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rp: Read flash unique id and jedec id

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This commit is contained in:
kalkyl 2023-05-16 11:21:17 +02:00
parent b0541c01be
commit ab63f3832f
2 changed files with 241 additions and 0 deletions
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231
embassy-rp/src/flash.rs
View file

@ -187,6 +187,23 @@ impl<'d, T: Instance, const FLASH_SIZE: usize> Flash<'d, T, FLASH_SIZE> {
crate::multicore::resume_core1();
Ok(())
}
/// Read SPI flash unique ID
pub fn unique_id(&mut self, uid: &mut [u8]) -> Result<(), Error> {
unsafe { self.in_ram(|| ram_helpers::flash_unique_id(uid, true))? };
Ok(())
}
/// Read SPI flash JEDEC ID
pub fn jedec_id(&mut self) -> Result<u32, Error> {
let mut jedec = None;
unsafe {
self.in_ram(|| {
jedec.replace(ram_helpers::flash_jedec_id(true));
})?;
};
Ok(jedec.unwrap())
}
}
impl<'d, T: Instance, const FLASH_SIZE: usize> ErrorType for Flash<'d, T, FLASH_SIZE> {
@ -457,6 +474,220 @@ mod ram_helpers {
clobber_abi("C"),
);
}
#[repr(C)]
struct FlashCommand {
cmd_addr: *const u8,
cmd_addr_len: u32,
dummy_len: u32,
data: *mut u8,
data_len: u32,
}
/// Return SPI flash unique ID
///
/// Not all SPI flashes implement this command, so check the JEDEC
/// ID before relying on it. The Winbond parts commonly seen on
/// RP2040 devboards (JEDEC=0xEF7015) support an 8-byte unique ID;
/// https://forums.raspberrypi.com/viewtopic.php?t=331949 suggests
/// that LCSC (Zetta) parts have a 16-byte unique ID (which is
/// *not* unique in just its first 8 bytes),
/// JEDEC=0xBA6015. Macronix and Spansion parts do not have a
/// unique ID.
///
/// The returned bytes are relatively predictable and should be
/// salted and hashed before use if that is an issue (e.g. for MAC
/// addresses).
///
/// # Safety
///
/// Nothing must access flash while this is running.
/// Usually this means:
/// - interrupts must be disabled
/// - 2nd core must be running code from RAM or ROM with interrupts disabled
/// - DMA must not access flash memory
///
/// Credit: taken from `rp2040-flash` (also licensed Apache+MIT)
pub unsafe fn flash_unique_id(out: &mut [u8], use_boot2: bool) {
let mut boot2 = [0u32; 256 / 4];
let ptrs = if use_boot2 {
rom_data::memcpy44(&mut boot2 as *mut _, 0x10000000 as *const _, 256);
flash_function_pointers_with_boot2(false, false, &boot2)
} else {
flash_function_pointers(false, false)
};
// 4B - read unique ID
let cmd = [0x4B];
read_flash(&cmd[..], 4, out, &ptrs as *const FlashFunctionPointers);
}
/// Return SPI flash JEDEC ID
///
/// This is the three-byte manufacturer-and-model identifier
/// commonly used to check before using manufacturer-specific SPI
/// flash features, e.g. 0xEF7015 for Winbond W25Q16JV.
///
/// # Safety
///
/// Nothing must access flash while this is running.
/// Usually this means:
/// - interrupts must be disabled
/// - 2nd core must be running code from RAM or ROM with interrupts disabled
/// - DMA must not access flash memory
///
/// Credit: taken from `rp2040-flash` (also licensed Apache+MIT)
pub unsafe fn flash_jedec_id(use_boot2: bool) -> u32 {
let mut boot2 = [0u32; 256 / 4];
let ptrs = if use_boot2 {
rom_data::memcpy44(&mut boot2 as *mut _, 0x10000000 as *const _, 256);
flash_function_pointers_with_boot2(false, false, &boot2)
} else {
flash_function_pointers(false, false)
};
let mut id = [0u8; 4];
// 9F - read JEDEC ID
let cmd = [0x9F];
read_flash(&cmd[..], 0, &mut id[1..4], &ptrs as *const FlashFunctionPointers);
u32::from_be_bytes(id)
}
unsafe fn read_flash(cmd_addr: &[u8], dummy_len: u32, out: &mut [u8], ptrs: *const FlashFunctionPointers) {
read_flash_inner(
FlashCommand {
cmd_addr: cmd_addr.as_ptr(),
cmd_addr_len: cmd_addr.len() as u32,
dummy_len,
data: out.as_mut_ptr(),
data_len: out.len() as u32,
},
ptrs,
);
}
/// Issue a generic SPI flash read command
///
/// # Arguments
///
/// * `cmd` - `FlashCommand` structure
/// * `ptrs` - Flash function pointers as per `write_flash_inner`
///
/// Credit: taken from `rp2040-flash` (also licensed Apache+MIT)
#[inline(never)]
#[link_section = ".data.ram_func"]
unsafe fn read_flash_inner(cmd: FlashCommand, ptrs: *const FlashFunctionPointers) {
core::arch::asm!(
"mov r10, r0", // cmd
"mov r5, r1", // ptrs
"ldr r4, [r5, #0]",
"blx r4", // connect_internal_flash()
"ldr r4, [r5, #4]",
"blx r4", // flash_exit_xip()
"mov r7, r10", // cmd
"movs r4, #0x18",
"lsls r4, r4, #24", // 0x18000000, SSI, RP2040 datasheet 4.10.13
// Disable, write 0 to SSIENR
"movs r0, #0",
"str r0, [r4, #8]", // SSIENR
// Write ctrlr0
"movs r0, #0x3",
"lsls r0, r0, #8", // TMOD=0x300
"ldr r1, [r4, #0]", // CTRLR0
"orrs r1, r0",
"str r1, [r4, #0]",
// Write ctrlr1 with len-1
"ldr r0, [r7, #8]", // dummy_len
"ldr r1, [r7, #16]", // data_len
"add r0, r1",
"subs r0, #1",
"str r0, [r4, #0x04]", // CTRLR1
// Enable, write 1 to ssienr
"movs r0, #1",
"str r0, [r4, #8]", // SSIENR
// Write cmd/addr phase to DR
"mov r2, r4",
"adds r2, 0x60", // &DR
"ldr r0, [r7, #0]", // cmd_addr
"ldr r1, [r7, #4]", // cmd_addr_len
"10:",
"ldrb r3, [r0]",
"strb r3, [r2]", // DR
"adds r0, #1",
"subs r1, #1",
"bne 10b",
// Skip any dummy cycles
"ldr r1, [r7, #8]", // dummy_len
"cmp r1, #0",
"beq 9f",
"4:",
"ldr r3, [r4, #0x28]", // SR
"movs r2, #0x8",
"tst r3, r2", // SR.RFNE
"beq 4b",
"mov r2, r4",
"adds r2, 0x60", // &DR
"ldrb r3, [r2]", // DR
"subs r1, #1",
"bne 4b",
// Read RX fifo
"9:",
"ldr r0, [r7, #12]", // data
"ldr r1, [r7, #16]", // data_len
"2:",
"ldr r3, [r4, #0x28]", // SR
"movs r2, #0x8",
"tst r3, r2", // SR.RFNE
"beq 2b",
"mov r2, r4",
"adds r2, 0x60", // &DR
"ldrb r3, [r2]", // DR
"strb r3, [r0]",
"adds r0, #1",
"subs r1, #1",
"bne 2b",
// Disable, write 0 to ssienr
"movs r0, #0",
"str r0, [r4, #8]", // SSIENR
// Write 0 to CTRLR1 (returning to its default value)
//
// flash_enter_cmd_xip does NOT do this, and everything goes
// wrong unless we do it here
"str r0, [r4, #4]", // CTRLR1
"ldr r4, [r5, #20]",
"blx r4", // flash_enter_cmd_xip();
in("r0") &cmd as *const FlashCommand,
in("r1") ptrs,
out("r2") _,
out("r3") _,
out("r4") _,
// Registers r8-r10 are used to store values
// from r0-r2 in registers not clobbered by
// function calls.
// The values can't be passed in using r8-r10 directly
// due to https://github.com/rust-lang/rust/issues/99071
out("r8") _,
out("r9") _,
out("r10") _,
clobber_abi("C"),
);
}
}
mod sealed {

10
examples/rp/src/bin/flash.rs
View file

@ -24,6 +24,16 @@ async fn main(_spawner: Spawner) {
Timer::after(Duration::from_millis(10)).await;
let mut flash = embassy_rp::flash::Flash::<_, FLASH_SIZE>::new(p.FLASH);
// Get JEDEC id
let jedec = flash.jedec_id().unwrap();
info!("jedec id: 0x{:x}", jedec);
// Get unique id
let mut uid = [0; 8];
flash.unique_id(&mut uid).unwrap();
info!("unique id: {:?}", uid);
erase_write_sector(&mut flash, 0x00);
multiwrite_bytes(&mut flash, ERASE_SIZE as u32);