Hi,
I'm interested in reading and writing to the status register in much the same way as the ChomiumOS flashrom do with it's --wp-* commands. But in a more generic way say:
--sr-read --sr-write 0xAA
I'm thinking of this implementation: - Porting ChomiumOS writeprotect.c to flashrom - Implement a pure read/write of status register - Change the --wp-* commands to use the status register read/write functions
Is this anything the flashrom community is interested in? I'd love to get feedback on this. My knowledge of flashroms structure is not as comprehensive yet so suggestions on implementation is appreciated.
The porting of the ChomiumOS flashrom --wp-* is not necessary for my goal but I though it might be the right path to go for flashrom, please correct me if I'm wrong.
-- Best Regards // Niklas
On Mon, Apr 2, 2012 at 1:01 AM, Niklas Söderlund < niklas.soderlund@ericsson.com> wrote:
I can see how this would be handy for people who really know what they're doing. OTOH, please be aware that status register layout, especially with regard to block protection, is rather inconsistent. If you have scripts that rely on a specific register layout it will likely break when you switch chips. It would help to know exactly what you're trying to accomplish so that we can tell if it's really necessary (or even a good idea) to operate on the raw status register content.
Be advised that some newer SPI chips also have a second status register. LPC chips have a status register (or at least some do... I'm looking at the SST49LF016 datasheet), but the information provided is quite a bit different from what's to be expected on SPI chips.
For the Chrome/Chromium OS branch, we were really only trying to make a script-able interface for write-protecting regions of 25-series SPI flash. So for example, a script could write-protect the bottom half the chip by doing something like: flashrom --wp-range 0 $(($(flashrom --chip-size)/2)) --wp-enable
More food for thought on the subject of write-protection: http://www.flashrom.org/pipermail/flashrom/2011-February/005795.html . One issue we found is that 25-series and 26-series SPI chips tend to have drastically different block protection capabilities. 25-series chips usually have uniform block protection, where by you block protect 1/Nth the size of the chip, while 26-series is much more flexible. Supporting all the different variations presenting them to the user in a sane manner takes some thought.
After a discussion on IRC it was brought up that vanilla flashrom in the past disagreed with the ChromiumOS implementation of the --wp-* operations. In light of this I have dropped this from my implementation and only done the parts I'm really interested in, raw access to the status register.
Please let me know where I can improve it and if there is any interest at all from flashrom to include such a feature.
When working with a lot of different flash chips it's sometimes useful to be able to print and update the status register directly as a separate operation.
Add --print-status and --write-status command line options to that maps to spi_read_status_register and spi_write_status_register.
The print operation reads the status register and prints it content to the user. While the write operation takes a parameter as a hex value (0x00 to 0xff) or a decimal value (0 to 255) and tries to write it to the status register.
This operation is limited to flash chips that have a SPI bustype.
Signed-off-by: Niklas Söderlund niklas.soderlund@ericsson.com --- cli_classic.c | 37 ++++++++++++++++++++++++++++++++----- flash.h | 2 +- flashrom.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 81 insertions(+), 7 deletions(-)
diff --git a/cli_classic.c b/cli_classic.c index 972043b..87af1f3 100644 --- a/cli_classic.c +++ b/cli_classic.c @@ -144,11 +144,17 @@ static void cli_classic_usage(const char *name) "device\n");
list_programmers_linebreak(37, 80, 1); + + printf("\nAdvance options (use at your own risk)\n" + " -P | --print-status print status register\n" + " -W | --write-status <value> write <value> to status " + "register\n"); + printf("\nYou can specify one of -h, -R, -L, " #if CONFIG_PRINT_WIKI == 1 "-z, " #endif - "-E, -r, -w, -v or no operation.\n" + "-E, -r, -w, -v -P, -W or no operation.\n" "If no operation is specified, flashrom will only probe for " "flash chips.\n\n"); } @@ -173,15 +179,18 @@ int main(int argc, char *argv[]) int list_supported_wiki = 0; #endif int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0; + int statusreg_op = 0; int dont_verify_it = 0, list_supported = 0, operation_specified = 0; enum programmer prog = PROGRAMMER_INVALID; int ret = 0;
- static const char optstring[] = "r:Rw:v:nVEfc:l:i:p:Lzh"; + static const char optstring[] = "r:Rw:v:nVEfc:l:i:p:LzhPW:"; static const struct option long_options[] = { {"read", 1, NULL, 'r'}, {"write", 1, NULL, 'w'}, {"erase", 0, NULL, 'E'}, + {"print-status", 0, NULL, 'P'}, + {"write-status", 1, NULL, 'W'}, {"verify", 1, NULL, 'v'}, {"noverify", 0, NULL, 'n'}, {"chip", 1, NULL, 'c'}, @@ -201,6 +210,7 @@ int main(int argc, char *argv[]) char *layoutfile = NULL; char *tempstr = NULL; char *pparam = NULL; + char *statusreg_value = NULL;
print_version(); print_banner(); @@ -270,6 +280,23 @@ int main(int argc, char *argv[]) } erase_it = 1; break; + case 'P': + if (++operation_specified > 1) { + fprintf(stderr, "More than one operation " + "specified. Aborting.\n"); + cli_classic_abort_usage(); + } + statusreg_op = 1; + break; + case 'W': + if (++operation_specified > 1) { + fprintf(stderr, "More than one operation " + "specified. Aborting.\n"); + cli_classic_abort_usage(); + } + statusreg_op = 1; + statusreg_value = strdup(optarg); + break; case 'f': force = 1; break; @@ -511,12 +538,12 @@ int main(int argc, char *argv[]) goto out_shutdown; }
- if (!(read_it | write_it | verify_it | erase_it)) { + if (!(read_it | write_it | verify_it | erase_it | statusreg_op)) { printf("No operations were specified.\n"); goto out_shutdown; }
- if (!filename && !erase_it) { + if (!filename && !erase_it && !statusreg_op) { printf("Error: No filename specified.\n"); ret = 1; goto out_shutdown; @@ -531,7 +558,7 @@ int main(int argc, char *argv[]) * Give the chip time to settle. */ programmer_delay(100000); - return doit(fill_flash, force, filename, read_it, write_it, erase_it, verify_it); + return doit(fill_flash, force, filename, read_it, write_it, erase_it, verify_it, statusreg_op, statusreg_value);
out_shutdown: programmer_shutdown(); diff --git a/flash.h b/flash.h index 0dac13d..65ee0af 100644 --- a/flash.h +++ b/flash.h @@ -247,7 +247,7 @@ void print_version(void); void print_banner(void); void list_programmers_linebreak(int startcol, int cols, int paren); int selfcheck(void); -int doit(struct flashctx *flash, int force, const char *filename, int read_it, int write_it, int erase_it, int verify_it); +int doit(struct flashctx *flash, int force, const char *filename, int read_it, int write_it, int erase_it, int verify_it, int statureg_op, const char *statusreg_op); int read_buf_from_file(unsigned char *buf, unsigned long size, const char *filename); int write_buf_to_file(unsigned char *buf, unsigned long size, const char *filename);
diff --git a/flashrom.c b/flashrom.c index cad043b..b3ba376 100644 --- a/flashrom.c +++ b/flashrom.c @@ -31,12 +31,14 @@ #include <stdlib.h> #include <ctype.h> #include <getopt.h> +#include <errno.h> #if HAVE_UTSNAME == 1 #include <sys/utsname.h> #endif #include "flash.h" #include "flashchips.h" #include "programmer.h" +#include "chipdrivers.h"
const char flashrom_version[] = FLASHROM_VERSION; char *chip_to_probe = NULL; @@ -1396,6 +1398,45 @@ int erase_and_write_flash(struct flashctx *flash, uint8_t *oldcontents, return ret; }
+int operate_on_statusregister(struct flashctx *flash, const char* value) { + long status; + char *endptr; + + if (flash->bustype != BUS_SPI) { + msg_cerr("Flash is not on SPI bus. Can't operate on status register\n"); + return 1; + } + + if (value) { + /* Try to parse as hex then dec */ + errno = 0; + status = strtol(value, &endptr, 0); + if (endptr == value || *endptr != '\0' || errno != 0) { + msg_cerr("Error parsing value %s for status register\n", + value); + return 1; + } + + if (status < 0 || status > 0xFF) { + msg_cerr("Invalid status register value: %s\n", value); + return 1; + } + + if (spi_write_status_register(flash, status)) { + msg_cerr("spi_write_status_register failed\n"); + return 1; + } + + msg_cinfo("Wrote 0x%02lx to status register\n", status); + } + + /* Read and print current value */ + status = spi_read_status_register(flash); + msg_cinfo("Status register: 0x%02lx\n", status); + + return 0; +} + void nonfatal_help_message(void) { msg_gerr("Writing to the flash chip apparently didn't do anything.\n" @@ -1705,7 +1746,8 @@ int chip_safety_check(struct flashctx *flash, int force, int read_it, * Besides that, the function itself is a textbook example of abysmal code flow. */ int doit(struct flashctx *flash, int force, const char *filename, int read_it, - int write_it, int erase_it, int verify_it) + int write_it, int erase_it, int verify_it, + int statusreg_op, const char *statusreg_value) { uint8_t *oldcontents; uint8_t *newcontents; @@ -1718,6 +1760,11 @@ int doit(struct flashctx *flash, int force, const char *filename, int read_it, goto out_nofree; }
+ if (statusreg_op) { + ret = operate_on_statusregister(flash, statusreg_value); + goto out_nofree; + } + /* Given the existence of read locks, we want to unlock for read, * erase and write. */
-
David Hendricks -
Niklas Söderlund