/**
 * __bitmap_parse - convert an ASCII hex string into a bitmap.
 * @buf: pointer to buffer containing string.
 * @buflen: buffer size in bytes.  If string is smaller than this
 *    then it must be terminated with a \0.
 * @is_user: location of buffer, 0 indicates kernel space
 * @maskp: pointer to bitmap array that will contain result.
 * @nmaskbits: size of bitmap, in bits.
 *
 * Commas group hex digits into chunks.  Each chunk defines exactly 32
 * bits of the resultant bitmask.  No chunk may specify a value larger
 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
/**
 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
 * @list: indicates whether the bitmap must be list
 * @buf: page aligned buffer into which string is placed
 * @maskp: pointer to bitmap to convert
 * @nmaskbits: size of bitmap, in bits
 *
 * Output format is a comma-separated list of decimal numbers and
 * ranges if list is specified or hex digits grouped into comma-separated
 * sets of 8 digits/set. Returns the number of characters written to buf.
 *
 * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
 * area and that sufficient storage remains at @buf to accommodate the
 * bitmap_print_to_pagebuf() output. Returns the number of characters
 * actually printed to @buf, excluding terminating '\0'.
 */
int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
                            int nmaskbits)
{
        ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);

        return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
                      scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
}
EXPORT_SYMBOL(bitmap_print_to_pagebuf);

/*
 * Bitmap.
 *
 * (C) 2019.06.10 <buddy.zhang@aliyun.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>

/* header of bitmap */
#include <linux/bitmap.h>

static __init int bitmap_demo_init(void)
{
	unsigned long bitmap = 0x90911016;
	char buf[128];

	/* Cover bitmap to ASCII */
	bitmap_print_to_pagebuf(0, buf, &bitmap, 32);
	printk("Bitmap: %#lx to ASCII: %s", bitmap, buf);

	return 0;
}
device_initcall(bitmap_demo_init);

diff --git a/drivers/BiscuitOS/Kconfig b/drivers/BiscuitOS/Kconfig
index 4edc5a5..1a9abee 100644
--- a/drivers/BiscuitOS/Kconfig
+++ b/drivers/BiscuitOS/Kconfig
@@ -6,4 +6,14 @@ if BISCUITOS_DRV
config BISCUITOS_MISC
        bool "BiscuitOS misc driver"
+config BISCUITOS_BITMAP
+       bool "bitmap"
+
+if BISCUITOS_BITMAP
+
+config DEBUG_BISCUITOS_BITMAP
+       bool "bitmap_print_to_pagebuf"
+
+endif # BISCUITOS_BITMAP
+
endif # BISCUITOS_DRV

diff --git a/drivers/BiscuitOS/Makefile b/drivers/BiscuitOS/Makefile
index 82004c9..9909149 100644
--- a/drivers/BiscuitOS/Makefile
+++ b/drivers/BiscuitOS/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_BISCUITOS_MISC)     += BiscuitOS_drv.o
+obj-$(CONFIG_BISCUITOS_BITMAP)     += bitmap.o
--

Device Driver--->
    [*]BiscuitOS Driver--->
        [*]bitmap
            [*]bitmap_print_to_pagebuf()

usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
Bitmap: 0x90911016 to ASCII: 90911016
aaci-pl041 10004000.aaci: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 24
aaci-pl041 10004000.aaci: FIFO 512 entries
oprofile: using arm/armv7-ca9