processor - 0 (BCM2835)
D - Manufacturer - 0 (Sony UK)
E - Memory - 1 (512 MB)
F - Endcoded flag - 1 (encoded cpu info)

Revision : A02082

A - PCB Revision - 2 (second revision)
B - Model Name - 8 (Model B Pi 3)
C - Processor - 2 (BCM2837)
D - Manufacturer - 0 (Sony UK)
E - Memory - 2 (1 GB)
F - Endcoded flag - 1 (encoded cpu info)

Revision : A52082

A - PCB Revision - 2 (second revision)
B - Model Name - 8 (Model B Pi 3)
C - Processor - 2 (BCM2837)
D - Manufacturer - 5 (Stadium)
E - Memory - 2 (1 GB)
F - Endcoded flag - 1 (encoded cpu info)

Revision : B03111

A - PCB Revision - 1 (first revision)
B - Model Name - 17 (Model B Pi 4)
C - Processor - 3 (BCM2711)
D - Manufacturer - 0 (Sony UK)
E - Memory - 3 (2 GB)
F - Endcoded flag - 1 (encoded cpu info)