Previously, we always set the work buffer to 64 bytes, without
checking it was no less the actual program size. But we can't
simply switch to use the program size for the work buffer,
because if it's too small (e.g. 1 byte in some cases), we
will not be able to read the status header (24 bytes), and
small buffers means more underlying write operations and
lower efficiency.
This PR changes the work buffer size to be the program size,
or 64 bytes as an absolute minimum like before.
Previously, when writing a record header into a TDBStore, we
took the pointer to the record_header_t variable as the input,
but used a program-aligned chunk size which is larger.
As a result, garbage from the stack memory gets written.
This commit fixes that by buffering the record header.
Co-authored-by: Seppo Takalo <seppo.takalo@arm.com>
Add const to function declaration. Const objects cannot access const
safe functions, a compiler error is thrown if one tries to do so. This
helps ensure that the object calling the method will not be modified.
This is espescially desirable in functions where all we need to do is
query existing data and not make any alterations.
[Q/O/SPIFBlockDevice::erase() begin with an alignment check,
after which unaligned erases should not happen or be allowed.
If the erase address is not aligned to the value returned by
sfdp_iterate_next_largest_erase_type(), it indicates an
internal error in erase table parsing which should not be
hidden.
The test case set_add_data_set_key_value_five_Kbytes stores
5KB of value, and to allow for overheads, we allocate at least
8KB per area of TDBStore (so 16KB for two areas of a whole
TDBStore).
From the datasheet of the only OctaSPI flash we currently support
(http://www.mt-system.ru/sites/default/files/docs/Macronix/mx25lm51245g_3v_512mb_v0.01.pdf):
After program/erase command is issued, auto program/erase
algorithms which program/erase and verify the specified page
or sector/block locations will be executed. Program command is
executed on byte basis, or page (256 bytes) basis, or word basis.
Erase command is executed on sector (4K-byte), or block (64K-byte),
or whole chip basis.
So the minimum write size is one byte.
Prior to this PR, the minimum program size (QSPI_MIN_PROG_SIZE) of
QSPIFBlockDevice was 256 by default and 512 for some targets.
Those values were in fact page sizes, not program sizes.
Here's an explanation:
* Most QSPI flashes can be programmed to a granularity of a
single byte or a few bytes - no need to be a whole page.
This should be the value of QSPI_MIN_PROG_SIZE. Applications
need to align buffer sizes to this granularity when
programming QSPI flashes.
* Each sending of the underlying QSPI program signal requires
destination bytes to be located within the same page.
If a QSPIFBlockDevice::program() call crosses page boundaries,
this function breaks down the operation into multiple chunks,
so it's not a concern for the application.
So this PR changes the default program size to 1 (byte), and
for targets with a 4-byte (1-word) read size it overrides the
program size.
Note: No config is needed for the page size, as it comes from
the SFDP table parsed during initialisation.
Aside from the core mbed-os CMake target, a number of targets have been created so they can optionally be included by application executables that require them using `target_link_libraries()`.
Co-authored-by: Martin Kojtal <martin.kojtal@arm.com>
Co-authored-by: Rajkumar Kanagaraj <rajkumar.kanagaraj@arm.com>
Add license identifier to files which Arm owns the copyright to,
and contain either BSD-3 or Apache-2.0 licenses. This is to address
license errors raised by scancode analysis.
To allow overriding of the boot stack size from the Mbed configuration
system, consistently use MBED_CONF_TARGET_BOOT_STACK_SIZE rather than
MBED_BOOT_STACK_SIZE.
Fixes#10319
Martin Kojtal
Lingkai Dong
Harrison Mutai
jeromecoutant
Hugues Kamba
Hugues Kamba
Evelyne Donnaes
pea-pod
Bora Özgen
Rajkumar Kanagaraj
rogeryou
Gabor Toth
Jaeden Amero