CPU¶
CPUID to arch: https://github.com/mer-tools/oprofile/blob/master/libop/op_hw_specific.h#L119
CPU flags meaning: http://unix.stackexchange.com/questions/43539/what-do-the-flags-in-proc-cpuinfo-mean
Endianness¶
https://www.cs.umd.edu/class/sum2003/cmsc311/Notes/Data/endian.html
In big endian, you store the most significant byte(MSB) in the smallest address.
In little endian, you store the least significant byte(LSB) in the smallest address
Protection ring¶
UEFI Shell¶
https://software.intel.com/en-us/articles/uefi-shell
map # list disks
help bcfg
Buses¶
VESA (Video Electronics Standards Association)
https://en.wikipedia.org/wiki/List_of_device_bit_rates
|Technology|Rate||Year| |—|—|—| |ISA 16-Bit/8.33 MHz|66.7 Mbit/s|8.33 MB/s|1984 (created)| |I²C|3.4 Mbit/s|425 kB/s|1992 (standardized)| |Low Pin Count|125 Mbit/s|15.63 MB/s [x]|2002| |HyperTransport 3.1 (3.2 GHz, 32-pair)|409.6 Gbit/s|51.2 GB/s|2008| |Unified Media Interface 2.0 (UMI 2.0; ×4 link)|20 Gbit/s|2 GB/s [z]|2012| |Direct Media Interface 3.0 (DMI 3.0; ×4 link)|40 Gbit/s|4 GB/s [z]|2015| |AGP 8×|17.066 Gbit/s|2.133 GB/s|2002| |AGP 8× 64-bit|34.133 Gbit/s|4.266 GB/s|| |PCI 32-bit/66 MHz|2.133 Gbit/s|266.7 MB/s|1995| |PCI 64-bit/100 MHz|6.4 Gbit/s|800 MB/s|| |PCI-X QDR|34.133 Gbit/s|4.266 GB/s|| |PCI Express 2.0 (×32 link)[43]|160 Gbit/s|16 GB/s [z]|2007| |PCI Express 3.0 (×32 link)[44]|256 Gbit/s|31.51 GB/s [y]|2011| |QPI (9.6GT/s, 4.8 GHz)|307.2 Gbit/s|38.4 GB/s|2014|
https://en.wikipedia.org/wiki/NVLink
Infini Band¶
https://en.wikipedia.org/wiki/InfiniBand
| SDR | DDR | QDR | FDR10 | FDR | EDR | HDR | NDR | XDR | |
|---|---|---|---|---|---|---|---|---|---|
| Signaling rate (Gbit/s) | 2.5 | 5 | 10 | 10.3125 | 14.0625[6] | 25.78125 | 50 | 100 | 250 |
| Theoretical effective throughput, Gbs, per 1x[7] | 2 | 4 | 8 | 10 | 13.64 | 25 | 50 | ||
| Speeds for 12x links (Gbit/s) | 24 | 48 | 96 | 120 | 163.64 | 300 | 600 | ||
| Encoding (bits) | 8/10 | 8/10 | 8/10 | 64/66 | 64/66 | 64/66 | 64/66 | ||
| Adapter latency (microseconds)[8] | 5 | 2.5 | 1.3 | 0.7 | 0.7 | 0.5 | |||
| Year[9] | 2001,2003 | 2005 | 2007 | 2011 | 2011 | 2014[7] | 2017[7] | after 2020 | future |
Raspberry PI¶
/opt/vc/bin/vcgencmd measure_temp
Console¶
/dev/ttyAMA0
Speed (baud rate): 115200
Bits: 8
Parity: None
Stop Bits: 1
Flow Control: None
Resolution¶
SQCIF = 128x96
QCIF = 176x144
QVGA = 320x240
CIF = 352x240/288
HVGA = 640x240
VGA = 640x480
2 CIF = 704x240/288
4 CIF = 704x480/576
D1 CROPPED = 704x480/576
D1 = 720x480/576
D1 (525) 720 x 480 is in NTSC
D1 (625) 720 x 576 is in PAL
720p is 1280 x 720. (921,600 total pixels)
1080p is 1920x1080. (2,073,600 total pixels)
3MP is 2048 x 1536. (3,145,728 total pixels)
5MP is 2560 x 1920. (4,915,200 total pixels)
Screen¶
| Name | Wiki |
|---|---|
| OLED | https://en.wikipedia.org/wiki/OLED |
| microLED, micro-LED, mLED or μLED | https://en.wikipedia.org/wiki/MicroLED |
| Mini LED | https://en.wikipedia.org/wiki/LED-backlit_LCD#Mini_LED |