Vault 7: Projects

This publication series is about specific projects related to the Vault 7 main publication.

MPLAB
®
XC16 C Compiler Users Guide
DS50002071C-page 42 2012-2013 Microchip Technology Inc.
2.5.13.2 DIFFERENCES
The 8-bit compilers have used the #pragma psect directive to redirect objects to a
new section, or psect. The operation of the __section() specifier is different to this
pragma in several ways, described below.
Unlike with the pragma, the new psect created with __section() does not inherit the
flags of the psect in which the object would normally have been allocated. This means
that the new psect can be linked in any memory area, including any data bank. The
compiler will also make no assumptions about the location of the object in the new sec-
tion. Objects redirected to new psects using the pragma must always be linked in the
same memory area, albeit at any address in that area.
The __section() specifier allows objects that are initialized to be placed in a different
psect. Initialization of the object will still be performed even in the new psect. This will
require the automatic allocation of an additional psect (whose name will be the same
as the new psect prefixed with the letter i), which will contain the initial values. The
pragma cannot be used with objects that are initialized.
Objects allocated a different psect with __section() will be cleared by the runtime
startup code, unlike objects which use the pragma.
You must reserve memory, and locate via a linker option, for any new psect created with
a __section() specifier in the current XC8 compiler implementation.
The 16- and 32-bit compilers have used the section attribute to indicate a different
destination section name. The __section() specifier works in a similar way to the
attribute.
2.5.13.3 MIGRATION TO THE CCI
For XC8, change any occurrence of the #pragma psect directive, such as
#pragma psect text%%u=myText
int getMode(int target) {
//...
}
to the __section() specifier, as in
int __section ("myText") getMode(int target) {
//...
}
For 16- and 32-bit compilers, change any occurrence of the section attribute, as in
the following example:
int __attribute__((section("myVars"))) intMask;
to:
int __section("myVars") intMask;
2.5.13.4 CAVEATS
With XC8, the __section() specifier cannot be used with any interrupt function.

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