DragonOS/kernel/syscall/syscall.c
2022-04-22 23:15:34 +08:00

128 lines
3.1 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#include "syscall.h"
#include "../process/process.h"
#include <exception/gate.h>
#include <exception/irq.h>
#include <driver/disk/ahci/ahci.h>
// 导出系统调用入口函数定义在entry.S中
extern void system_call(void);
extern void syscall_int(void);
/**
* @brief 导出系统调用处理函数的符号
*
*/
#define SYSCALL_COMMON(syscall_num, symbol) extern unsigned long symbol(struct pt_regs *regs);
SYSCALL_COMMON(0, system_call_not_exists); // 导出system_call_not_exists函数
#undef SYSCALL_COMMON // 取消前述宏定义
/**
* @brief 重新定义为:把系统调用函数加入系统调用表
* @param syscall_num 系统调用号
* @param symbol 系统调用处理函数
*/
#define SYSCALL_COMMON(syscall_num, symbol) [syscall_num] = symbol,
/**
* @brief sysenter的系统调用函数从entry.S中跳转到这里
*
* @param regs 3特权级下的寄存器值,rax存储系统调用号
* @return ul 对应的系统调用函数的地址
*/
ul system_call_function(struct pt_regs *regs)
{
return system_call_table[regs->rax](regs);
}
/**
* @brief 初始化系统调用模块
*
*/
void syscall_init()
{
kinfo("Initializing syscall...");
set_system_trap_gate(0x80, 0, syscall_int); // 系统调用门
}
/**
* @brief 通过中断进入系统调用
*
* @param syscall_id
* @param arg0
* @param arg1
* @param arg2
* @param arg3
* @param arg4
* @param arg5
* @param arg6
* @param arg7
* @return long
*/
long enter_syscall_int(ul syscall_id, ul arg0, ul arg1, ul arg2, ul arg3, ul arg4, ul arg5, ul arg6, ul arg7)
{
long err_code;
__asm__ __volatile__(
"movq %2, %%r8 \n\t"
"movq %3, %%r9 \n\t"
"movq %4, %%r10 \n\t"
"movq %5, %%r11 \n\t"
"movq %6, %%r12 \n\t"
"movq %7, %%r13 \n\t"
"movq %8, %%r14 \n\t"
"movq %9, %%r15 \n\t"
"int $0x80 \n\t"
: "=a"(err_code)
: "a"(syscall_id), "m"(arg0), "m"(arg1), "m"(arg2), "m"(arg3), "m"(arg4), "m"(arg5), "m"(arg6), "m"(arg7)
: "memory", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "rcx", "rdx");
return err_code;
}
/**
* @brief 打印字符串的系统调用
*
* 当arg1和arg2均为0时打印黑底白字否则按照指定的前景色和背景色来打印
*
* @param regs 寄存器
* @param arg0 要打印的字符串
* @param arg1 前景色
* @param arg2 背景色
* @return ul 返回值
*/
ul sys_printf(struct pt_regs *regs)
{
if (regs->r9 == 0 && regs->r10 == 0)
printk((char *)regs->r8);
else
printk_color(regs->r9, regs->r10, (char *)regs->r8);
// printk_color(BLACK, WHITE, (char *)regs->r8);
return 0;
}
ul sys_ahci_end_req(struct pt_regs *regs)
{
ahci_end_request();
return 0;
}
// 系统调用的内核入口程序
void do_syscall_int(struct pt_regs *regs, unsigned long error_code)
{
ul ret = system_call_table[regs->rax](regs);
regs->rax = ret; // 返回码
}
system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] =
{
[0] = system_call_not_exists,
[1] = sys_printf,
[2 ... 254] = system_call_not_exists,
[255] = sys_ahci_end_req};