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| 1 | +use crate::signature::FlashSize; |
| 2 | +use crate::stm32::FLASH; |
| 3 | +use core::{ptr, slice}; |
| 4 | + |
| 5 | +/// Flash erase/program error |
| 6 | +#[derive(Debug, Clone, Copy)] |
| 7 | +pub enum Error { |
| 8 | + ProgrammingSequence, |
| 9 | + ProgrammingParallelism, |
| 10 | + ProgrammingAlignment, |
| 11 | + WriteProtection, |
| 12 | + Operation, |
| 13 | +} |
| 14 | + |
| 15 | +impl Error { |
| 16 | + fn read(flash: &FLASH) -> Option<Self> { |
| 17 | + let sr = flash.sr.read(); |
| 18 | + if sr.pgserr().bit() { |
| 19 | + Some(Error::ProgrammingSequence) |
| 20 | + } else if sr.pgperr().bit() { |
| 21 | + Some(Error::ProgrammingParallelism) |
| 22 | + } else if sr.pgaerr().bit() { |
| 23 | + Some(Error::ProgrammingAlignment) |
| 24 | + } else if sr.wrperr().bit() { |
| 25 | + Some(Error::WriteProtection) |
| 26 | + } else if sr.operr().bit() { |
| 27 | + Some(Error::Operation) |
| 28 | + } else { |
| 29 | + None |
| 30 | + } |
| 31 | + } |
| 32 | +} |
| 33 | + |
| 34 | +/// Flash methods implemented for `stm32::FLASH` |
| 35 | +#[allow(clippy::len_without_is_empty)] |
| 36 | +pub trait FlashExt { |
| 37 | + /// Memory-mapped address |
| 38 | + fn address(&self) -> usize; |
| 39 | + /// Size in bytes |
| 40 | + fn len(&self) -> usize; |
| 41 | + /// Returns a read-only view of flash memory |
| 42 | + fn read(&self) -> &[u8] { |
| 43 | + let ptr = self.address() as *const _; |
| 44 | + unsafe { slice::from_raw_parts(ptr, self.len()) } |
| 45 | + } |
| 46 | + /// Unlock flash for erasing/programming until this method's |
| 47 | + /// result is dropped |
| 48 | + fn unlocked(&mut self) -> UnlockedFlash; |
| 49 | +} |
| 50 | + |
| 51 | +impl FlashExt for FLASH { |
| 52 | + fn address(&self) -> usize { |
| 53 | + 0x0800_0000 |
| 54 | + } |
| 55 | + |
| 56 | + fn len(&self) -> usize { |
| 57 | + FlashSize::get().bytes() |
| 58 | + } |
| 59 | + |
| 60 | + fn unlocked(&mut self) -> UnlockedFlash { |
| 61 | + unlock(self); |
| 62 | + UnlockedFlash { flash: self } |
| 63 | + } |
| 64 | +} |
| 65 | + |
| 66 | +const PSIZE_X8: u8 = 0b00; |
| 67 | + |
| 68 | +/// Result of `FlashExt::unlocked()` |
| 69 | +pub struct UnlockedFlash<'a> { |
| 70 | + flash: &'a mut FLASH, |
| 71 | +} |
| 72 | + |
| 73 | +/// Automatically lock flash erase/program when leaving scope |
| 74 | +impl Drop for UnlockedFlash<'_> { |
| 75 | + fn drop(&mut self) { |
| 76 | + lock(&self.flash); |
| 77 | + } |
| 78 | +} |
| 79 | + |
| 80 | +impl UnlockedFlash<'_> { |
| 81 | + /// Erase a flash sector |
| 82 | + /// |
| 83 | + /// Refer to the reference manual to see which sector corresponds |
| 84 | + /// to which memory address. |
| 85 | + pub fn erase(&mut self, sector: u8) -> Result<(), Error> { |
| 86 | + let snb = if sector < 12 { sector } else { sector + 4 }; |
| 87 | + |
| 88 | + #[rustfmt::skip] |
| 89 | + self.flash.cr.modify(|_, w| unsafe { |
| 90 | + w |
| 91 | + // start |
| 92 | + .strt().set_bit() |
| 93 | + .psize().bits(PSIZE_X8) |
| 94 | + // sector number |
| 95 | + .snb().bits(snb) |
| 96 | + // sectore erase |
| 97 | + .ser().set_bit() |
| 98 | + // no programming |
| 99 | + .pg().clear_bit() |
| 100 | + }); |
| 101 | + self.wait_ready(); |
| 102 | + self.ok() |
| 103 | + } |
| 104 | + |
| 105 | + /// Program bytes with offset into flash memory, |
| 106 | + /// aligned to 128-bit rows |
| 107 | + pub fn program<'a, I>(&mut self, mut offset: usize, mut bytes: I) -> Result<(), Error> |
| 108 | + where |
| 109 | + I: Iterator<Item = &'a u8>, |
| 110 | + { |
| 111 | + let ptr = self.flash.address() as *mut u8; |
| 112 | + let mut bytes_written = 1; |
| 113 | + while bytes_written > 0 { |
| 114 | + bytes_written = 0; |
| 115 | + let amount = 16 - (offset % 16); |
| 116 | + |
| 117 | + #[rustfmt::skip] |
| 118 | + self.flash.cr.modify(|_, w| unsafe { |
| 119 | + w |
| 120 | + .psize().bits(PSIZE_X8) |
| 121 | + // no sector erase |
| 122 | + .ser().clear_bit() |
| 123 | + // programming |
| 124 | + .pg().set_bit() |
| 125 | + }); |
| 126 | + for _ in 0..amount { |
| 127 | + match bytes.next() { |
| 128 | + Some(byte) => { |
| 129 | + unsafe { |
| 130 | + ptr::write_volatile(ptr.add(offset), *byte); |
| 131 | + } |
| 132 | + offset += 1; |
| 133 | + bytes_written += 1; |
| 134 | + } |
| 135 | + None => break, |
| 136 | + } |
| 137 | + } |
| 138 | + self.wait_ready(); |
| 139 | + self.ok()?; |
| 140 | + } |
| 141 | + self.flash.cr.modify(|_, w| w.pg().clear_bit()); |
| 142 | + |
| 143 | + Ok(()) |
| 144 | + } |
| 145 | + |
| 146 | + fn ok(&self) -> Result<(), Error> { |
| 147 | + Error::read(&self.flash).map(Err).unwrap_or(Ok(())) |
| 148 | + } |
| 149 | + |
| 150 | + fn wait_ready(&self) { |
| 151 | + while self.flash.sr.read().bsy().bit() {} |
| 152 | + } |
| 153 | +} |
| 154 | + |
| 155 | +const UNLOCK_KEY1: u32 = 0x45670123; |
| 156 | +const UNLOCK_KEY2: u32 = 0xCDEF89AB; |
| 157 | + |
| 158 | +fn unlock(flash: &FLASH) { |
| 159 | + flash.keyr.write(|w| unsafe { w.key().bits(UNLOCK_KEY1) }); |
| 160 | + flash.keyr.write(|w| unsafe { w.key().bits(UNLOCK_KEY2) }); |
| 161 | + assert!(!flash.cr.read().lock().bit()) |
| 162 | +} |
| 163 | + |
| 164 | +fn lock(flash: &FLASH) { |
| 165 | + flash.cr.modify(|_, w| w.lock().set_bit()); |
| 166 | +} |
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