ESP8266 Flash
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目录?[隐藏]?
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1 概述
4KB 为一个扇区 (Sector),The last 16 sectors is the paramter area!
1MB flash is start at 0xF0000
4MB flash is start at 0x3F0000
1.1 系统参数区 (System param)
始终为 Flash 的最后 16KB
- 4KB 为初始化射频参数 (esp_init_data_default.bin); The last sector 12; 4MB Flash 为:0x3FC000 - 0x3FCFFF
- 8KB 为初始化系统参数 (blank.bin); The last sector 13 and 14,4KB + 4KB mirror; 4MB Flash 为:0x3FD000 - 0x3FEFFF
- 4KB is bootloader parameters area; The last sector 15; 4MB flash is at: 0x3FF000
皆由 SDK 提供
For MJYUN:
- 8KB is MJYUN parameter area; The last sector 4 and 5,4KB + 4KB mirror; 4MB flash is: 0x3F4000 - 0x3F5FFF
1.2 用户参数区 (User param)
指 Espressif 提供的示例 (IOT_Demo / AT) 中设定的用户参数区
iBaihe 的参数: 0x3C * 4KB = 0x3C000
COS Platform 参数:
(0x3C + 1) * 4KB = 0x3D000 (SAVE_0) (0x3C + 2) * 4KB = 0x3E000 (SAVE_1) (0x3C + 3) * 4KB = 0x3F000 (PARAM_FLAG)
2 Layout Without OTA
Address Size Name Description 00000h 4k boot.bin Bootloader 3C000h 14k Param Start Sector 3D000h 1x4k Param Saved 0 3E000h 1x4k Param Saved 1 3F000h 1x4k Param Flag 40000h 240k app.v6.irom0text.bin SDK libraries 7C000h 8k esp_init_data_default.bin Default configuration 7E000h 8k blank.bin Filled with FFh. May be WiFi configuration
3 Layout With OTA
3.1 512 和 1024KB
3.2 4096KB
4 SPI Flash Format
- http://esp8266-re.foogod.com/wiki/SPI_Flash_Format
5 SPI Flash Mode
- QIO,for flash that support quad r/w operation(e.g. W25Q)
- QOUT,for flash that support quad read operation(e.g. W25Q)
- DIO,for flash that support dual r/w operation(e.g. W25Q &W25X)
- DOUT,for flash that support dual read operation(e.g. W25Q &W25X)
经测试:
- Winbond 25Q32B 可工作于 DIO / DOUT / QIO /QOUT (Noduino Falcon)
- BergMicro 25Q32A 只可工作于 DIO / DOUT (NodeMCU V1.0 可能是 ESP-12E 接线的问题)
- MXIC 25L80 (小 K mini)只可工作于 DOUT
6 Flash Memory Map
- Map the flash
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2
3
4
5
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/*
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* Memory map first 8Mbit of flash
* address space is: 0x4020 0000 - 0x402F FFFF
*/
Cache_Read_Enable (0,0);
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- Unmap the flash
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Cache_Read_Disable();
6.1 Cache_Read_Enable
void Cache_Read_Enable(uint8 odd_even,uint8 mb_count,unt8 no_idea);
Valid values for odd_even:
0 – clears bits 24 & 25 of control register 0x3FF0000C 1 – clears bit 24,sets bit 25
other – clears bit 25,sets bit 24
Function of odd_even:
0 – allows access to even numbered mb 1 – allow access to odd numbered mb
other – appears to do the same as 1,there must be a difference but I haven’t worked out what it it
Valid values for mb_count:
0-7 – set bits 16,17 & 18 of control register 0x3FF0000C
Function of mb_count:
Which odd or even bank to map (according to odd_even option)
e.g. mb_count = 0,odd_even = 0 -> map first 8Mbit of flash e.g. mb_count = 0,odd_even = 1 -> map second 8Mbit of flash e.g. mb_count = 1,odd_even = 0 -> map third 8Mbit of flash e.g. mb_count = 1,odd_even = 1 -> map fourth 8Mbit of flash
Valid values for no_idea:
0 – sets bit 3 of 0x3FF00024 1 – sets bit 26 of 0x3FF0000C and sets bits 3 & 4 of 0x3FF00024
Function of no_idea:
The clue is in the name,I can’t work out what this does from my experiments,but the SDK always sets this to 1.
- Reverse engineered by Richard Burton:?http://richard.burtons.org/2015/06/12/esp8266-cache_read_enable/
7 Reference
- https://www.winbond.com/hq/product/code-storage-flash-memory/serial-nor-flash/?__locale=en&density=8Mbit(1MB)#density