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.code16
#define SMAP 0x534d4150
#define E820_BIOS_MAX 128
get_memory_map:
xorl %ebx, %ebx # continuation counter
movw $bootsym(bios_e820map), %di # point into the whitelist
# so we can have the bios
# directly write into it.
1: movl $0x0000e820, %eax # e820, upper word zeroed
movl $SMAP,%edx # ascii 'SMAP'
movl $20,%ecx # size of the e820rec
pushw %ds # data record.
popw %es
int $0x15
jc .Ldone
cmpl $SMAP,%eax # check the return is `SMAP'
jne .Ldone
incw bootsym(bios_e820nr)
cmpw $E820_BIOS_MAX, bootsym(bios_e820nr) # up to this many entries
jae .Ldone
addw $20,%di
testl %ebx,%ebx # check to see if
jnz 1b # %ebx is set to EOF
.Ldone:
ret
.align 4
GLOBAL(bios_e820map)
.fill E820_BIOS_MAX*20,1,0
GLOBAL(bios_e820nr)
.long 0
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