Epson S5U1C17001C Manual page 272

5 gnU17 iDE
Shown below are section locations and file configurations.
main.o – .data
boot.o – .data
(__START_data_lma)
library – .rodata
main.o – .rodata
(__START_rodata)
library – .text
main.o – .text
boot.o – .text
(__START_text)
boot.o – .rodata
0x008000
0x000000
The .bssS1 and .bssS2 sections are located in parallel. The application determines which section is man-
aged and what data is used.
Example 4: Executing a program in raM
A routine that requires high-speed processing can be executed in RAM that can be accessed without wait states
to meet specific requirements. In the examples seen so far, only the VMA of the .text section is specified,
and the program is executed in ROM. However, the program can be executed in RAM by first specifying the
VMA and LMA, as for the .data section, then copying the program to RAM before execution. Additionally,
multiple sections may be allocated to the same area, as in Example 3, and the program may be executed by ex-
changing sections as necessary.
0x008000
0x000fbf
0x000000
Example of a source file configuration
(vector table and stack initialization, etc.)
boot.s
(main and other functions)
main.c
func1.c (program 1 to be executed in RAM)
func2.c (program 2 to be executed in RAM)
5-150
LMA
.data
section
.rodata
section
.text
section
.vector
section
No sections/files
located here
Figure 5.7.6.7 Example of a section location 3
ROM
Unused area
Program storage area
Program storage area
Variables
with initial values
Constants
and other static data
Program storage/
execution area
Vector table
RAM
Stack area
Program cache
Variables
with initial values
Variables
without initial values
Figure 5.7.6.8 Allocating a storage area for the program in RAM
(__START_bssS1)
(__START_data)
0x000000
.textu2 section (LMA)
.textu1 section (LMA)
.data section (LMA)
.rodata section (LMA=VMA)
.text section (LMA=VMA)
.vector section (LMA=VMA)
.textu1 and .textu2 sections (VMA)
located in the same area
.data section (VMA)
.bss section (VMA)
EPSOn
(C COMPilEr PaCkagE fOr S1C17 faMily) (Ver. 1.5.0)
VMA
.bssS1 section .bssS2 section
bss1.o – .bss bss2.o – .bss
main.o – .data
.data
section
boot.o – .data
library – .bss
main.o – .bss
.bss
section
boot.o – .bss
Program
copied
S5U1C17001C ManUal