ARM Compiler toolchain Using the Linker - ARM Information Center

Using scatter files
8.39 Type 2 image, one load region and non-contiguous execution regions
An image of this type consists of a single load region in the load view and three execution
regions in the execution view. It is similar to images of type 1 except that the RW execution
region is not contiguous with the RO execution region.
--ro_base=address1 specifies the load and execution address of the region containing the RO
output section. --rw_base=address2 specifies the execution address for the RW execution region.
The following example shows the scatter-loading description equivalent to using
--ro_base=0x010000 --rw_base=0x040000:
Example 8-24 Single load region and multiple execution regions
LR_1 0x010000 ; Defines the load region name as LR_1
{
ER_RO +0 ; The first execution region is called ER_RO and starts at end of previous region.
; Because there is no previous region, the address is 0x010000.
{
* (+RO) ; All RO sections are placed consecutively into this region.
}
ER_RW 0x040000 ; Second execution region is called ER_RW and starts at 0x040000.
{
* (+RW) ; All RW sections are placed consecutively into this region.
}
ER_ZI +0 ; The last execution region is called ER_ZI.
; The address is 0x040000 + size of ER_RW region.
{
* (+ZI) ; All ZI sections are placed consecutively here.
}
}
8.39.1 rwpi example variant
In this example:
• This description creates an image with one load region, named LR_1, with a load address
of 0x010000.
• The image has three execution regions, named ER_RO, ER_RW, and ER_ZI, that contain the
RO, RW, and ZI output sections respectively. The RO region is a root region. The
execution address of ER_RO is 0x010000.
• The ER_RW execution region is not contiguous with ER_RO. Its execution address is 0x040000.
• The ER_ZI execution region is placed immediately following the end of the preceding
execution region, ER_RW.
This is similar to images of type 2 with --rw_base where the RW execution region is separate
from the RO execution region. However, --rwpi marks the execution regions containing the RW
output section as position-independent.
The following example shows the scatter-loading description equivalent to using
--ro_base=0x010000 --rw_base=0x018000 --rwpi:
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