User Guide
Table Of Contents
- Generic Nios II Booting Methods User Guide
- Overview
- Prerequisites
- Acronym
- Nios II Processor Boot Copier
- Nios II Processor Booting Methods
- Nios II Booting General Flow
- Summary of Nios II Processor Vector Configurations and BSP Settings
- Nios II Processor Application Execute-In-Place from CFI Flash
- Nios II Processor Application Copied from CFI Flash to RAM Using Boot Copier
- Nios II Processor Application Copied from EPCS Flash to RAM Using Boot Copier
- Nios II Booting Elements
- Nios II Programming Solutions
- Document Revision History for Generic Nios II Booting Methods
You may enable the alt_load() function in the HAL code. is function operates as a mini boot copier
that copies only the writable memory sections to RAM based on the BSP settings. It optionally copies
sections from the boot memory to RAM. It can copy data sections (.rodata, .rwdata, .exceptions) to RAM
but not the code sections (.text). e code section (.text) section is a read-only section and remains in the
booting ash memory region. is partitioning helps to minimize the RAM usage but may limit the code
execution performance because accesses to ash memory are slower than accesses to the on-chip RAM.
e alt_load() function can be enabled in the BSP Settings.
BSP Settings Functions
(1)
hal.linker.enable_alt_load Enable alt_load() function.
hal.linker.enable_alt_load_copy_
rodata
alt_load() copies .rodata section to RAM.
hal.linker.enable_alt_load_copy_
rwdata
alt_load() copies .rwdata section to RAM.
hal.linker.enable_alt_load_copy_
exceptions
alt_load() copies .exceptions section to RAM.
For more information about the Nios II default sections and the alt_load() function, please refer to the
"Nios II Soware Build Tools" chapter in the Nios II Classic Soware Developer’s Handbook.
Besides the alt_load() function, there are two types of Nios II boot copiers to support Nios II system
booting:
• Memcpy-based boot copier
• EPCS Controller- based boot copier
Related Information
Nios II Classic Soware Developer's Handbook
Memcpy-Based Boot Copier
Memcpy-based boot copier supports MAX
®
10 UFM, EPCQ and CFI ash memory. e boot copier is
stored within the ash memory as the ash controller supported Execute-in-Place (XiP). Subsequent boot
image is located just right aer the boot copier. You need to ensure the Nios II reset vector oset points to
the start of the boot copier.
e following gure shows the ash memory map for EPCQ and CFI ash when using a boot copier. is
memory map assumes a FPGA image is stored at the start.
(1)
.text, .rodata, .rwdata and .exceptions are part of the Nios II default section names.
UG-20001
2016.05.24
Memcpy-Based Boot Copier
3
Generic Nios II Booting Methods User Guide
Altera Corporation
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