Abi For Linux Systems - Altera Nios II User Manual

7–10
Table 7–4. Nios II Relocation Calculation (Part 3 of 3)
Name
R_NIOS2_COPY (3)
R_NIOS2_GLOB_DAT (3)
R_NIOS2_JUMP_SLOT (3)
R_NIOS2_RELATIVE (3)
R_NIOS2_GOTOFF (3)
Notes to Table 7–4:
(1) For relocation types where no overflow check is performed, the relocated address is truncated to fit the instruction.
(2) Expressions in this column use the following conventions:
S: Symbol address
■
A: Addend
■
PC: Program counter
■
■ GP: Global pointer
■ Adj(X): (((X >> 16) & 0xFFFF) + ((X >> 15) & 0x1)) & 0xFFFF
■ BA: The base address at which a shared library is loaded
■ GOT: The value of the Global Offset Table (GOT) pointer (Linux only)
■ G: The offset into the GOT for the GOT slot for symbol S (Linux only)
(3) Relocation support is provided for Linux systems.
With the information in
manipulating it as an unsigned 32-bit integer, as follows:
Xr = (( R << B ) & M | ( X & ~M ));
where:
R is the relocated address, calculated as listed in
■
■ B is the bit shift listed in
■ M is the bit mask listed in
■ X is the original instruction
■ Xr is the relocated instruction

ABI for Linux Systems

This section describes details specific to Linux systems beyond the Linux-specific
information in
Nios II Processor Reference Handbook
Overflow
Value
check (1)
Refer to
36 No
page 7–12
37 No S
Refer to
38 No
page 7–12
39 No BA+A
40 No S+A
Table 7–4, any Nios II instruction can be relocated by
Table 7–4
Table 7–4
Table 7–2 on page 7–2
Chapter 7: Application Binary Interface
Relocated Address
R (2)
"Copy Relocation" on
"Jump Slot Relocation" on
Table 7–4
and Table 7–4 on page
ABI for Linux Systems
Bit Mask Bit Shift
M B
n/a n/a
0xFFFFFFFF 0
0xFFFFFFFF 0
0xFFFFFFFF 0
0xFFFFFFFF 0
7–8.
February 2014 Altera Corporation