ARM Compiler toolchain Using the Linker - ARM Information Center

Using scatter files
Example 8-5 Using the FIXED attribute
LR_1 0x040000 ; load region starts at 0x40000
{ ; start of execution region descriptions
ER_RO 0x040000 ; load address = execution address
{
* (+RO) ; RO sections other than those in init.o
}
ER_INIT 0x080000 FIXED ; load address and execution address of this
; execution region are fixed at 0x80000
{
init.o(+RO) ; all RO sections from init.o
}
... ; rest of scatter-loading description
}
8.9.1 Examples of misusing the FIXED attribute
The following example shows common cases where the FIXED execution region attribute is
misused:
Example 8-6 Misuse of the FIXED attribute
LR1 0x8000
{
ER_LOW +0 0x1000
{
*(+RO)
}
; At this point the next available Load and Execution address is 0x8000 + size of
; contents of ER_LOW. The maximum size is limited to 0x1000 so the next available Load
; and Execution address is at most 0x9000
ER_HIGH 0xF0000000 FIXED
{
*(+RW+ZI)
}
; The required execution address and load address is 0xF0000000. The linker inserts
; 0xF0000000 - (0x8000 + size of(ER_LOW)) bytes of padding so that load address matches
; execution address
}
; The other common misuse of FIXED is to give a lower execution address than the next
; available load address.
LR_HIGH 0x100000000
{
ER_LOW 0x1000 FIXED
{
*(+RO)
}
; The next available load address in LR_HIGH is 0x10000000. The required Execution
; address is 0x1000. Because the next available load address in LR_HIGH must increase
; monotonically the linker cannot give ER_LOW a Load Address lower than 0x10000000
}
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