60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/* See COPYRIGHT for copyright information. */
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#ifndef JOS_INC_ENV_H
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#define JOS_INC_ENV_H
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#include <inc/types.h>
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#include <inc/trap.h>
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#include <inc/memlayout.h>
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typedef int32_t envid_t;
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// An environment ID 'envid_t' has three parts:
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//
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// +1+---------------21-----------------+--------10--------+
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// |0| Uniqueifier | Environment |
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// | | | Index |
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// +------------------------------------+------------------+
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// \--- ENVX(eid) --/
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//
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// The environment index ENVX(eid) equals the environment's index in the
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// 'envs[]' array. The uniqueifier distinguishes environments that were
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// created at different times, but share the same environment index.
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//
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// All real environments are greater than 0 (so the sign bit is zero).
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// envid_ts less than 0 signify errors. The envid_t == 0 is special, and
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// stands for the current environment.
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#define LOG2NENV 10
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#define NENV (1 << LOG2NENV)
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#define ENVX(envid) ((envid) & (NENV - 1))
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// Values of env_status in struct Env
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enum {
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ENV_FREE = 0,
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ENV_DYING,
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ENV_RUNNABLE,
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ENV_RUNNING,
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ENV_NOT_RUNNABLE
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};
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// Special environment types
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enum EnvType {
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ENV_TYPE_USER = 0,
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};
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struct Env {
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struct Trapframe env_tf; // Saved registers
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struct Env *env_link; // Next free Env
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envid_t env_id; // Unique environment identifier
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envid_t env_parent_id; // env_id of this env's parent
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enum EnvType env_type; // Indicates special system environments
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unsigned env_status; // Status of the environment
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uint32_t env_runs; // Number of times environment has run
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// Address space
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pde_t *env_pgdir; // Kernel virtual address of page dir
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};
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#endif // !JOS_INC_ENV_H
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