diff options
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_environment.c | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/sys/kern/kern_environment.c b/sys/kern/kern_environment.c index ff453cb..05c4f62 100644 --- a/sys/kern/kern_environment.c +++ b/sys/kern/kern_environment.c @@ -210,12 +210,44 @@ done: return (error); } +/* + * Populate the initial kernel environment. + * + * This is called very early in MD startup, either to provide a copy of the + * environment obtained from a boot loader, or to provide an empty buffer into + * which MD code can store an initial environment using kern_setenv() calls. + * + * If the global envmode is 1, the environment is initialized from the global + * static_env[], regardless of the arguments passed. This implements the env + * keyword described in config(5). In this case env_pos is set to env_len, + * causing kern_setenv() to return -1 (if len > 0) or panic (if len == 0) until + * the dynamic environment is available. The envmode and static_env variables + * are defined in env.c which is generated by config(8). + * + * If len is non-zero, the caller is providing an empty buffer. The caller will + * subsequently use kern_setenv() to add up to len bytes of initial environment + * before the dynamic environment is available. + * + * If len is zero, the caller is providing a pre-loaded buffer containing + * environment strings. Additional strings cannot be added until the dynamic + * environment is available. The memory pointed to must remain stable at least + * until sysinit runs init_dynamic_kenv(). If no initial environment is + * available from the boot loader, passing a NULL pointer allows the static_env + * to be installed if it is configured. + */ void init_static_kenv(char *buf, size_t len) { - kern_envp = buf; - env_len = len; - env_pos = 0; + + if (envmode == 1) { + kern_envp = static_env; + env_len = len; + env_pos = len; + } else { + kern_envp = buf; + env_len = len; + env_pos = 0; + } } /* |
