You don't handle the CPU from the reset vector like you would in a microcontroller or system firmware environment. There is an entire loader stack that finds a boot device to read a kernel image from that exists under you.
That's not to take away from this series at all, it's just the parent comment was asking about how it was so easy to get into a kernel image written in C on an SD card without any apparent SD card or FS logic.
https://github.com/isometimes/rpi4-osdev/tree/master/part2-b...
https://raspberrypi.stackexchange.com/questions/10489/how-do...
You don't handle the CPU from the reset vector like you would in a microcontroller or system firmware environment. There is an entire loader stack that finds a boot device to read a kernel image from that exists under you.
That's not to take away from this series at all, it's just the parent comment was asking about how it was so easy to get into a kernel image written in C on an SD card without any apparent SD card or FS logic.