I'm currently reading about the Napoleon's campaign in Egypt and Syria, and in the process, I learned of Roustam Raza, a fifteen-year old Mamluk boy who was presented to Napoleon as a gift while in Cairo. Raza later returned to France with Napoleon after the campaign and became his loyal bodyguard for many years to come.

I'm curious to learn the exact date he was presented to Napoleon. Some (not super scholarly) "sources" simply say 1798, like on Wikipedia, others says August of 1799, like here.

Was he there (serving Napoleon) for most of the campaign, as early as the Revolt of Cairo or the Siege of Jaffa, or did he merely tag along much later, right before Napoleon returned to France?

It's not mentioned at all, it seems, in Juan Cole's book on the matter.