39 lines
1.2 KiB
C
39 lines
1.2 KiB
C
/* The kernel call implemented in this file:
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* m_type: SYS_READBIOS
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*
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* The parameters for this kernel call are:
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* m_lsys_krn_readbios.size number of bytes to copy
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* m_lsys_krn_readbios.addr absolute address in BIOS area
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* m_lsys_krn_readbios.buf buffer address in requesting process
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*/
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#include "kernel/system.h"
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#include <minix/type.h>
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/*===========================================================================*
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* do_readbios *
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*===========================================================================*/
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int do_readbios(struct proc * caller, message * m_ptr)
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{
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struct vir_addr src, dst;
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size_t len = m_ptr->m_lsys_krn_readbios.size;
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vir_bytes limit;
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src.offset = m_ptr->m_lsys_krn_readbios.addr;
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dst.offset = m_ptr->m_lsys_krn_readbios.buf;
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src.proc_nr_e = NONE;
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dst.proc_nr_e = m_ptr->m_source;
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limit = src.offset + len - 1;
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#define VINRANGE(v, a, b) ((a) <= (v) && (v) <= (b))
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#define SUBRANGE(a,b,c,d) (VINRANGE((a), (c), (d)) && VINRANGE((b),(c),(d)))
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#define USERRANGE(a, b) SUBRANGE(src.offset, limit, (a), (b))
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if(!USERRANGE(BIOS_MEM_BEGIN, BIOS_MEM_END) &&
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!USERRANGE(BASE_MEM_TOP, UPPER_MEM_END))
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return EPERM;
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return virtual_copy_vmcheck(caller, &src, &dst, m_ptr->m_lsys_krn_readbios.size);
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}
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