IMPI to Redfish

• IPMI (Intelligent Platform Management Interface)
  
• https://www.intel.com/content/www/us/en/products/docs/servers/ipmi/ipmi-home.html
• 여러 대의 computer로 구성되는 server system 의 관리에 있어, 각 computer의 구성 정보를 기술하고, 동작 상태를 확인하거나 변경할 수 있는 방안을 표준화 한 것.
• 더 이상 활동하지 않고, Redfish와 같은 더 많은 기능이 있는 최신 interface 의 채택을 권유.
  
• Redfish
  
• https://redfish.dmtf.org/
  
• https://youtu.be/nBCjuuOjxRQ?si=4iZHN2sqltDHV17F
• 각 정보는 JSON 형식으로 기술되며, REST protocol 로 통신.
  
• JSON (Java Script Object Notation) : Javascript 에서 유래된 key/value 쌍 형태의 표준화 된 정보 기술 방법.
• REST (REpresentational State Transfer) : HTTP 기반 표준 통신 방안.

Intel BMC 에서 MCTP over PCIe VDM 통신 경로 분석

• Intel BMC GitHub : https://github.com/orgs/Intel-BMC/repositories?type=all
• libmctp
• astpcie.h 에서 선언된 참조 device file
• /* driver device file */
  #define AST_DRV_FILE "/dev/aspeed-mctp"
• https://github.com/Intel-BMC/libmctp/blob/master/astpcie.h
• astpcie.c 
• 위 file 을 open 하여 ioctl(), write, read 하여 통신.
  
• https://github.com/Intel-BMC/libmctp/blob/master/astpcie.c
• kernel 의 aspeed-mctp device driver
• drivers/soc/aspeed/aspeed-mctp.c
• AST2600 의 MCTP controller HW 에 access 하여 PCIe VDM MCTP 통신 수행
• https://github.com/Intel-BMC/linux/blob/dev-5.15-intel/drivers/soc/aspeed/aspeed-mctp.c
• AST2600 datasheet 에서 내용 확인 필요.

BMC chipset

출처: ASPEED - AST2600

AST2600

AST2600 is ASPEED's 7th generation Server Management Processor, and also the world's first BMC SoC adopting 28nm advanced process technology. Adopting the Dual-core ARM Cortex A7 processor, AST2600 can optimize the performance and computing power; also lower the power consumption significantly. Also, AST2600 support Secure Boot mode and ARM Cortex A7 TrustZone, which can provide customers excellent information security protection.

Embedded CPU	Dual-core ARM Cortex A7 Embedded ARM Cortex M3
SDRAM Memory	DDR4 SDRAM with speed grade higher than DDR4-1600Mbps Up to 2G Byte ECC option
Flash Memory	SPI flash memory SPI flash memory
Video-Over-IP	Video Redirection up to 1920x1200 YUV444/YUV420 Video Compression 24 bits video compression quality
USB-Over-IP	USB 2.0 virtual hub controller with 5 devices supported USB 1.1 HID device controller
BMC	BMC controller with IPMI 2.0/1.5 compliant Remote Presence (iKVM) PCIe host capability eSPI/LPC MCTP over PCIe I2C/I3C/SMBus (Total 16 sets) Virtual UART (1 set) UART (13 sets and 1 set for FW debug) GPIO (244 sets) SGPIO (80 bits) PWM (16 sets) Secure boot engine Fan tachometer (16 sets) PECI 4.0 USB1.1/2.0 Host SD/SDIO (2 ports) Embedded SRAM ADC (16 channels) Port 80h snoop Watchdog (3 sets) Timer (8 sets)
VGA	PCIe VGA/2D Controller 1920x1200@60Hz 32bpp
VGA Drivers	RHEL SLES Solaris Ubuntu FreeBSD Fedora Windows Server 2012 R2 (WHQL logo'ed) Windows Server 2016 (WHQL logo'ed) Windows Server 2019 (WHQL logo'ed)
LAN	Quad 10/100/1000M bps MAC
Technology	624-pin 21mmx21mm TFBGA package
Pin Compatibility	AST2620