interesting
/
riscv-openocd
mirror of https://github.com/riscv/riscv-openocd.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

NOR/CFI: identify memory accesses not using "bus_width". 

Since NOR flash devices does not handle "byte enable lanes",
each read/write access involves the whole "chip_width".
When multiple devices are in parallel, usually all chips are
enabled during each access.
All such cases are compatible with flash accesses at
"bus_width" size.

Access at "bus_width" size is mandatory for write access to
avoid transferring of garbage values to flash.
During read access the flash controller should take care,
and discard unneeded bytes. Anyway, it is good practice to
use "bus_width" size also for read.

Every memory access that does not respect "bus_width" size
is marked with a "FIXME" comment.

Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
This commit is contained in:
Antonio Borneo 2010-04-20 12:15:49 +08:00 committed by Øyvind Harboe
parent 89747f81f2
commit 61bb0d3d23
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/flash/nor/cfi.c
View File

@ -1871,6 +1871,7 @@ static int cfi_write(struct flash_bank *bank, uint8_t *buffer, uint32_t offset,
for (i = 0; i < align; ++i, ++copy_p)
{
uint8_t byte;
/* FIXME: access flash at bus_width size */
if ((retval = target_read_memory(target, copy_p, 1, 1, &byte)) != ERROR_OK)
{
return retval;
@ -1890,6 +1891,7 @@ static int cfi_write(struct flash_bank *bank, uint8_t *buffer, uint32_t offset,
for (; (count == 0) && (i < bank->bus_width); ++i, ++copy_p)
{
uint8_t byte;
/* FIXME: access flash at bus_width size */
if ((retval = target_read_memory(target, copy_p, 1, 1, &byte)) != ERROR_OK)
{
return retval;
@ -2005,6 +2007,7 @@ static int cfi_write(struct flash_bank *bank, uint8_t *buffer, uint32_t offset,
for (; i < bank->bus_width; ++i, ++copy_p)
{
uint8_t byte;
/* FIXME: access flash at bus_width size */
if ((retval = target_read_memory(target, copy_p, 1, 1, &byte)) != ERROR_OK)
{
return retval;
@ -2137,10 +2140,12 @@ static int cfi_probe(struct flash_bank *bank)
if (bank->chip_width == 1)
{
uint8_t manufacturer, device_id;
/* FIXME: access flash at bus_width size */
if ((retval = target_read_u8(target, flash_address(bank, 0, 0x00), &manufacturer)) != ERROR_OK)
{
return retval;
}
/* FIXME: access flash at bus_width size */
if ((retval = target_read_u8(target, flash_address(bank, 0, 0x01), &device_id)) != ERROR_OK)
{
return retval;
@ -2150,10 +2155,12 @@ static int cfi_probe(struct flash_bank *bank)
}
else if (bank->chip_width == 2)
{
/* FIXME: access flash at bus_width size */
if ((retval = target_read_u16(target, flash_address(bank, 0, 0x00), &cfi_info->manufacturer)) != ERROR_OK)
{
return retval;
}
/* FIXME: access flash at bus_width size */
if ((retval = target_read_u16(target, flash_address(bank, 0, 0x01), &cfi_info->device_id)) != ERROR_OK)
{
return retval;
@ -2543,6 +2550,7 @@ struct flash_driver cfi_flash = {
.write = cfi_write,
.probe = cfi_probe,
.auto_probe = cfi_auto_probe,
/* FIXME: access flash at bus_width size */
.erase_check = default_flash_blank_check,
.protect_check = cfi_protect_check,
.info = cfi_info,