🆕 malloc 、printf

user/libs/libc/Makefile

@@ -2,11 +2,34 @@ all: libc
 
 CFLAGS += -I .
 
+libc_sub_dirs=math
 
-libc: unistd.o fcntl.o
+
+libc: unistd.o fcntl.o malloc.o errno.o printf.o stdlib.o ctype.o
+	@list='$(libc_sub_dirs)'; for subdir in $$list; do \
+    		echo "make all in $$subdir";\
+    		cd $$subdir;\
+    		$(MAKE) all CFLAGS="$(CFLAGS) -I $(shell pwd)";\
+    		cd ..;\
+	done
 
 unistd.o: unistd.c
 	gcc $(CFLAGS) -c unistd.c -o unistd.o
 
 fcntl.o: fcntl.c
 	gcc $(CFLAGS) -c fcntl.c -o fcntl.o
+
+malloc.o: malloc.c
+	gcc $(CFLAGS) -c malloc.c -o malloc.o
+
+errno.o: errno.c
+	gcc $(CFLAGS) -c errno.c -o errno.o
+
+printf.o: printf.c
+	gcc $(CFLAGS) -c printf.c -o printf.o
+
+stdlib.o: stdlib.c
+	gcc $(CFLAGS) -c stdlib.c -o stdlib.o
+	
+ctype.o: ctype.c
+	gcc $(CFLAGS) -c ctype.c -o ctype.o

user/libs/libc/__libc__.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#pragma once
+
+#ifdef __cplusplus
+
+#    define __BEGIN_HEADER \
+        extern "C"         \
+        {
+
+#    define __END_HEADER \
+        }
+
+#else
+
+#    define __BEGIN_HEADER
+
+#    define __END_HEADER
+
+#endif

user/libs/libc/ctype.c

@@ -0,0 +1,75 @@
+#include <libc/ctype.h>
+
+
+int isprint(int c)
+{
+    if (c >= 0x20 && c <= 0x7e)
+    {
+        return 1;
+    }
+
+    return 0;
+}
+
+int islower(int c)
+{
+    if (c >= 'a' && c <= 'z')
+    {
+        return 1;
+    }
+
+    return 0;
+}
+
+int isupper(int c)
+{
+    if (c >= 'A' && c <= 'Z')
+    {
+        return 1;
+    }
+
+    return 0;
+}
+
+int isalpha(int c)
+{
+    if (islower(c) || isupper(c))
+    {
+        return 1;
+    }
+
+    return 0;
+}
+
+int isdigit(int c)
+{
+    if (c >= '0' && c <= '9')
+    {
+        return 1;
+    }
+
+    return 0;
+}
+
+int toupper(int c)
+{
+    if (c >= 'a' && c <= 'z')
+    {
+        return c - 'a' + 'A';
+    }
+    return c;
+}
+
+int tolower(int c)
+{
+    if (c >= 'A' && c <= 'Z')
+    {
+        return c - 'A' + 'a';
+    }
+    return c;
+}
+
+int isspace(int c)
+{
+    return (c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v' || c == ' ');
+}

user/libs/libc/ctype.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <libc/sys/types.h>
+
+#pragma once
+
+#include <libc/__libc__.h>
+
+
+int isalnum(int c);
+int isalpha(int c);
+int isdigit(int c);
+int islower(int c);
+int isprint(int c);
+int isgraph(int c);
+int iscntrl(int c);
+int isgraph(int c);
+int ispunct(int c);
+int isspace(int c);
+int isupper(int c);
+int isxdigit(int c);
+
+int isascii(int c);
+
+int tolower(int c);
+int toupper(int c);
+
+#define _U 01
+#define _L 02
+#define _N 04
+#define _S 010
+#define _P 020
+#define _C 040
+#define _X 0100
+#define _B 0200
+
+extern char _ctype_[256];
+

user/libs/libc/errno.c

@@ -0,0 +1,2 @@
+#include "errno.h"
+int errno = 0;

user/libs/libc/errno.h

@@ -98,4 +98,6 @@
 #define ETXTBSY 79         /* 文本文件忙 Text file busy. */
 
 #define EWOULDBLOCK 80     /* 操作将被禁止 Operation would block (may be the same value as [EAGAIN]). */
-#define EXDEV 81           /* 跨设备连接 Cross-device link. */
+#define EXDEV 81           /* 跨设备连接 Cross-device link. */
+
+extern int errno;

user/libs/libc/malloc.c

@@ -0,0 +1,392 @@
+#include <libc/stdlib.h>
+#include <libsystem/syscall.h>
+#include <libc/stddef.h>
+#include <libc/unistd.h>
+#include <libc/errno.h>
+#include <libc/stdio.h>
+
+/**
+ * @brief 显式链表的结点
+ *
+ */
+typedef struct malloc_mem_chunk_t
+{
+    uint64_t start_addr;             // 整个块所在内存区域的起始地址（包括header）
+    uint64_t length;                 // 整个块所占用的内存区域的大小
+    struct malloc_mem_chunk_t *prev; // 上一个结点的指针
+    struct malloc_mem_chunk_t *next; // 下一个结点的指针
+} malloc_mem_chunk_t;
+
+static uint64_t brk_base_addr = 0;    // 堆区域的内存基地址
+static uint64_t brk_max_addr = 0;     // 堆区域的内存最大地址
+static uint64_t brk_managed_addr = 0; // 堆区域已经被管理的地址
+
+// 空闲链表
+//  按start_addr升序排序
+static malloc_mem_chunk_t *malloc_free_list = NULL;
+// 已分配链表
+//  使用LIFO策略。基于假设：程序运行早期分配的内存会被最晚释放
+static malloc_mem_chunk_t *malloc_allocated_list = NULL;
+
+/**
+ * @brief 获取一块堆内存（不尝试扩大堆内存）
+ *
+ * @param size
+ * @return void* 内存的地址指针，获取失败时返回-ENOMEM
+ */
+static void *malloc_no_enlarge(ssize_t size);
+
+/**
+ * @brief 将块插入空闲链表
+ *
+ * @param ck 待插入的块
+ */
+static void malloc_insert_free_list(malloc_mem_chunk_t *ck);
+
+/**
+ * @brief 在链表中检索符合要求的空闲块（best fit）
+ *
+ * @param size 块的大小
+ * @return malloc_mem_chunk_t*
+ */
+static malloc_mem_chunk_t *malloc_query_free_chunk_bf(uint64_t size)
+{
+    // 在满足best fit的前提下，尽可能的使分配的内存在低地址
+    //  使得总的堆内存可以更快被释放
+
+    if (malloc_free_list == NULL)
+    {
+        printf("free list is none.\n");
+        return NULL;
+    }
+    malloc_mem_chunk_t *ptr = malloc_free_list;
+    malloc_mem_chunk_t *best = NULL;
+    printf("query size=%d", size);
+    while (ptr)
+    {
+        printf("ptr->length=%#010lx\n", ptr->length);
+        if (ptr->length == size)
+        {
+            best = ptr;
+            break;
+        }
+
+        if (ptr->length > size)
+        {
+            if (best == NULL)
+                best = ptr;
+            else if (best->length > ptr->length)
+                best = ptr;
+        }
+        ptr = ptr->next;
+    }
+
+    return best;
+}
+
+/**
+ * @brief 在链表中检索符合要求的空闲块（first fit）
+ *
+ * @param size
+ * @return malloc_mem_chunk_t*
+ */
+static malloc_mem_chunk_t *malloc_query_free_chunk_ff(uint64_t size)
+{
+    if (malloc_free_list == NULL)
+        return NULL;
+    malloc_mem_chunk_t *ptr = malloc_free_list;
+
+    while (ptr)
+    {
+        if (ptr->length >= size)
+        {
+            return ptr;
+        }
+        ptr = ptr->next;
+    }
+
+    return NULL;
+}
+
+/**
+ * @brief 扩容malloc管理的内存区域
+ *
+ * @param size 扩大的内存大小
+ */
+static int malloc_enlarge(int32_t size)
+{
+    if (brk_base_addr == 0) // 第一次调用，需要初始化
+    {
+        brk_base_addr = brk(-1);
+        printf("brk_base_addr=%#018lx\n", brk_base_addr);
+        brk_managed_addr = brk_base_addr;
+        brk_max_addr = brk(-2);
+    }
+
+    int64_t tmp = brk_managed_addr + size - brk_max_addr;
+    if (tmp > 0) // 现有堆空间不足
+    {
+        if (sbrk(tmp) != (-1))
+            brk_max_addr = brk((-1));
+        else
+        {
+            put_string("malloc_enlarge(): no_mem", COLOR_YELLOW, COLOR_BLACK);
+            return -ENOMEM;
+        }
+    }
+
+    // 扩展管理的堆空间
+    // 在新分配的内存的底部放置header
+    malloc_mem_chunk_t *new_ck = (malloc_mem_chunk_t *)brk_managed_addr;
+    new_ck->start_addr = (uint64_t)new_ck;
+    new_ck->length = brk_max_addr - brk_managed_addr;
+    printf("new_ck->start_addr=%#018lx\tbrk_max_addr=%#018lx\tbrk_managed_addr=%#018lx\n", new_ck->start_addr, brk_max_addr, brk_managed_addr);
+    new_ck->prev = new_ck->next = NULL;
+    brk_managed_addr = brk_max_addr;
+
+    malloc_insert_free_list(new_ck);
+
+    return 0;
+}
+
+/**
+ * @brief 合并空闲块
+ *
+ */
+static void malloc_merge_free_chunk()
+{
+    if (malloc_free_list == NULL)
+        return;
+    malloc_mem_chunk_t *ptr = malloc_free_list->next;
+    while (ptr)
+    {
+        // 内存块连续
+        if (ptr->prev->start_addr + ptr->prev->length == ptr->start_addr)
+        {
+            // 将ptr与前面的空闲块合并
+            ptr->prev->length += ptr->length;
+            ptr->prev->next = ptr->next;
+            // 由于内存组成结构的原因，不需要free掉header
+            ptr = ptr->prev;
+        }
+        ptr = ptr->next;
+    }
+}
+
+/**
+ * @brief 将块插入空闲链表
+ *
+ * @param ck 待插入的块
+ */
+static void malloc_insert_free_list(malloc_mem_chunk_t *ck)
+{
+    if (malloc_free_list == NULL) // 空闲链表为空
+    {
+        malloc_free_list = ck;
+        ck->prev = ck->next = NULL;
+        return;
+    }
+    else
+    {
+        uint64_t ck_end = ck->start_addr + ck->length;
+        malloc_mem_chunk_t *ptr = malloc_free_list;
+        while (ptr)
+        {
+            if (ptr->start_addr < ck->start_addr)
+            {
+                if (ptr->next == NULL) // 当前是最后一个项
+                {
+                    ptr->next = ck;
+                    ck->next = NULL;
+                    ck->prev = ptr;
+                    break;
+                }
+                else if (ptr->next->start_addr > ck->start_addr)
+                {
+                    ck->prev = ptr;
+                    ck->next = ptr->next;
+                    ck->prev->next = ck;
+                    ck->next->prev = ck;
+                    break;
+                }
+            }
+            else // 在ptr之前插入
+            {
+
+                if (ptr->prev == NULL) // 是第一个项
+                {
+                    malloc_free_list = ck;
+                    ck->prev = NULL;
+                    ck->next = ptr;
+                    ptr->prev = ck;
+                    break;
+                }
+                else
+                {
+                    ck->prev = ptr->prev;
+                    ck->next = ptr;
+                    ck->prev->next = ck;
+                    ptr->prev = ck;
+                    break;
+                }
+            }
+            ptr = ptr->next;
+        }
+    }
+}
+
+/**
+ * @brief 获取一块堆内存（不尝试扩大堆内存）
+ *
+ * @param size
+ * @return void* 内存的地址指针，获取失败时返回-ENOMEM
+ */
+static void *malloc_no_enlarge(ssize_t size)
+{
+    // 加上header的大小
+    size += sizeof(malloc_mem_chunk_t);
+
+    // 采用best fit
+    malloc_mem_chunk_t *ck = malloc_query_free_chunk_bf(size);
+
+    if (ck == NULL) // 没有空闲块
+    {
+        // 尝试合并空闲块
+
+        malloc_merge_free_chunk();
+        ck = malloc_query_free_chunk_bf(size);
+
+        // 找到了合适的块
+        if (ck)
+            goto found;
+        else
+            return -ENOMEM; // 内存不足
+    }
+found:;
+    // 分配空闲块
+    // 从空闲链表取出
+    if (ck->prev == NULL) // 当前是链表的第一个块
+    {
+        malloc_free_list = ck->next;
+    }
+    else
+        ck->prev->next = ck->next;
+
+    if (ck->next != NULL) // 当前不是最后一个块
+        ck->next->prev = ck->prev;
+
+    // 当前块剩余的空间还能容纳多一个结点的空间，则分裂当前块
+    if (ck->length - size > sizeof(malloc_mem_chunk_t))
+    {
+        malloc_mem_chunk_t *new_ck = ((uint64_t)ck) + ck->length;
+        new_ck->length = ck->length - size;
+        new_ck->start_addr = (uint64_t)new_ck;
+        new_ck->prev = new_ck->next = NULL;
+
+        ck->length = size;
+        malloc_insert_free_list(new_ck);
+    }
+
+    // 插入到已分配链表
+    // 直接插入到链表头，符合LIFO
+    ck->prev = NULL;
+    if (malloc_allocated_list) // 已分配链表不为空
+    {
+        malloc_allocated_list->prev = ck;
+        ck->next = malloc_allocated_list;
+        malloc_allocated_list = ck;
+    }
+    else // 已分配链表为空
+    {
+        malloc_allocated_list = ck;
+        ck->next = NULL;
+    }
+    return (void *)(ck->start_addr + sizeof(malloc_mem_chunk_t));
+}
+/**
+ * @brief 获取一块堆内存
+ *
+ * @param size 内存大小
+ * @return void* 内存空间的指针
+ */
+void *malloc(ssize_t size)
+{
+    // 加上header的大小
+    size += sizeof(malloc_mem_chunk_t);
+
+    // 采用best fit
+    malloc_mem_chunk_t *ck = malloc_query_free_chunk_bf(size);
+
+    if (ck == NULL) // 没有空闲块
+    {
+
+        // 尝试合并空闲块
+        printf("merge\n");
+        malloc_merge_free_chunk();
+        ck = malloc_query_free_chunk_bf(size);
+
+        // 找到了合适的块
+        if (ck)
+            goto found;
+        // 找不到合适的块，扩容堆区域
+        printf("enlarge\n");
+        if (malloc_enlarge(size) == -ENOMEM)
+            return -ENOMEM; // 内存不足
+        // 扩容后再次尝试获取
+        printf("query\n");
+        ck = malloc_query_free_chunk_bf(size);
+    }
+found:;
+    if (ck == NULL)
+        return -ENOMEM;
+    // 分配空闲块
+    // 从空闲链表取出
+    if (ck->prev == NULL) // 当前是链表的第一个块
+    {
+        malloc_free_list = ck->next;
+    }
+    else
+        ck->prev->next = ck->next;
+
+    if (ck->next != NULL) // 当前不是最后一个块
+        ck->next->prev = ck->prev;
+
+    // 当前块剩余的空间还能容纳多一个结点的空间，则分裂当前块
+    if (ck->length - size > sizeof(malloc_mem_chunk_t))
+    {
+        malloc_mem_chunk_t *new_ck = ((uint64_t)ck) + ck->length;
+        new_ck->length = ck->length - size;
+        new_ck->start_addr = (uint64_t)new_ck;
+        new_ck->prev = new_ck->next = NULL;
+
+        ck->length = size;
+        malloc_insert_free_list(new_ck);
+    }
+
+    // 插入到已分配链表
+    // 直接插入到链表头，符合LIFO
+    ck->prev = NULL;
+    if (malloc_allocated_list) // 已分配链表不为空
+    {
+        malloc_allocated_list->prev = ck;
+        ck->next = malloc_allocated_list;
+        malloc_allocated_list = ck;
+    }
+    else // 已分配链表为空
+    {
+        malloc_allocated_list = ck;
+        ck->next = NULL;
+    }
+    printf("ck=%lld\n", (uint64_t)ck);
+    printf("ck->start_addr=%lld\n", ck->start_addr);
+    return (void *)(ck->start_addr + sizeof(malloc_mem_chunk_t));
+}
+
+/**
+ * @brief 释放一块堆内存
+ *
+ * @param ptr 堆内存的指针
+ */
+void free(void *ptr)
+{
+}

user/libs/libc/math.h

@@ -0,0 +1,10 @@
+#pragma once
+
+
+double fabs(double x);
+float fabsf(float x);
+long double fabsl(long double x);
+
+double round(double x);
+float roundf(float x);
+long double roundl(long double x);

user/libs/libc/math/Makefile

@@ -0,0 +1,11 @@
+
+all: fabs.o round.o
+
+CFLAGS += -I .
+
+
+fabs.o: fabs.c
+	gcc $(CFLAGS) -c fabs.c -o fabs.o
+
+round.o: round.c
+	gcc $(CFLAGS) -c round.c -o round.o

user/libs/libc/math/fabs.c

@@ -0,0 +1,29 @@
+#include <libc/math.h>
+#include <libc/sys/types.h>
+#include "libm.h"
+double fabs(double x)
+{
+    union
+    {
+        double f;
+        uint64_t i;
+    } u = {x};
+    u.i &= -1ULL / 2;
+    return u.f;
+}
+
+
+#if __LDBL_MANT_DIG__ == 53 &&  __LDBL_MAX_EXP__ == 1024
+long double fabsl(long double x)
+{
+	return fabs(x);
+}
+#elif (__LDBL_MANT_DIG__ == 64 || __LDBL_MANT_DIG__ == 113) && __LDBL_MAX_EXP__ == 16384
+long double fabsl(long double x)
+{
+	union ldshape u = {x};
+
+	u.i.se &= 0x7fff;
+	return u.f;
+}
+#endif

user/libs/libc/math/libm.h

@@ -0,0 +1,75 @@
+#pragma once
+#include <libc/sys/types.h>
+
+// ===== 描述long double 的数据比特结构
+#if __LDBL_MANT_DIG__ == 53 && __LDBL_MAX_EXP__ == 1024
+#elif __LDBL_MANT_DIG__ == 64 && __LDBL_MAX_EXP__ == 16384 && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+union ldshape
+{
+    long double f;
+    struct
+    {
+        uint64_t m;
+        uint16_t se;
+    } i;
+};
+#elif __LDBL_MANT_DIG__ == 113 && __LDBL_MAX_EXP__ == 16384 && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+union ldshape
+{
+    long double f;
+    struct
+    {
+        uint64_t lo;
+        uint32_t mid;
+        uint16_t top;
+        uint16_t se;
+    } i;
+    struct
+    {
+        uint64_t lo;
+        uint64_t hi;
+    } i2;
+};
+#elif __LDBL_MANT_DIG__ == 113 && __LDBL_MAX_EXP__ == 16384 && __BYTE_ORDER__ == __BIG_ENDIAN
+union ldshape
+{
+    long double f;
+    struct
+    {
+        uint16_t se;
+        uint16_t top;
+        uint32_t mid;
+        uint64_t lo;
+    } i;
+    struct
+    {
+        uint64_t hi;
+        uint64_t lo;
+    } i2;
+};
+#else
+#error Unsupported long double representation
+#endif
+
+#define FORCE_EVAL(x)                         \
+    do                                        \
+    {                                         \
+        if (sizeof(x) == sizeof(float))       \
+        {                                     \
+            volatile float __x;               \
+            __x = (x);                        \
+            (void)__x;                        \
+        }                                     \
+        else if (sizeof(x) == sizeof(double)) \
+        {                                     \
+            volatile double __x;              \
+            __x = (x);                        \
+            (void)__x;                        \
+        }                                     \
+        else                                  \
+        {                                     \
+            volatile long double __x;         \
+            __x = (x);                        \
+            (void)__x;                        \
+        }                                     \
+    } while (0)

user/libs/libc/math/round.c

@@ -0,0 +1,43 @@
+
+
+#include "libm.h"
+
+#if __FLT_EVAL_METHOD__ == 0 || __FLT_EVAL_METHOD__ == 1
+#define EPS __DBL_EPSILON__
+#elif __FLT_EVAL_METHOD__ == 2
+#define EPS __LDBL_EPSILON__
+#endif
+static const double toint = 1 / EPS;
+
+double round(double x)
+{
+    union
+    {
+        double f;
+        uint64_t i;
+    } u = {x};
+    
+    int e = u.i >> 52 & 0x7ff;
+    double y;
+
+    if (e >= 0x3ff + 52)
+        return x;
+    if (u.i >> 63)
+        x = -x;
+    if (e < 0x3ff - 1)
+    {
+        /* raise inexact if x!=0 */
+        FORCE_EVAL(x + toint);
+        return 0 * u.f;
+    }
+    y = x + toint - toint - x;
+    if (y > 0.5)
+        y = y + x - 1;
+    else if (y <= -0.5)
+        y = y + x + 1;
+    else
+        y = y + x;
+    if (u.i >> 63)
+        y = -y;
+    return y;
+}

user/libs/libc/printf.c

@@ -0,0 +1,536 @@
+#include "printf.h"
+
+#include <libc/stdio.h>
+#include <libsystem/syscall.h>
+#include <libc/string.h>
+#include <libc/math.h>
+#include <libc/stdlib.h>
+
+static char *write_num(char *str, uint64_t num, int base, int field_width, int precision, int flags);
+static char *write_float_point_num(char *str, double num, int field_width, int precision, int flags);
+
+/**
+ * @brief 往屏幕上输出字符串
+ *
+ * @param str 字符串指针
+ * @param front_color 前景色
+ * @param bg_color 背景色
+ * @return int64_t
+ */
+int64_t put_string(char *str, uint64_t front_color, uint64_t bg_color)
+{
+    return syscall_invoke(SYS_PUT_STRING, (uint64_t)str, front_color, bg_color, 0, 0, 0, 0, 0);
+}
+
+int printf(const char *fmt, ...)
+{
+    char buf[4096];
+    int count = 0;
+    va_list args;
+    va_start(args, fmt);
+
+    count = vsprintf(buf, fmt, args);
+    va_end(args);
+    put_string(buf, COLOR_WHITE, COLOR_BLACK);
+    return count;
+}
+
+int sprintf(char *buf, const char *fmt, ...)
+{
+    int count = 0;
+    va_list args;
+
+    va_start(args, fmt);
+    count = vsprintf(buf, fmt, args);
+    va_end(args);
+
+    return count;
+}
+
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+    /**
+     * 将字符串按照fmt和args中的内容进行格式化，然后保存到buf中
+     * @param buf 结果缓冲区
+     * @param fmt 格式化字符串
+     * @param args 内容
+     * @return 最终字符串的长度
+     */
+
+    char *str, *s;
+
+    str = buf;
+
+    int flags;       // 用来存储格式信息的bitmap
+    int field_width; //区域宽度
+    int precision;   //精度
+    int qualifier;   //数据显示的类型
+    int len;
+
+    //开始解析字符串
+    for (; *fmt; ++fmt)
+    {
+        //内容不涉及到格式化，直接输出
+        if (*fmt != '%')
+        {
+            *str = *fmt;
+            ++str;
+            continue;
+        }
+
+        //开始格式化字符串
+
+        //清空标志位和field宽度
+        field_width = flags = 0;
+
+        bool flag_tmp = true;
+        bool flag_break = false;
+
+        ++fmt;
+        while (flag_tmp)
+        {
+            switch (*fmt)
+            {
+            case '\0':
+                //结束解析
+                flag_break = true;
+                flag_tmp = false;
+                break;
+
+            case '-':
+                // 左对齐
+                flags |= LEFT;
+                ++fmt;
+                break;
+            case '+':
+                //在正数前面显示加号
+                flags |= PLUS;
+                ++fmt;
+                break;
+            case ' ':
+                flags |= SPACE;
+                ++fmt;
+                break;
+            case '#':
+                //在八进制数前面显示 '0o'，在十六进制数前面显示 '0x' 或 '0X'
+                flags |= SPECIAL;
+                ++fmt;
+                break;
+            case '0':
+                //显示的数字之前填充‘0’来取代空格
+                flags |= PAD_ZERO;
+                ++fmt;
+                break;
+            default:
+                flag_tmp = false;
+                break;
+            }
+        }
+        if (flag_break)
+            break;
+
+        //获取区域宽度
+        field_width = -1;
+        if (*fmt == '*')
+        {
+            field_width = va_arg(args, int);
+            ++fmt;
+        }
+        else if (is_digit(*fmt))
+        {
+            field_width = atoi(&fmt);
+            if (field_width < 0)
+            {
+                field_width = -field_width;
+                flags |= LEFT;
+            }
+        }
+
+        //获取小数精度
+        precision = -1;
+        if (*fmt == '.')
+        {
+            ++fmt;
+            if (*fmt == '*')
+            {
+                precision = va_arg(args, int);
+                ++fmt;
+            }
+            else if is_digit (*fmt)
+            {
+                precision = atoi(&fmt);
+            }
+        }
+
+        //获取要显示的数据的类型
+        if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt == 'Z')
+        {
+            qualifier = *fmt;
+            ++fmt;
+        }
+        //为了支持lld
+        if (qualifier == 'l' && *fmt == 'l', *(fmt + 1) == 'd')
+            ++fmt;
+
+        //转化成字符串
+        long long *ip;
+        switch (*fmt)
+        {
+        //输出 %
+        case '%':
+            *str++ = '%';
+
+            break;
+        // 显示一个字符
+        case 'c':
+            //靠右对齐
+            if (!(flags & LEFT))
+            {
+                while (--field_width > 0)
+                {
+                    *str = ' ';
+                    ++str;
+                }
+            }
+
+            *str++ = (unsigned char)va_arg(args, int);
+
+            while (--field_width > 0)
+            {
+                *str = ' ';
+                ++str;
+            }
+
+            break;
+
+        //显示一个字符串
+        case 's':
+            s = va_arg(args, char *);
+            if (!s)
+                s = '\0';
+            len = strlen(s);
+            if (precision < 0)
+            {
+                //未指定精度
+                precision = len;
+            }
+
+            else if (len > precision)
+            {
+                len = precision;
+            }
+
+            //靠右对齐
+            if (!(flags & LEFT))
+                while (len < field_width--)
+                {
+                    *str = ' ';
+                    ++str;
+                }
+
+            for (int i = 0; i < len; i++)
+            {
+                *str = *s;
+                ++s;
+                ++str;
+            }
+
+            while (len < field_width--)
+            {
+                *str = ' ';
+                ++str;
+            }
+
+            break;
+        //以八进制显示字符串
+        case 'o':
+            flags |= SMALL;
+        case 'O':
+            flags |= SPECIAL;
+            if (qualifier == 'l')
+                str = write_num(str, va_arg(args, long long), 8, field_width, precision, flags);
+            else
+                str = write_num(str, va_arg(args, int), 8, field_width, precision, flags);
+            break;
+
+        //打印指针指向的地址
+        case 'p':
+            if (field_width == 0)
+            {
+                field_width = 2 * sizeof(void *);
+                flags |= PAD_ZERO;
+            }
+
+            str = write_num(str, (unsigned long)va_arg(args, void *), 16, field_width, precision, flags);
+
+            break;
+
+        //打印十六进制
+        case 'x':
+            flags |= SMALL;
+        case 'X':
+            // flags |= SPECIAL;
+            if (qualifier == 'l')
+                str = write_num(str, va_arg(args, int64_t), 16, field_width, precision, flags);
+            else
+                str = write_num(str, va_arg(args, int), 16, field_width, precision, flags);
+            break;
+
+        //打印十进制有符号整数
+        case 'i':
+        case 'd':
+
+            flags |= SIGN;
+            if (qualifier == 'l')
+                str = write_num(str, va_arg(args, long long), 10, field_width, precision, flags);
+            else
+                str = write_num(str, va_arg(args, int), 10, field_width, precision, flags);
+            break;
+
+        //打印十进制无符号整数
+        case 'u':
+            if (qualifier == 'l')
+                str = write_num(str, va_arg(args, unsigned long long), 10, field_width, precision, flags);
+            else
+                str = write_num(str, va_arg(args, unsigned int), 10, field_width, precision, flags);
+            break;
+
+        //输出有效字符数量到*ip对应的变量
+        case 'n':
+
+            if (qualifier == 'l')
+                ip = va_arg(args, long long *);
+            else
+                ip = (int64_t *)va_arg(args, int *);
+
+            *ip = str - buf;
+            break;
+        case 'f':
+            // 默认精度为3
+            // printk("1111\n");
+            // va_arg(args, double);
+            // printk("222\n");
+
+            if (precision < 0)
+                precision = 3;
+
+            str = write_float_point_num(str, va_arg(args, double), field_width, precision, flags);
+
+            break;
+
+        //对于不识别的控制符，直接输出
+        default:
+            *str++ = '%';
+            if (*fmt)
+                *str++ = *fmt;
+            else
+                --fmt;
+            break;
+        }
+    }
+    *str = '\0';
+
+    //返回缓冲区已有字符串的长度。
+    return str - buf;
+}
+
+static char *write_num(char *str, uint64_t num, int base, int field_width, int precision, int flags)
+{
+    /**
+     * @brief 将数字按照指定的要求转换成对应的字符串
+     *
+     * @param str 要返回的字符串
+     * @param num 要打印的数值
+     * @param base 基数
+     * @param field_width 区域宽度
+     * @param precision 精度
+     * @param flags 标志位
+     */
+
+    // 首先判断是否支持该进制
+    if (base < 2 || base > 36)
+        return 0;
+    char pad, sign, tmp_num[100];
+
+    const char *digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    // 显示小写字母
+    if (flags & SMALL)
+        digits = "0123456789abcdefghijklmnopqrstuvwxyz";
+
+    if (flags & LEFT)
+        flags &= ~PAD_ZERO;
+    // 设置填充元素
+    pad = (flags & PAD_ZERO) ? '0' : ' ';
+
+    sign = 0;
+
+    if (flags & SIGN)
+    {
+        int64_t signed_num = (int64_t)num;
+        if (signed_num < 0)
+        {
+            sign = '-';
+            num = -signed_num;
+        }
+        else
+            num = signed_num;
+    }
+    else
+    {
+        // 设置符号
+        sign = (flags & PLUS) ? '+' : ((flags & SPACE) ? ' ' : 0);
+    }
+
+    // sign占用了一个宽度
+    if (sign)
+        --field_width;
+
+    if (flags & SPECIAL)
+        if (base == 16) // 0x占用2个位置
+            field_width -= 2;
+        else if (base == 8) // O占用一个位置
+            --field_width;
+
+    int js_num = 0; // 临时数字字符串tmp_num的长度
+
+    if (num == 0)
+        tmp_num[js_num++] = '0';
+    else
+    {
+        num = llabs(num);
+        //进制转换
+        while (num > 0)
+        {
+            tmp_num[js_num++] = digits[num % base]; // 注意这里，输出的数字，是小端对齐的。低位存低位
+            num /= base;
+        }
+    }
+
+    if (js_num > precision)
+        precision = js_num;
+
+    field_width -= precision;
+
+    // 靠右对齐
+    if (!(flags & (LEFT + PAD_ZERO)))
+        while (field_width-- > 0)
+            *str++ = ' ';
+
+    if (sign)
+        *str++ = sign;
+    if (flags & SPECIAL)
+        if (base == 16)
+        {
+            *str++ = '0';
+            *str++ = digits[33];
+        }
+        else if (base == 8)
+            *str++ = digits[24]; //注意这里是英文字母O或者o
+    if (!(flags & LEFT))
+        while (field_width-- > 0)
+            *str++ = pad;
+    while (js_num < precision)
+    {
+        --precision;
+        *str++ = '0';
+    }
+
+    while (js_num-- > 0)
+        *str++ = tmp_num[js_num];
+
+    while (field_width-- > 0)
+        *str++ = ' ';
+
+    return str;
+}
+
+static char *write_float_point_num(char *str, double num, int field_width, int precision, int flags)
+{
+    /**
+     * @brief 将浮点数按照指定的要求转换成对应的字符串
+     *
+     * @param str 要返回的字符串
+     * @param num 要打印的数值
+     * @param field_width 区域宽度
+     * @param precision 精度
+     * @param flags 标志位
+     */
+
+    char pad, sign, tmp_num_z[100], tmp_num_d[350];
+
+    const char *digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    // 显示小写字母
+    if (flags & SMALL)
+        digits = "0123456789abcdefghijklmnopqrstuvwxyz";
+
+    // 设置填充元素
+    pad = (flags & PAD_ZERO) ? '0' : ' ';
+    sign = 0;
+    if (flags & SIGN && num < 0)
+    {
+        sign = '-';
+        num = -num;
+    }
+    else
+    {
+        // 设置符号
+        sign = (flags & PLUS) ? '+' : ((flags & SPACE) ? ' ' : 0);
+    }
+
+    // sign占用了一个宽度
+    if (sign)
+        --field_width;
+
+    int js_num_z = 0, js_num_d = 0;                                      // 临时数字字符串tmp_num_z tmp_num_d的长度
+    uint64_t num_z = (uint64_t)(num);                                    // 获取整数部分
+    uint64_t num_decimal = (uint64_t)(round((num - num_z) * precision)); // 获取小数部分
+
+    if (num == 0)
+        tmp_num_z[js_num_z++] = '0';
+    else
+    {
+        //存储整数部分
+        while (num_z > 0)
+        {
+            tmp_num_z[js_num_z++] = digits[num_z % 10]; // 注意这里，输出的数字，是小端对齐的。低位存低位
+            num_z /= 10;
+        }
+    }
+
+    while (num_decimal > 0)
+    {
+        tmp_num_d[js_num_d++] = digits[num_decimal % 10];
+        num_decimal /= 10;
+    }
+
+    field_width -= (precision + 1 + js_num_z);
+
+    // 靠右对齐
+    if (!(flags & LEFT))
+        while (field_width-- > 0)
+            *str++ = pad;
+
+    if (sign)
+        *str++ = sign;
+
+    // 输出整数部分
+    while (js_num_z-- > 0)
+        *str++ = tmp_num_z[js_num_z];
+
+    *str++ = '.';
+
+    // 输出小数部分
+    while (js_num_d-- > 0)
+        *str++ = tmp_num_d[js_num_d];
+
+    while (js_num_d < precision)
+    {
+        --precision;
+        *str++ = '0';
+    }
+
+    while (field_width-- > 0)
+        *str++ = ' ';
+
+    return str;
+}

user/libs/libc/printf.h

@@ -0,0 +1,13 @@
+#pragma once
+
+
+#define PAD_ZERO 1 // 0填充
+#define LEFT 2     // 靠左对齐
+#define RIGHT 4    // 靠右对齐
+#define PLUS 8     // 在正数前面显示加号
+#define SPACE 16
+#define SPECIAL 32 // 在八进制数前面显示 '0o'，在十六进制数前面显示 '0x' 或 '0X'
+#define SMALL 64   // 十进制以上数字显示小写字母
+#define SIGN 128   // 显示符号位
+
+#define is_digit(c) ((c) >= '0' && (c) <= '9') // 用来判断是否是数字的宏

user/libs/libc/stddef.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <libc/sys/types.h>
+
+#ifdef __cplusplus
+   #define NULL 0
+#else
+   #define NULL ((void *)0)
+#endif
+
+
+typedef __PTRDIFF_TYPE__ ptrdiff_t; // Signed integer type of the result of subtracting two pointers.
+

user/libs/libc/stdio.h

@@ -1,7 +1,35 @@
 #pragma once
 
-#define	SEEK_SET	0	/* Seek relative to start-of-file */
-#define	SEEK_CUR	1	/* Seek relative to current position */
-#define	SEEK_END	2	/* Seek relative to end-of-file */
+#include <libc/sys/types.h>
+#include <stdarg.h>
 
-#define SEEK_MAX	3
+// 字体颜色的宏定义
+#define COLOR_WHITE 0x00ffffff  //白
+#define COLOR_BLACK 0x00000000  //黑
+#define COLOR_RED 0x00ff0000    //红
+#define COLOR_ORANGE 0x00ff8000 //橙
+#define COLOR_YELLOW 0x00ffff00 //黄
+#define COLOR_GREEN 0x0000ff00  //绿
+#define COLOR_BLUE 0x000000ff   //蓝
+#define COLOR_INDIGO 0x0000ffff //靛
+#define COLOR_PURPLE 0x008000ff //紫
+
+#define SEEK_SET 0 /* Seek relative to start-of-file */
+#define SEEK_CUR 1 /* Seek relative to current position */
+#define SEEK_END 2 /* Seek relative to end-of-file */
+
+#define SEEK_MAX 3
+
+/**
+ * @brief 往屏幕上输出字符串
+ *
+ * @param str 字符串指针
+ * @param front_color 前景色
+ * @param bg_color 背景色
+ * @return int64_t
+ */
+int64_t put_string(char *str, uint64_t front_color, uint64_t bg_color);
+
+int printf(const char *fmt, ...);
+int sprintf(char *buf, const char *fmt, ...);
+int vsprintf(char *buf, const char *fmt, va_list args);

user/libs/libc/stdlib.c

@@ -0,0 +1,45 @@
+#include <libc/unistd.h>
+#include <libc/stdlib.h>
+
+int abs(int i)
+{
+    return i < 0 ? -i : i;
+}
+
+long labs(long i)
+{
+    return i < 0 ? -i : i;
+}
+
+long long llabs(long long i)
+{
+    return i < 0 ? -i : i;
+}
+
+int atoi(const char *str)
+{
+    int n = 0, neg = 0;
+
+    while (isspace(*str))
+    {
+        str++;
+    }
+
+    switch (*str)
+    {
+    case '-':
+        neg = 1;
+        break;
+    case '+':
+        str++;
+        break;
+    }
+
+    /* Compute n as a negative number to avoid overflow on INT_MIN */
+    while (isdigit(*str))
+    {
+        n = 10 * n - (*str++ - '0');
+    }
+
+    return neg ? n : -n;
+}

user/libs/libc/stdlib.h

@@ -0,0 +1,35 @@
+#pragma once
+#include <libc/sys/types.h>
+
+/**
+ * @brief 获取一块堆内存
+ * 
+ * @param size 内存大小
+ * @return void* 内存空间的指针
+ */
+void *malloc(ssize_t size);
+
+/**
+ * @brief 释放一块堆内存
+ * 
+ * @param ptr 堆内存的指针
+ */
+void free(void* ptr);
+
+/**
+ * @brief 返回int的绝对值
+ * 
+ * @param i 
+ * @return int 
+ */
+int abs(int i);
+long labs(long i);
+long long llabs(long long i);
+
+/**
+ * @brief 字符串转int
+ * 
+ * @param str 
+ * @return int 
+ */
+int atoi(const char * str);

user/libs/libc/string.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <libc/sys/types.h>
+
+void *memset(void *dst, unsigned char C, uint64_t size)
+{
+
+    int d0, d1;
+    unsigned long tmp = C * 0x0101010101010101UL;
+    __asm__ __volatile__("cld	\n\t"
+                         "rep	\n\t"
+                         "stosq	\n\t"
+                         "testb	$4, %b3	\n\t"
+                         "je	1f	\n\t"
+                         "stosl	\n\t"
+                         "1:\ttestb	$2, %b3	\n\t"
+                         "je	2f\n\t"
+                         "stosw	\n\t"
+                         "2:\ttestb	$1, %b3	\n\t"
+                         "je	3f	\n\t"
+                         "stosb	\n\t"
+                         "3:	\n\t"
+                         : "=&c"(d0), "=&D"(d1)
+                         : "a"(tmp), "q"(size), "0"(size / 8), "1"(dst)
+                         : "memory");
+    return dst;
+}
+
+size_t strlen(const char *s)
+{
+    register size_t __res = 0;
+    while (s[__res] != '\0')
+    {
+        ++__res;
+    }
+    return __res;
+}

user/libs/libc/sys/types.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <stdbool.h>
 
 typedef unsigned char u_char;
 typedef unsigned short u_short;

user/libs/libc/unistd.c

@@ -1,18 +1,8 @@
 #include <libc/unistd.h>
 #include <libsystem/syscall.h>
+#include <libc/errno.h>
+#include <libc/stdio.h>
 
-/**
- * @brief 往屏幕上输出字符串
- *
- * @param str 字符串指针
- * @param front_color 前景色
- * @param bg_color 背景色
- * @return int64_t
- */
-int64_t put_string(char *str, uint64_t front_color, uint64_t bg_color)
-{
-    return syscall_invoke(SYS_PUT_STRING, (uint64_t)str, front_color, bg_color, 0, 0, 0, 0, 0);
-}
 /**
  * @brief 关闭文件接口
  *
@@ -81,4 +71,38 @@ pid_t fork(void)
 pid_t vfork(void)
 {
     return (pid_t)syscall_invoke(SYS_VFORK, 0, 0, 0, 0, 0, 0, 0, 0);
+}
+
+/**
+ * @brief 将堆内存调整为end_brk
+ *
+ * @param end_brk 新的堆区域的结束地址
+ * end_brk=-1  ===> 返回堆区域的起始地址
+ * end_brk=-2  ===> 返回堆区域的结束地址
+ * @return uint64_t 错误码
+ *
+ */
+uint64_t brk(uint64_t end_brk)
+{
+    uint64_t x = (uint64_t)syscall_invoke(SYS_BRK, (uint64_t)end_brk, 0, 0, 0, 0, 0, 0, 0);
+    printf("brk():  end_brk=%#018lx x=%#018lx", (uint64_t)end_brk, x);
+    return x;
+}
+
+/**
+ * @brief 将堆内存空间加上offset（注意，该系统调用只应在普通进程中调用，而不能是内核线程）
+ *
+ * @param increment offset偏移量
+ * @return uint64_t the previous program break
+ */
+void *sbrk(int64_t increment)
+{
+    void *retval = (void *)syscall_invoke(SYS_SBRK, (uint64_t)increment, 0, 0, 0, 0, 0, 0, 0);
+    if (retval == (void *)-ENOMEM)
+        return (void *)(-1);
+    else
+    {
+        errno = 0;
+        return (void *)retval;
+    }
 }

user/libs/libc/unistd.h

@@ -2,27 +2,9 @@
 #include <stdint.h>
 #include <libc/sys/types.h>
 
-// 字体颜色的宏定义
-#define COLOR_WHITE 0x00ffffff  //白
-#define COLOR_BLACK 0x00000000  //黑
-#define COLOR_RED 0x00ff0000    //红
-#define COLOR_ORANGE 0x00ff8000 //橙
-#define COLOR_YELLOW 0x00ffff00 //黄
-#define COLOR_GREEN 0x0000ff00  //绿
-#define COLOR_BLUE 0x000000ff   //蓝
-#define COLOR_INDIGO 0x0000ffff //靛
-#define COLOR_PURPLE 0x008000ff //紫
 
 
-/**
- * @brief 往屏幕上输出字符串
- * 
- * @param str 字符串指针
- * @param front_color 前景色
- * @param bg_color 背景色
- * @return int64_t 
- */
-int64_t put_string(char* str, uint64_t front_color, uint64_t bg_color);
+
 
 
 /**
@@ -77,3 +59,21 @@ pid_t fork(void);
  */
 pid_t vfork(void);
 
+/**
+ * @brief 将堆内存调整为end_brk
+ *
+ * @param end_brk 新的堆区域的结束地址
+ * end_brk=0  ===> 返回堆区域的起始地址
+ * end_brk=-1  ===> 返回堆区域的结束地址
+ * @return uint64_t 错误码
+ * 
+ */
+uint64_t brk(uint64_t end_brk);
+
+/**
+ * @brief 将堆内存空间加上offset（注意，该系统调用只应在普通进程中调用，而不能是内核线程）
+ * 
+ * @param increment offset偏移量
+ * @return uint64_t the previous program break
+ */
+void * sbrk(int64_t increment);