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Update linux-bootstrap-1.md

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ckrooss 2015-01-04 18:33:44 +01:00
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@ -132,7 +132,7 @@ We will see:
In this example we can see that this code will be executed in 16 bit real mode and will start at 0x7c00 in memory. After the start it calls [0x10](http://www.ctyme.com/intr/rb-0106.htm) interrupt which just prints `!` symbol. It fills rest of 510 bytes with zeros and finish with two magic bytes 0xaa and 0x55. In this example we can see that this code will be executed in 16 bit real mode and will start at 0x7c00 in memory. After the start it calls [0x10](http://www.ctyme.com/intr/rb-0106.htm) interrupt which just prints `!` symbol. It fills rest of 510 bytes with zeros and finish with two magic bytes 0xaa and 0x55.
Real world boot loader starts at the same point, ends with `0x55aa` bytes, but reads kernel code from device, loads it to memory, parses and passes boot parameters to kernel and etc... intead of printing one symbol :) Ok, so, from this moment bios handed control to the operating system bootloader and we can go ahead. Real world boot loader starts at the same point, ends with `0xaa55` bytes, but reads kernel code from device, loads it to memory, parses and passes boot parameters to kernel and etc... intead of printing one symbol :) Ok, so, from this moment bios handed control to the operating system bootloader and we can go ahead.
**NOTE**: as you can read above CPU is in real mode. In real mode for calculating physical address in memory uses following form: **NOTE**: as you can read above CPU is in real mode. In real mode for calculating physical address in memory uses following form: