ARM Compiler toolchain Using the Linker - ARM Information Center

8.24 Placing a structure over a peripheral register using __at
8.24.1 See also
Using scatter files
To place an uninitialized variable over a peripheral register, a ZI __at section can be used.
Assuming a register is available for use at 0x10000000, define a ZI __at section called
.ARM.__at_0x10000000. For example:
int foo __attribute__((section(“.ARM.__at_0x10000000”), zero_init));
The following example shows the a scatter file with the manual placement of the ZI __at section:
ER_PERIPHERAL 0x10000000 UNINIT
{
*(.ARM.__at_0x10000000)
}
Example 8-15 Manual placement of ZI __at sections
Using automatic placement, assuming that there is no other execution region near 0x10000000,
the linker automatically creates a region with the UNINIT attribute at 0x10000000. The UNINIT
attribute creates an execution region containing uninitialized data or memory-mapped I/O.
Concepts
• Using __at sections to place sections at a specific address on page 8-37.
Linker Reference:
• About execution region descriptions on page 4-8.
Reference
Linker Reference:
• Execution region attributes on page 4-11.
Compiler Reference:
• __attribute__((section("name"))) variable attribute on page 5-72.
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