Techniques of providing serial port in non-legacy system via embedded-system device

1. A method of operating an embedded-system device, comprising:

receiving first command or data through a first serial port of the embedded-system device;

exposing a second serial port to a host of the embedded-system device such that the host has control over the second serial port and receiving second command or data from the host for outputting at the second serial port;

redirecting the first command or data to the second serial port when the embedded-system device is in a first mode; and

allowing the second command or data to be output at the second serial port when the embedded-system device is in a second mode;

wherein the redirecting the first command or data includes, in the first mode:

constructing third command or data based on the first command or data; and

sending the third command or data to the second serial port for outputting.

2. The method of claim 1 , further comprising:

connecting with the host to become a super IO controller of the host, wherein the second serial port is exposed to the host as a serial port of the super IO controller.

3. The method of claim 1 , further comprising, in the first mode:

configuring a chip of the embedded-system device to open a communication channel between the first serial port with the second serial port, wherein the chip transfers, through the communication channel, the first command or data received at the first serial port to the second serial port without being processed by firmware of the embedded-system device.

4. The method of claim 1 , further comprising:

receiving a control command that includes an indication of the first mode or the second mode; and

setting the embedded-system device to operate in the first mode or the second mode according to the control command.

5. The method of claim 1 , further comprising:

receiving first signals at the first serial port;

operating a first serial port controller to process the first signals to generate the first command or data;

sending the third command or data to a second serial port controller;

generating, at the second serial port controller, second signals based on the third command or data; and

outputting the second signals at the second serial port.

6. The method of claim 4 , wherein the control command in an Intelligent Platform Management Interface (IPMI) command.

7. An apparatus, the apparatus being an embedded-system device, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

receive first command or data through a first serial port of the embedded-system device;

expose a second serial port to a host of the embedded-system device such that the host has control over the second serial port and receive second command or data from the host for outputting at the second serial port;

redirect the first command or data to the second serial port when the embedded-system device is in a first mode; and

allow the second command or data to be output at the second serial port when the embedded-system device is in a second mode;

wherein to redirect the first command or data, the at least one processor is further configured to, in the first mode:

construct third command or data based on the first command or data; and

send the third command or data to the second serial port for outputting.

8. The apparatus of claim 7 , wherein the at least one processor is further configured to:

connect with the host to become a super IO controller of the host, wherein the second serial port is exposed to the host as a serial port of the super IO controller.

9. The apparatus of claim 7 , wherein the at least one processor is further configured to:

receive first signals at the first serial port;

operate a first serial port controller to process the first signals to generate the first command or data;

send the third command or data to a second serial port controller;

generate, at the second serial port controller, second signals based on the third command or data; and

output the second signals at the second serial port.

10. The apparatus of claim 7 , wherein the at least one processor is further configured to, in the first mode:

configure a chip of the embedded-system device to open a communication channel between the first serial port with the second serial port, wherein the chip transfers, through the communication channel, the first command or data received at the first serial port to the second serial port without being processed by firmware of the embedded-system device.

11. The apparatus of claim 7 , wherein the at least one processor is further configured to:

receive a control command that includes an indication of the first mode or the second mode; and

set the embedded-system device to operate in the first mode or the second mode according to the control command.

12. The apparatus of claim 11 , wherein the control command in an Intelligent Platform Management Interface (IPMI) command.

13. A non-transitory computer-readable medium storing computer executable code for operating an embedded-system device, comprising code to:

receive first command or data through a first serial port of the embedded-system device;

expose a second serial port to a host of the embedded-system device such that the host has control over the second serial port and receive second command or data from the host for outputting at the second serial port;

redirect the first command or data to the second serial port when the embedded-system device is in a first mode; and

allow the second command or data to be output at the second serial port when the embedded-system device is in a second mode;

wherein to redirect the first command or data, the code is further configured to, in the first mode:

construct third command or data based on the first command or data; and

send the third command or data to the second serial port for outputting.

14. The non-transitory computer-readable medium of claim 13 , wherein the code is further configured to:

connect with the host to become a super IO controller of the host, wherein the second serial port is exposed to the host as a serial port of the super IO controller.

15. The non-transitory computer-readable medium of claim 13 , wherein the code is further configured to:

receive first signals at the first serial port;

operate a first serial port controller to process the first signals to generate the first command or data;

send the third command or data to a second serial port controller;

generate, at the second serial port controller, second signals based on the third command or data; and

output the second signals at the second serial port.

16. The non-transitory computer-readable medium of claim 13 , wherein the code is further configured to, in the first mode:

configure a chip of the embedded-system device to open a communication channel between the first serial port with the second serial port, wherein the chip transfers, through the communication channel, the first command or data received at the first serial port to the second serial port without being processed by firmware of the embedded-system device.

17. The non-transitory computer-readable medium of claim 13 , wherein the code is further configured to:

receive a control command that includes an indication of the first mode or the second mode; and

set the embedded-system device to operate in the first mode or the second mode according to the control command.