As a web front-end engineer, I'm going to write Linux insides notes, look at some operating system things, always think of those years looking at the Osdev wiki days, 30 days of no self-made operating system, and the halfway halfdogos ╯﹏╰ start the text. The computer is power-on, the CPU initializes the program pointer to the ROM in the Oxfffffffo position. into real mode, an ancient 8086-compatible mode, register only 16 bits, the bus only 20 bits, the result is the address space only 1m, in order to let the 16-bit register can only represent 64k register address 1MB space, first people invented the segmentation of this thing. Two registers, one represents the segment start address, one represents the offset, this is equivalent to the 32-bit register can seek 4g address, but the real mode address space only 1mb OK, Oxfffffffo contains to jump to the BIOS instruction, still in ROM, the BIOS has done the hardware self-test a great many things, Then find the bootable hardware. For example, the first 512-byte sector of a hard disk, this sector should be set according to the rules, such as the last Oxaa55 what. The BIOS will load the code such as this area into the RAM address Ox7coo jump, of course, in real mode, the other address what to do all the provisions, the bios of the initialization of what data should be put where, and then the program run to ox7coo,bootloader this thing, Can start from here tell, haha, at least I also rolling my own bootloader, but do not seem to understand the next chapter of the Linux insides to say what ⊙▽⊙ cheers!
Linux Insides Notes (i)
