[U-Boot] [PATCH] pxe: Allow use of environment variables in append string
Use run_command("setenv bootargs <label->append>") so that environment variables (e.g. $console) can be used in append strings.
Signed-off-by: Hans de Goede hdegoede@redhat.com --- common/cmd_pxe.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c index ba48692..3866604 100644 --- a/common/cmd_pxe.c +++ b/common/cmd_pxe.c @@ -571,14 +571,23 @@ static void label_print(void *data) static int label_localboot(struct pxe_label *label) { char *localcmd; + char *bootargs;
localcmd = from_env("localcmd");
if (!localcmd) return -ENOENT;
- if (label->append) - setenv("bootargs", label->append); + if (label->append) { + bootargs = malloc(strlen("setenv bootargs ") + + strlen(label->append) + 1); + if (!bootargs) + return 1; + strcpy(bootargs, "setenv bootargs "); + strcat(bootargs, label->append); + run_command(bootargs, 0); + free(bootargs); + }
debug("running: %s\n", localcmd);
@@ -669,17 +678,17 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label) len += strlen(label->append);
if (len) { - bootargs = malloc(len + 1); + bootargs = malloc(strlen("setenv bootargs ") + len + 1); if (!bootargs) return 1; - bootargs[0] = '\0'; + strcpy(bootargs, "setenv bootargs "); if (label->append) - strcpy(bootargs, label->append); + strcat(bootargs, label->append); strcat(bootargs, ip_str); strcat(bootargs, mac_str);
- setenv("bootargs", bootargs); - printf("append: %s\n", bootargs); + run_command(bootargs, 0); + printf("append: %s\n", getenv("bootargs"));
free(bootargs); }
On 08/01/2014 03:21 AM, Hans de Goede wrote:
Use run_command("setenv bootargs <label->append>") so that environment variables (e.g. $console) can be used in append strings.
I'm slightly worried that this changes the semantics of the append line in the PXE/extlinux config file. Namely, you suddenly have to start worrying about escaping any $ signs or semi-colons etc..
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c
if (!localcmd) return -ENOENT;
- if (label->append)
setenv("bootargs", label->append);
- if (label->append) {
bootargs = malloc(strlen("setenv bootargs ") +strlen(label->append) + 1);if (!bootargs)return 1;
Shouldn't this return a -ve error code for consistency with the other pre-existing error case I quoted above.
strcpy(bootargs, "setenv bootargs ");strcat(bootargs, label->append);run_command(bootargs, 0);
Using whatever C function that the shell uses to expand variable references in the command-line, rather than run_command(), would at least avoid the issue of ; in label->append causing part of label->append after the ; to be execututed as a separate command.
There would still be the issue of $ suddenly meaning something different.
Hi,
On 08/01/2014 09:07 PM, Stephen Warren wrote:
On 08/01/2014 03:21 AM, Hans de Goede wrote:
Use run_command("setenv bootargs <label->append>") so that environment variables (e.g. $console) can be used in append strings.
I'm slightly worried that this changes the semantics of the append line in the PXE/extlinux config file. Namely, you suddenly have to start worrying about escaping any $ signs or semi-colons etc..
I'm not that worried about $ needing escaping, as I cannot think of any kernel commandline options using $, maybe they exist but if they do they are quite rare.
But you make a good point about the ; I know some kernel cmdline options which use those...
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c
if (!localcmd) return -ENOENT;
- if (label->append)
setenv("bootargs", label->append);
- if (label->append) {
bootargs = malloc(strlen("setenv bootargs ") +strlen(label->append) + 1);if (!bootargs)return 1;Shouldn't this return a -ve error code for consistency with the other pre-existing error case I quoted above.
Yeah this is weird, I copy pasted this from the label_boot() function, of which is a special version, also label_boot() is the only caller of label_localboot() (where this hunk applies), and it does not check the return value at all...
I could make it -ENOMEM if you prefer.
strcpy(bootargs, "setenv bootargs ");strcat(bootargs, label->append);run_command(bootargs, 0);Using whatever C function that the shell uses to expand variable references in the command-line, rather than run_command(), would at least avoid the issue of ; in label->append causing part of label->append after the ; to be execututed as a separate command.
Ack, I'll look into that and post a v2 with that change.
There would still be the issue of $ suddenly meaning something different.
Right, but as said I'm not really worried about that.
Regards,
Hans
participants (2)
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Hans de Goede -
Stephen Warren