mirror of
https://github.com/drasko/codezero.git
synced 2026-01-13 19:33:15 +01:00
40e088b042
- Added a full ipc send/recv test - Removed non-zero value checking in r2 for ipc that was there to catch inadvertent full ipc calls. - Added correct hanlding for read/write mrs for current status of utcb. TODO: - Add mapping of every utcb to every task for privileged access so that the kernel can access every utcb without switching spaces. - Removal of same mappings - Upon thread creation need to copy page tables accordingly i.e. each task will have its own utcb mapped with USER access, but every other utcb as kernel access only. Need to handle this case upon page table copying.
96 lines
3.9 KiB
C
96 lines
3.9 KiB
C
/*
|
|
* Userspace thread control block
|
|
*
|
|
* Copyright (C) 2007-2009 Bahadir Bilgehan Balban
|
|
*/
|
|
#ifndef __GLUE_ARM_MESSAGE_H__
|
|
#define __GLUE_ARM_MESSAGE_H__
|
|
|
|
/*
|
|
* Here's a summary of how ARM registers are used during IPC:
|
|
*
|
|
* System registers:
|
|
* r0 - r2: Passed as arguments to ipc() call. They are the registers
|
|
* the microkernel will read and they have system-wide meaning.
|
|
*
|
|
* Primary message registers:
|
|
* r3 - r8: These 6 registers are the primary message registers MR0-MR6
|
|
* Their format is application-specific, i.e. the microkernel imposes no
|
|
* format restrictions on them.
|
|
*
|
|
* TODO: The only exception is that, for ANYTHREAD receivers the predefined
|
|
* MR_SENDER is touched by the kernel to indicate the sender. This register
|
|
* is among the primary MRs and it may be better fit to put it into one of
|
|
* the system registers.
|
|
*
|
|
* l4lib registers: (MR_TAG, MR_SENDER, MR_RETURN)
|
|
* Some of the primary message registers are used by the l4lib convenience
|
|
* library for operations necessary on most or all common ipcs. For example
|
|
* every ipc has a tag that specifies the ipc reason. Also send/receive
|
|
* operations require a return value. Threads that are open to receive from
|
|
* all threads require the sender id. These values are passed in predefined
|
|
* primary message registers, but the microkernel has no knowledge about them.
|
|
*
|
|
* System call registers: L4SYS_ARG0 to ARG4.(See syslib.h for definitions)
|
|
* Finally the rest of the primary message registers are available for
|
|
* implementing system call arguments. For example the POSIX services use
|
|
* these arguments to pass posix system call information.
|
|
*
|
|
* Secondary Message Registers:
|
|
* These are non-real registers and are present in the UTCB memory region.
|
|
* Both real and non-real message registers have a location in the UTCB, but
|
|
* non-real ones are copied only if the FULL IPC flag is set.
|
|
*
|
|
* The big picture:
|
|
*
|
|
* r0 System register
|
|
* r1 System register
|
|
* r2 System register
|
|
* r3 Primary MR0 MR_RETURN, MR_TAG Present in UTCB, Short IPC
|
|
* r4 Primary MR1 MR_SENDER Present in UTCB, Short IPC
|
|
* r5 Primary MR2 L4SYS_ARG0 Present in UTCB, Short IPC
|
|
* r6 Primary MR3 L4SYS_ARG1 Present in UTCB, Short IPC
|
|
* r7 Primary MR4 L4SYS_ARG2 Present in UTCB, Short IPC
|
|
* r8 Primary MR5 L4SYS_ARG3 Present in UTCB, Short IPC
|
|
* x Secondary MR6 Present in UTCB, Full IPC only
|
|
* x Secondary MR64 Present in UTCB, Full IPC only
|
|
*
|
|
* Complicated for you? Suggest a simpler design and it shall be implemented!
|
|
*/
|
|
|
|
#define MR_REST ((UTCB_SIZE >> 2) - MR_TOTAL - 2) /* -2 is for fields on utcb */
|
|
#define MR_TOTAL 6
|
|
#define MR_TAG 0 /* Contains the purpose of message */
|
|
#define MR_SENDER 1 /* For anythread receivers to discover sender */
|
|
#define MR_RETURN 0 /* Contains the posix return value. */
|
|
|
|
/* These define the mr start - end range that isn't used by userspace syslib */
|
|
#define MR_UNUSED_START 2 /* The first mr that's not used by syslib.h */
|
|
#define MR_UNUSED_TOTAL (MR_TOTAL - MR_UNUSED_START)
|
|
#define MR_USABLE_TOTAL MR_UNUSED_TOTAL
|
|
|
|
/* These are defined so that we don't hard-code register names */
|
|
#define MR0_REGISTER r3
|
|
#define MR_RETURN_REGISTER r3
|
|
|
|
#define L4_IPC_FLAGS_FULL 0x00000001 /* Full IPC involves full UTCB copy */
|
|
#define L4_IPC_FLAGS_EXTENDED 0x00000002 /* Extended IPC can page-fault and copy up to 2KB */
|
|
#define L4_IPC_FLAGS_MSG_INDEX_MASK 0x00000FF0 /* Index of message register with buffer pointer */
|
|
#define L4_IPC_FLAGS_MASK 0x0000000F
|
|
#define L4_IPC_FLAGS_SIZE_MASK 0x0FFF0000
|
|
#define L4_IPC_FLAGS_SIZE_SHIFT 16
|
|
#define L4_IPC_FLAGS_MSG_INDEX_SHIFT 4
|
|
|
|
#include INC_GLUE(memlayout.h)
|
|
|
|
#if defined (__KERNEL__)
|
|
struct utcb {
|
|
u32 mr[MR_TOTAL]; /* MRs that are mapped to real registers */
|
|
u32 saved_tag; /* Saved tag field for stacked ipcs */
|
|
u32 saved_sender; /* Saved sender field for stacked ipcs */
|
|
u32 mr_rest[MR_REST]; /* Complete the utcb for up to 64 words */
|
|
};
|
|
#endif
|
|
|
|
#endif /* __GLUE_ARM_MESSAGE_H__ */
|