1 /* The kernel call implemented in this file: 2 * m_type: SYS_READBIOS 3 * 4 * The parameters for this kernel call are: 5 * m_lsys_krn_readbios.size number of bytes to copy 6 * m_lsys_krn_readbios.addr absolute address in BIOS area 7 * m_lsys_krn_readbios.buf buffer address in requesting process 8 */ 9 10 #include "kernel/system.h" 11 #include <minix/type.h> 12 13 /*===========================================================================* 14 * do_readbios * 15 *===========================================================================*/ 16 int do_readbios(struct proc * caller, message * m_ptr) 17 { 18 struct vir_addr src, dst; 19 size_t len = m_ptr->m_lsys_krn_readbios.size; 20 vir_bytes limit; 21 22 src.offset = m_ptr->m_lsys_krn_readbios.addr; 23 dst.offset = m_ptr->m_lsys_krn_readbios.buf; 24 src.proc_nr_e = NONE; 25 dst.proc_nr_e = m_ptr->m_source; 26 27 limit = src.offset + len - 1; 28 29 #define VINRANGE(v, a, b) ((a) <= (v) && (v) <= (b)) 30 #define SUBRANGE(a,b,c,d) (VINRANGE((a), (c), (d)) && VINRANGE((b),(c),(d))) 31 #define USERRANGE(a, b) SUBRANGE(src.offset, limit, (a), (b)) 32 33 if(!USERRANGE(BIOS_MEM_BEGIN, BIOS_MEM_END) && 34 !USERRANGE(BASE_MEM_TOP, UPPER_MEM_END)) 35 return EPERM; 36 37 return virtual_copy_vmcheck(caller, &src, &dst, m_ptr->m_lsys_krn_readbios.size); 38 } 39