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update for mooc OS labs

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yuchen
2015-01-30 20:20:30 +08:00
parent 6a4eb1f465
commit 87059df293
57 changed files with 586 additions and 129 deletions
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8
labcodes_answer/lab1_result/boot/bootasm.S
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@@ -27,20 +27,20 @@ start:
# address line 20 is tied low, so that addresses higher than
# 1MB wrap around to zero by default. This code undoes this.
seta20.1:
inb $0x64, %al # Wait for not busy
inb $0x64, %al # Wait for not busy(8042 input buffer empty).
testb $0x2, %al
jnz seta20.1
movb $0xd1, %al # 0xd1 -> port 0x64
outb %al, $0x64
outb %al, $0x64 # 0xd1 means: write data to 8042's P2 port
seta20.2:
inb $0x64, %al # Wait for not busy
inb $0x64, %al # Wait for not busy(8042 input buffer empty).
testb $0x2, %al
jnz seta20.2
movb $0xdf, %al # 0xdf -> port 0x60
outb %al, $0x60
outb %al, $0x60 # 0xdf = 11011111, means set P2's A20 bit(the 1 bit) to 1
# Switch from real to protected mode, using a bootstrap GDT
# and segment translation that makes virtual addresses