[question]A request on c-based bbl payload example

[SoloGao]

Hi, I'm new for risc-v development. We aim to build a risc-v machine mode program can run on spike. Because we want to use htif functions, we try to use bbl with --enable-boot-machine, just like what's mentioned in #104 .
However, because the dummy payload is written purely in ASM, and used some "magic for me" ecalls, I can neither reproduce the "sbi_console_putchar" and "sbi_shutdown" in c, nor make a usable ld to link all things together. Could someone give a payload example in c to show how to build/how to use the putchar/shutdown function? Thanks!