Create Snapshot Image With memmap Tools
Build memmap Tools
If you are using "Load Pre-Saved Snapshot Image Mode", use the memmap tool to generate the required pre-saved snapshot image.
Download the memmap tool from GitHub®. See the GitHub source memmap tools page.
Install memmap tools on Linux®.
Unzip memmap-main.zip.
Run the following command to build mem_map tools:
Run the following command to test the mem_map tools:
Edit JSON File With memmap Parameters
Edit and update the parameters in snapshot.json. Run the following command to load the parameters in the snapshot.json file:
This is an example:
cat snapshot.json
{
"ddr-base": 0x60000000,
"block-size": 0x200,
"block-align": 64,
"auto-mode": false,
"zero-page": false,
"secure": false,
"dump": false,
"crc": false,
"mem-map": {
"canary": 0x60e08360,
"resume": 0x6010ab98,
"mem-map": 0x8f7fa000,
"max-mapnr": 0x40000,
"struct-size": 0x20,
"page-shift": 0xc,
"page-type": 0xf0,
"page-off": 0x18,
"order-off": 0x14,
"linux-ver": 0x5
},
"secure-info": {
"key-size": 192,
"key-0": 0x0,
"key-1": 0x1,
"key-2": 0x2,
"key-3": 0x3,
"key-4": 0x4,
"key-5": 0x5,
"key-6": 0x6,
"key-7": 0x7,
"iv-0": 0x1,
"iv-1": 0x2,
"iv-2": 0x3,
"iv-3": 0x4
}
}
cat snapshot.json
{
"ddr-base": 0x60000000,
"block-size": 0x200,
"block-align": 64,
"auto-mode": false,
"zero-page": false,
"secure": false,
"dump": false,
"crc": false,
"mem-map": {
"canary": 0x60e08360,
"resume": 0x6010ab98,
"mem-map": 0x8f7fa000,
"max-mapnr": 0x40000,
"struct-size": 0x20,
"page-shift": 0xc,
"page-type": 0xf0,
"page-off": 0x18,
"order-off": 0x14,
"linux-ver": 0x5
},
"secure-info": {
"key-size": 192,
"key-0": 0x0,
"key-1": 0x1,
"key-2": 0x2,
"key-3": 0x3,
"key-4": 0x4,
"key-5": 0x5,
"key-6": 0x6,
"key-7": 0x7,
"iv-0": 0x1,
"iv-1": 0x2,
"iv-2": 0x3,
"iv-3": 0x4
}
}
- ddr-base: DRAM base address
- 0x20000000 for SAM9X60, SAM9X7 and SAMA5D2
- 0x60000000 for SAMA7G54 and SAMA7D65
- block size: the smallest physical storage unit on flash memory
- 0x200 for SD, eMMC card and Quad Serial Peripheral Interface (QSPI) flash
- 0x1000 for NAND flash
- block-align: block size in page
- 0 for SD™, eMMC card and QSPI flash
- 64 for NAND flash（for NAND flash, the block size is 0x40000）
- zero-page:
- true: enable Zero-Page optimization mode
- false: disable Zero-Page optimization mode
- Secure:
- true: enable secure snapshot mode
- false: disable secure snapshot mode
- dump
- true: outputs the fast boot configuration to the debug console
- false: does not output any messages
- crc
- true: generate CRC-32 code for snapshot image validation.
- false: do not generate CRC-32
- memmap: memory mapping parameters
You can find most of these parameters in the kernel boot console message (requires the Ultra-Fast Boot patch) and use this data to fill the mem-map structure.
For example:
- Canary: canary data for memory checking after exit from backup mode
- Resume: CPU resume address
- mem-map: The start virtual address of kernel 'page' structures
- max-mapnr: The maximum Number of Mapped Pages
- struct-size: The size of ‘struct page’ structure
- page-shift: The offset of ‘page-shift’ in ‘struct page’
- page-type: The offset of ‘page_type’ in ‘struct page’
- page-off: The offset of ‘page_type’ in ‘struct page’
- order-off: The offset of ‘private' in ‘struct page’
- linux-ver: Linux kernel version
- 0 Yes Linux 6.12.48 linux4microchip-2025.10
- 1 Yes Linux 6.12.22 linux4microchip-2025.04
- 2 TBD Linux 6.11.11
- 3 TBD Linux 6.10.14
- 4 TBD Linux 6.6.51 linux4microchip-2024.10
- 5 TBD Linux 6.6.23 linux4microchip-2024.04
- secure-info: secure parameters
- key-size: select the length of the cipher -> 128 | 192 | 256
- key-x: cipher words
- iv-x: initialization vector words
Trim and save the Linux runtime snapshot image with:
Example: Convert ddr-2g-raw.bin and save it as snapshot.bin
