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+# PCB
+
+PCB information
+
+## context
+
+Contains context infromation for the curernt process.
+- memory context (pcb->memctx)
+  - stores page directory and vitural address allocateor (see MEMORY.md)
+- context save area (pcb->regs)
+
+## medatada
+
+- `pid` - process idenfitication number
+- `parent` ` - parent of the current process
+  - can be NULL if the init process
+- `state` - the current runing state of the process
+  - `UNUSED` - proces in ptable is not used
+  - `NEW` - process in ptable has been allocated but has not been initalized
+  - `READY` - process is ready to be dispatched (and in ready queue)
+  - `RUNNING` - process is the current running process (and in no queues)
+  - `BLOCKED` - process is in a syscall queue waiting on their syscall to return
+  - `ZOMBIE` - process is a zombie and waiting to be cleaned up (in zombie queue)
+- `priority` - running process priority
+  - any number form 0 to SIZET_MAX
+  - higher priority means longer wait to be scheduled
+- `ticks` - number of ticks the process has been running for
+  - set to zero when process is not running
+
+## heap
+
+- `heap_start` is the start of the progams heap
+- `heap_len` is the length of the programs heap
+
+## open files
+
+- `open_files` is a list of currently opened files indexed by file descriptor
+
+## elf metadata
+
+- `elf_header` - the programs elf header (Elf64_Ehdr)
+- `elf_segments` - the programs loadable elf segments (Elf64_Phdr[])
+- `n_elf_segments` - the number of elf segmsnts the program has
+
+## queue linkage
+
+- `next` - the next pcb in the current queue this pcb is in
+
+## processs state information
+
+- `syscall` - the current syscall this process is blocked on
+- `wakeup` - the number of ticks until the process can be waked up (used during SYS_sleep)
+- `exit_status` - the exit status of the process when a zombie