IPR-NIOS Altera, IPR-NIOS Datasheet - Page 180

• Manufacturer Part Number: IPR-NIOS
• Description: IP NIOS II MEGACORE RENEW
• Manufacturer: Altera
• Type: MegaCorer

Specifications of IPR-NIOS

• License: Renewal License
• Lead Free Status / RoHS Status: Not applicable / Not applicable

7–16
Nios II Processor Reference Handbook
Linux Process Initialization
Table 7–7. Signals for Unhandled Intruction-Related Exceptions
There are no floating-point exceptions. The optional floating point unit (FPU) does not
support exceptions and any process wanting exact IEEE conformance needs to use a
soft-float library (possibly accelerated by use of the attached FPU).
The break instruction in a user process might generate a SIGTRAP signal for that
process, but is not required to. Userspace programs should not use the break
instruction and userspace debuggers should not insert one. If no hardware debugger
is connected, the OS should assure that the break instruction does not cause the
system to stop responding. For information about userspace debugging, refer to
“Userspace Breakpoints” on page
The page size is 4 KB. Virtual addresses in user mode are all below 2 GB due to the
MMU design. The NULL page is not mapped.
The stack pointer, sp, points to the argument count on the stack.
initial state of the stack when a userspace process starts.
Table 7–8. Stack Initial State at User Process Start
If the application should register a destructor function with atexit, the pointer is
placed in r4. Otherwise r4 is zero.
The contents of all other registers are unspecified. User code should set fp to zero to
mark the end of the frame chain.
The auxiliary vector is a series of pairs of 32-bit tag and 32-bit value, terminated by an
AT_NULL tag.
TLB Permission Violation (read)
TLB Permission Violation (write)
Unspecified
Referenced strings
Unspecified
Null auxilliary vector entry
Auxilliary vector entries
NULL terminator for envp
Environment pointers
NULL terminator for argv
Argument pointers
Argument count
Unspecified
Purpose
Exception
High addresses
sp + 8 + 4 × argc
sp + 4 + 4 × argc
sp + 4
sp
Low addresses
7–21.
Start Address
SIGSEGV
SIGSEGV
Signal
Chapter 7: Application Binary Interface
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4 bytes each
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Varies
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December 2010 Altera Corporation
Length
Table 7–8
ABI for Linux Systems
shows the