[dmidecode] [PATCH 4/4] Add --no-sysfs option to disable use of sysfs

[Roy Franz]

This option forces any SMBIOS information in sysfs to be ignored, resulting
in dmidecode using /dev/mem for SMBIOS access.  This is likely most useful
for debugging.

Signed-off-by: Roy Franz <address@hidden>
---
 dmidecode.c | 3 ++-
 dmiopt.c    | 6 +++++-
 dmiopt.h    | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/dmidecode.c b/dmidecode.c
index ef4259d..fb0ef70 100644
--- a/dmidecode.c
+++ b/dmidecode.c
@@ -4681,7 +4681,8 @@ int main(int argc, char * const argv[])
         * contain one of several types of entry points, so read enough for
         * the largest one, then determine what type it contains.
         */
-       if ((buf = read_file(0x20, SYS_ENTRY_FILE)) != NULL)
+       if (!(opt.flags & FLAG_NO_SYSFS)
+           && (buf = read_file(0x20, SYS_ENTRY_FILE)) != NULL)
        {
                printf("Getting SMBIOS data from sysfs\n");
                if (memcmp(buf, "_DMI_", 5) == 0)
diff --git a/dmiopt.c b/dmiopt.c
index 1c56a0e..e89ee8a 100644
--- a/dmiopt.c
+++ b/dmiopt.c
@@ -215,7 +215,7 @@ static int parse_opt_string(const char *arg)
 int parse_command_line(int argc, char * const argv[])
 {
        int option;
-       const char *optstring = "d:hqs:t:uV";
+       const char *optstring = "d:hqs:t:uVn";
        struct option longopts[] = {
                { "dev-mem", required_argument, NULL, 'd' },
                { "help", no_argument, NULL, 'h' },
@@ -226,6 +226,7 @@ int parse_command_line(int argc, char * const argv[])
                { "dump-bin", required_argument, NULL, 'B' },
                { "from-dump", required_argument, NULL, 'F' },
                { "version", no_argument, NULL, 'V' },
+               { "no-sysfs", no_argument, NULL, 'n' },
                { 0, 0, 0, 0 }
        };
 
@@ -265,6 +266,9 @@ int parse_command_line(int argc, char * const argv[])
                        case 'V':
                                opt.flags |= FLAG_VERSION;
                                break;
+                       case 'n':
+                               opt.flags |= FLAG_NO_SYSFS;
+                               break;
                        case '?':
                                switch (optopt)
                                {
diff --git a/dmiopt.h b/dmiopt.h
index b7f2533..5f3103c 100644
--- a/dmiopt.h
+++ b/dmiopt.h
@@ -42,6 +42,7 @@ extern struct opt opt;
 #define FLAG_QUIET              (1 << 3)
 #define FLAG_DUMP_BIN           (1 << 4)
 #define FLAG_FROM_DUMP          (1 << 5)
+#define FLAG_NO_SYSFS           (1 << 6)
 
 int parse_command_line(int argc, char * const argv[]);
 void print_help(void);
-- 
1.9.1