stm32flash

STM32 VFS

Simple VFS for SMT32 MCU and FS for spi flash devices. FS using only static allocation and requires minimum 8kB of RAM for it's operation. Because of only 1-level indirection maximum allowed file size is limited with approximately 16Mb. Every block has a CRC protection.

Structure

• main.c — a simple terminal program to demonstrate and test vfs functions.
• uartterm.c and uartterm.h — API and functions that implement unix-like ternimal working through UART.
• driver.h — common interface for drivers in this project.
• filesystem.c and filesystem.h — common interface for filesystems in this project.
• w25.c and w25.h — driver that implement most basic function of W25Q SPI flash memory.
• sfs.c and sfs.h — A simple filesystem.
• rfs.c and rfs.h — Filesystem that resides in RAM.
• call.c and call.h — Implementation for system call not related to VFS.

UART terminal

UART terminal is used for testing and resembeles typical UNIX shell.

Driver commands

• sd [dev] -- set current device to [dev]
• rd [addr] -- read data at address [addr]
• wd [addr] [str] -- write string [str] into [addr]

Filesystem commands

• f -- format choosen device
• i [struct] {[addr]} -- dump filesystem [struct] (sb, in, bm) at [addr]
• c [sz] -- create inode for data size of [size]
• d [addr] -- delete inode with address [addr]
• s [addr] [data] -- set data for inode with address [addr] to [data]
• g [addr] -- get data from inode with address [addr]
• r [addr] [off] [sz] -- read [sz] bytes from inode with address [addr] with offset of [off] bytes
• w [addr] [off] [data] -- write data into inode with address [addr] with offset of [off] bytes

Virtual filesystem commands

• mount [dev] [target] -- mount [dev] to [target]
• format [target] -- format device mounted at [target]
• umount [dev] [target] -- unmount [target]
• mountlist -- get list of mounted devices
• open [path] [flags] -- open file with [path], if [flags] is 'c', create it
• read [fd] [sz] -- read [sz] bytes from opened file with descriptor [fd]
• write [fd] [data] -- write [data] into opened file with descriptor [fd]
• close [fd] -- close opened file with descriptor [fd]
• mkdir [path] -- create directory [path]
• rm [path] -- delete file or directory [path]
• ls [path] -- get list of file in directory [path]
• cd [path] -- change current working directory to [path]

What's done

• Filesystem mounting/unmounting.
• open/close and read/write calls in VFS.
• Simple filesystem, bad version of ext with built-in checksums.
• Naive implementations of malloc/free/realloc.
• RAM filesystem and that malloc/free/realloc calls.
• Common interfaces for filesystems and drivers.

What's not done

• Device files
• Page cache
• Unit tests