TASKING VX-toolset for ARM User Guide

TASKING VX-toolset for ARM User GuideIn the right pane the Settings appear.3. On the Tool Settings tab, select Linker » Optimization.4. Enable one or more optimizations.You can enable or disable the optimizations described below. The command line option for eachoptimization is given in brackets.Delete unreferenced sections (option -Oc/-OC)This optimization removes unused sections from the resulting object file.First fit decreasing (option -Ol/-OL)When the physical memory is fragmented or when address spaces are nested it may be possible that agiven application cannot be located although the size of the available physical memory is larger than thesum of the section sizes. Enable the first-fit-decreasing optimization when this occurs and re-link yourapplication.The linker's default behavior is to place sections in the order that is specified in the LSL file (that is, workingfrom low to high memory addresses or vice versa). This also applies to sections within an unrestrictedgroup. If a memory range is partially filled and a section must be located that is larger than the remainderof this range, then the section and all subsequent sections are placed in a next memory range. As a resultof this gaps occur at the end of a memory range.When the first-fit-decreasing optimization is enabled the linker will first place the largest sections in thesmallest memory ranges that can contain the section. Small sections are located last and can likely fit inthe remaining gaps.Compress copy table (option -Ot/-OT)The startup code initializes the application's data areas. The information about which memory addressesshould be zeroed and which memory ranges should be copied from ROM to RAM is stored in the copytable.When this optimization is enabled the linker will try to locate sections in such a way that the copy tableis as small as possible thereby reducing the application's ROM image.Delete duplicate code (option -Ox/-OX)Delete duplicate constant data (option -Oy/-OY)These two optimizations remove code and constant data that is defined more than once, from the resultingobject file.Compress ROM sections of copy table items (option -Oz/-OZ)Reduces the size of the application's ROM image by compressing the ROM image of initialized datasections. At application startup time the ROM image is decompressed and copied to RAM.206