A method of generating updated object code (305, 1105, 1125) of a computer program, the updated object code being suitable as an input to a linker component (306, 1106) for the generation of an updated memory image to be loaded into a storage medium having stored thereon a current memory image corresponding to a current version of said computer program, wherein the steps of the method are performed by a compiler or a post-processor to a compiler, wherein the method comprises: - receiving (901, 303, 1103) at least one updated input code module (302, 1102, 803) from which the updated object code is to be generated; - processing at least the updated input code module to generate at least one updated object code module adapted to be linked by a linker component (306, 1106) as to generate the updated memory image; characterised in that the method further comprises - receiving processing information about a previous processing step that resulted in a set of current object code modules corresponding to the current version of said computer program, wherein the processing information includes at least one of current layout information indicative of a current layout of a set of object module parts within the current object code module and compiler information about a previous compilation step, and control data from a linker component indicative of size constraints to be imposed on the updated object code modules; and that processing at least the updated input code module (302, 1102, 803) comprises: - performing (903, 303, 1103, 1123) at least one optimisation process to reduce differences between said updated object code module and a corresponding one of the set of current object code modules, the set of current object code modules corresponding to the current version of said computer program, wherein the optimisation process is performed prior to feeding the updated object code module to a linker component; and wherein the optimisation step comprises, if the size of the updated object code module is larger than the size of the corresponding one of the set of current object code modules obtained from the processing information and optionally than the size constraints of the control data, to generate a split updated object code module split into a first updated object code module having a size no larger than the corresponding one of the set of current object code modules and an overflow object code module or overflow object code module part. - receiving (901, 303, 1103) at least one updated input code module (302, 1102, 803) from which the updated object code is to be generated; - processing at least the updated input code module to generate at least one updated object code module adapted to be linked by a linker component (306, 1106) as to generate the updated memory image; - receiving processing information about a previous processing step that resulted in a set of current object code modules corresponding to the current version of said computer program, wherein the processing information includes at least one of current layout information indicative of a current layout of a set of object module parts within the current object code module and compiler information about a previous compilation step, and control data from a linker component indicative of size constraints to be imposed on the updated object code modules; and that processing at least the updated input code module (302, 1102, 803) comprises: - performing (903, 303, 1103, 1123) at least one optimisation process to reduce differences between said updated object code module and a corresponding one of the set of current object code modules, the set of current object code modules corresponding to the current version of said computer program, wherein the optimisation process is performed prior to feeding the updated object code module to a linker component; and wherein the optimisation step comprises, if the size of the updated object code module is larger than the size of the corresponding one of the set of current object code modules obtained from the processing information and optionally than the size constraints of the control data, to generate a split updated object code module split into a first updated object code module having a size no larger than the corresponding one of the set of current object code modules and an overflow object code module or overflow object code module part.