protected_mode()
QNX SDP8.0Building Embedded SystemsConfigurationDeveloper
Switches the x86 processor to protected mode (non-BIOS systems)
Description:
This assembly function switches the x86 processor to protected mode. It is for non-BIOS systems only. The code is designed to be completely position-independent.
This function must be called with a pointer to a 16-byte area of memory that's used to store the Global
Descriptor Table (GDT). This pointer is in ds:ax
.
When this call returns, the DS and ES registers will have been set to selectors that can access the entire 4 GB address space. The following selectors are defined:
- 8
- Data selector for 0-4 GB.
- 16
- Code selector for 0-4 GB.
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