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Remove POMS memory model comment

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The POMS memory model is not supported.

Change-Id: I9af7798be2e234c8a4adfde200187ffceacf89df
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
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Peter Mitsis 2015-04-27 11:51:26 -04:00 • committed by Anas Nashif
commit f6e34618a8
1 changed files with 0 additions and 13 deletions
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arch/x86/bsp/crt0.s
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@ -52,19 +52,6 @@ via GRUB or any other multiboot compliant bootloader) now assume that the
system is already in 32-bit protected mode and address line A20 is enabled. system is already in 32-bit protected mode and address line A20 is enabled.
However, the code associated with CONFIG_PROT_MODE_SWITCH has been left However, the code associated with CONFIG_PROT_MODE_SWITCH has been left
in place in case future booting scenarios arise which require its use. in place in case future booting scenarios arise which require its use.
POMS memory model
When a kernel configured for POMS starts, it runs at a physical address that
is different from the logical address it has been linked at. So, symbols are not
accessible without doing some translation. It is best then to run at a logical
address ASAP to access give access to symbols, especially to be able to run C
code. To do that, we start using segment selectors for CS/DS/SS that are mapping
the physical location to the logical location at which the kernel is linked, ie.
0x1000. Those segment selectors are 0x18 for CS and 0x20 for DS/SS.
Before these are used, the startup code uses physical address locations of
some key symbols (eg. the gdt) provided by the linker script.
*/ */
#define _ASMLANGUAGE #define _ASMLANGUAGE