I am trying to compile the source code for chapter 21 and am getting many errors. Hello.c is the only one that is compiling (probably because of the simplicity). For example when I 'make' schar I get the following out put:

gcc -D__KERNEL__ -I/usr/src/linux/include -DMODULE -Wall -O2 -c -o schar.o schar.c
In file included from /usr/src/linux/include/linux/string.h:25,
                 from /usr/src/linux/include/linux/fs.h:23,
                 from /usr/src/linux/include/linux/capability.h:17,
                 from /usr/src/linux/include/linux/binfmts.h:5,
                 from /usr/src/linux/include/linux/sched.h:9,
                 from schar.c:17:
/usr/src/linux/include/asm/string.h: In function `__constant_memcpy3d':
/usr/src/linux/include/asm/string.h:300: warning: implicit declaration of function `_mmx_memcpy_Rsmp_15670e2d'
/usr/src/linux/include/asm/string.h:300: warning: return makes pointer from integer without a cast
/usr/src/linux/include/asm/string.h: In function `__memcpy3d':
/usr/src/linux/include/asm/string.h:307: warning: return makes pointer from integer without a cast
In file included from /usr/src/linux/include/linux/highmem.h:5,
                 from /usr/src/linux/include/linux/vmalloc.h:8,
                 from /usr/src/linux/include/asm/io.h:47,
                 from schar.c:26:
/usr/src/linux/include/asm/pgalloc.h: In function `get_pgd_fast':
/usr/src/linux/include/asm/pgalloc.h:78: `cpu_data_Rsmp_d3b73c3c' undeclared (first use in this function)
/usr/src/linux/include/asm/pgalloc.h:78: (Each undeclared identifier is reported only once
/usr/src/linux/include/asm/pgalloc.h:78: for each function it appears in.)
/usr/src/linux/include/asm/pgalloc.h: In function `free_pgd_fast':
/usr/src/linux/include/asm/pgalloc.h:89: `cpu_data_Rsmp_d3b73c3c' undeclared (first use in this function)
/usr/src/linux/include/asm/pgalloc.h: In function `pte_alloc_one':
/usr/src/linux/include/asm/pgalloc.h:113: warning: implicit declaration of function `mmx_clear_page_Rsmp_d0c312ff'
/usr/src/linux/include/asm/pgalloc.h: In function `pte_alloc_one_fast':
/usr/src/linux/include/asm/pgalloc.h:122: `cpu_data_Rsmp_d3b73c3c' undeclared (first use in this function)
/usr/src/linux/include/asm/pgalloc.h: In function `pte_free_fast':
/usr/src/linux/include/asm/pgalloc.h:132: `cpu_data_Rsmp_d3b73c3c' undeclared (first use in this function)
In file included from /usr/src/linux/include/linux/vmalloc.h:8,
                 from /usr/src/linux/include/asm/io.h:47,
                 from schar.c:26:
/usr/src/linux/include/linux/highmem.h: In function `copy_user_highpage':
/usr/src/linux/include/linux/highmem.h:119: warning: implicit declaration of function `mmx_copy_page_Rsmp_ecb52bbc'
make: *** [schar.o] Error 1

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I would like to be able to compile and mess with this code so any help would be appreciated.

thanks
chris

I have the same question. Could someone give some suggestion?

$su root

then run the command to make the object.