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3ce220f062
This copies the parent kernel stack to child only for the part where the previous context is saved. Then the child registers are modified so that it would begin execution from returning of the system call.
68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/*
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* ARM-specific system call details.
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*
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* Copyright (C) 2007 Bahadir Balban
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*
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*/
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#ifndef __ARM_GLUE_SYSCALL_H__
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#define __ARM_GLUE_SYSCALL_H__
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/* Only specific call is the trap that gives back the kip address
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* from which other system calls can be discovered. */
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#define L4_TRAP_KIP 0xB4
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/* Used in the kernel to refer to virtual address of this page.
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* User space discovers it from the KIP */
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#define ARM_SYSCALL_PAGE 0xFFFFF000
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extern unsigned int __syscall_page_start;
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/*
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* This structure is saved on the kernel stack
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* just after entering a system call exception.
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*/
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typedef struct syscall_context {
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u32 spsr
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u32 r0;
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u32 r1;
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u32 r2;
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u32 r3; /* MR0 */
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u32 r4; /* MR1 */
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u32 r5; /* MR2 */
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u32 r6; /* MR3 */
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u32 r7; /* MR4 */
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u32 r8; /* MR5 */
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u32 sp_usr;
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u32 lr_usr;
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} __attribute__((__packed__)) syscall_context_t;
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typedef struct msg_regs {
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u32 mr0;
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u32 mr1;
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u32 mr2;
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u32 mr3;
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u32 mr4;
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u32 mr5;
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} msg_regs_t;
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/* NOTE:
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* These references are valid only when they have been explicitly set
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* by a kernel entry point, e.g. a system call, a data abort handler.
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*/
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#define KTCB_REF_ARG0(ktcb) (&(ktcb)->syscall_regs->r0)
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#define KTCB_REF_MR0(ktcb) (&(ktcb)->syscall_regs->r3)
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/* Represents each syscall. We get argument registers
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* from stack for now. This is slower but the simplest. */
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typedef int (*syscall_fn_t)(struct syscall_args *regs);
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/* Entry point for syscall dispatching. Called from asm */
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int syscall(struct syscall_args *regs, unsigned long);
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/* Syscall-related initialiser called during system init. */
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void syscall_init(void);
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void kip_init_syscalls(void);
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#endif /* __ARM_GLUE_SYSCALL_H__ */
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