Feature Request: server default system prompt support like -spf in old version support gemma2

[atozj]

Prerequisites

• I am running the latest code. Mention the version if possible as well.
• I carefully followed the README.md.
• I searched using keywords relevant to my issue to make sure that I am creating a new issue that is not already open (or closed).
• I reviewed the Discussions, and have a new and useful enhancement to share.

Feature Description

It seems that -p --prompt is not working.
need -spf system prompt file in llama-server，but it has removed。

#9811
We can probably think about reintroducing the option and use the CLI system prompt as default value for the chat template system prompt when it is not passed by the client.

Motivation

default system prompt make model behave better

Possible Implementation

like -spf in old version

[atozj]

give an example of several scenarios I want to implement. Let's assume the startup prompt is 'a', the user system prompt is 'b', and the user prompt is 'c'.
1.When the user does not input a system prompt: The total input will be 'a' + 'c'.
2.When the user inputs a system prompt: The total input will be 'b' + 'c' or 'a' + 'b' + 'c'.
The purpose of this approach is to enhance my friends' experience with open-source AI and make it more enjoyable. Teaching them how to set up prompts and other configurations is often too cumbersome, and they tend to give up quickly. Using a startup prompt effectively simplifies the process and improves the overall user experience.
This translation maintains the technical details while using natural English phrasing. It also preserves the explanatory tone of the original text. Let me know if you need any adjustments!

[ggerganov]

I'm not sure what you mean by "startup prompt". Models today only have "system prompt" which is optionally the first message in the chat. Thanks to the prompt caching functionality, the system prompt is always reused automatically.

[atozj]

maybe like this
[startup prompt]
<|im_start|>system
[user system prompt]<|im_end|>
<|im_start|>user
Hello<|im_end|>
<|im_start|>assistant

or

<|im_start|>system
[startup prompt]+[user system prompt]<|im_end|>
<|im_start|>user
Hello<|im_end|>
<|im_start|>assistant