monitor.c

// Simple command-line kernel monitor useful for
// controlling the kernel and exploring the system interactively.

#include <inc/stdio.h>
#include <inc/string.h>
#include <inc/memlayout.h>
#include <inc/assert.h>
#include <inc/x86.h>

#include <kern/console.h>
#include <kern/monitor.h>
#include <kern/kdebug.h>

#define CMDBUF_SIZE	80	// enough for one VGA text line


struct Command {
	const char *name;
	const char *desc;
	// return -1 to force monitor to exit
	int (*func)(int argc, char** argv, struct Trapframe* tf);
};

static struct Command commands[] = {
	{ "help", "Display this list of commands", mon_help },
	{ "kerninfo", "Display information about the kernel", mon_kerninfo },
};

/***** Implementations of basic kernel monitor commands *****/

int
mon_help(int argc, char **argv, struct Trapframe *tf)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(commands); i++)
		cprintf("%s - %s\n", commands[i].name, commands[i].desc);
	return 0;
}

int
mon_kerninfo(int argc, char **argv, struct Trapframe *tf)
{
	extern char _start[], entry[], etext[], edata[], end[];

	cprintf("Special kernel symbols:\n");
	cprintf("  _start                  %08x (phys)\n", _start);
	cprintf("  entry  %08x (virt)  %08x (phys)\n", entry, entry - KERNBASE);
	cprintf("  etext  %08x (virt)  %08x (phys)\n", etext, etext - KERNBASE);
	cprintf("  edata  %08x (virt)  %08x (phys)\n", edata, edata - KERNBASE);
	cprintf("  end    %08x (virt)  %08x (phys)\n", end, end - KERNBASE);
	cprintf("Kernel executable memory footprint: %dKB\n",
		ROUNDUP(end - entry, 1024) / 1024);
	return 0;
}

int
mon_backtrace(int argc, char **argv, struct Trapframe *tf)
{
	// Your code here.
	//ebp = getebp()
	//while(ebp = 0){
	//cprintf(ebp,ebp[1],ebp[2]...ebp[6])
	//ebp = *ebp 这个语句会让堆栈返回
	//}
	uint32_t *ebp;
	struct Eipdebuginfo info;

    ebp = (uint32_t *)read_ebp();

    cprintf("Stack backtrace:\r\n");

    while (ebp)
    {
        cprintf("  ebp %08x  eip %08x  args %08x %08x %08x %08x %08x\r\n", 
                ebp, ebp[1], ebp[2], ebp[3], ebp[4], ebp[5], ebp[6]);
		if(	debuginfo_eip(ebp[1],&info) == 0){
			//注意，返回的Eipdebuginfo结构体的eip_fn_name字段除了函数名外还有一段尾巴，
			//比如test_backtrace:F(0,25)，需要将":F(0,25)"去掉，
			//可以使用printf("%.*s", length, string)来实现。代码如下：
			cprintf("	%s:%d: %.*s+%d\r\n",info.eip_file,info.eip_line,info.eip_fn_namelen,info.eip_fn_name,ebp[1]-info.eip_fn_addr);

		}

        ebp = (uint32_t *)*ebp;
    }

	return 0;
}



/***** Kernel monitor command interpreter *****/

#define WHITESPACE "\t\r\n "
#define MAXARGS 16

static int
runcmd(char *buf, struct Trapframe *tf)
{
	int argc;
	char *argv[MAXARGS];
	int i;

	// Parse the command buffer into whitespace-separated arguments
	argc = 0;
	argv[argc] = 0;
	while (1) {
		// gobble whitespace
		while (*buf && strchr(WHITESPACE, *buf))
			*buf++ = 0;
		if (*buf == 0)
			break;

		// save and scan past next arg
		if (argc == MAXARGS-1) {
			cprintf("Too many arguments (max %d)\n", MAXARGS);
			return 0;
		}
		argv[argc++] = buf;
		while (*buf && !strchr(WHITESPACE, *buf))
			buf++;
	}
	argv[argc] = 0;

	// Lookup and invoke the command
	if (argc == 0)
		return 0;
	for (i = 0; i < ARRAY_SIZE(commands); i++) {
		if (strcmp(argv[0], commands[i].name) == 0)
			return commands[i].func(argc, argv, tf);
	}
	cprintf("Unknown command '%s'\n", argv[0]);
	return 0;
}

void
monitor(struct Trapframe *tf)
{
	char *buf;

	cprintf("Welcome to the JOS kernel monitor!\n");
	cprintf("Type 'help' for a list of commands.\n");
	


	while (1) {
		buf = readline("K> ");
		if (buf != NULL)
			if (runcmd(buf, tf) < 0)
				break;
	}
}