Difference between revisions of "Console and outputs"

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(Ram buffer, like dmesg)
(Ram buffer, like dmesg)
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* output only
* output only for coreboot.
* input/output for grub.
It requires the computer to be booted to retrive the logs.
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For writting to the buffer which is in the coreboot target computer:
For writting to the buffer which is in the coreboot target computer:

Revision as of 12:45, 15 December 2013

Coreboot has various possible consoles:

Output name direction (from the target coreboot machine point of view) software compatibility (compatibility with software loaded after coreboot, like OS payloads etc...)
Serial console

(sends coreboot logs over the serial port)

  • input
  • output
  • seabios
  • grub as a payload
  • grub running after seabios
  • libpayload
  • linux kernel (loaded after the payload)
  • most GNU/Linux init systems(sysvinit, systemd, upstart etc...)
Console Over EHCI debug port

(sends coreboot logs over the usb debug port)

  • input?
  • output
Console trough spkmodem

(sends coreboot logs over the sound card)

  • output only

For writting to it from the coreboot target computer:

  • coreboot's console
  • grub's console

For reading it from a remote computer:

  • coreboot's/grub's spkmodem_recv uttilty (same uttility, but it's available in both git repositories)
Network console

(sends coreboot logs over the network)

  • output
Cbmem console

(Ram buffer, like dmesg)

  • output only for coreboot.
  • input/output for grub.

It requires the computer to be booted to retrive the logs.

For writting to the buffer which is in the coreboot target computer:

  • coreboot console output
  • grub console output
  • seabios

For reading the buffer on the coreboot target computer, after coreboot booted:

  • grub with the cbmemc command
  • coreboot's userspace cbmem -c uttility

Other output: