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X86: Make exceptions handle stack switching.

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This commit is contained in:
Gabe Black 2009-02-25 10:17:19 -08:00
parent aa7bc1be74
commit 99aa121fca
1 changed files with 14 additions and 13 deletions
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27
src/arch/x86/isa/insts/romutil.py
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@ -80,29 +80,22 @@ def rom
andi t10, t10, 3, dataSize=8
rdattr t5, cs, dataSize=8
srli t5, t5, 3, dataSize=8
sub t5, t5, t10, dataSize=8
andi t0, t5, 0x3, flags=(EZF,), dataSize=8
andi t5, t5, 0x3, dataSize=8
sub t0, t5, t10, flags=(EZF,), dataSize=8
# We're going to change priviledge, so zero out the stack selector. We
# need to let the IST have priority so we don't branch yet.
wrsel t11, t0, flags=(nCEZF,)
# Check the IST field of the gate descriptor
srli t10, t4, 32, dataSize=8
andi t10, t10, 0x7, dataSize=8
subi t0, t10, 1, flags=(ECF,), dataSize=8
srli t12, t4, 32, dataSize=8
andi t12, t12, 0x7, dataSize=8
subi t0, t12, 1, flags=(ECF,), dataSize=8
br rom_local_label("%(startLabel)s_istStackSwitch"), flags=(nCECF,)
br rom_local_label("%(startLabel)s_cplStackSwitch"), flags=(nCEZF,)
# If we're here, it's because the stack isn't being switched.
# Set t6 to the new aligned rsp.
mov t6, t6, rsp, dataSize=8
andi t6, t6, 0xF0, dataSize=1
subi t6, t6, 40 + %(errorCodeSize)d, dataSize=8
# Check that we can access everything we need to on the stack
ldst t0, hs, [1, t0, t6], dataSize=8, addressSize=8
ldst t0, hs, [1, t0, t6], \
32 + %(errorCodeSize)d, dataSize=8, addressSize=8
br rom_local_label("%(startLabel)s_stackSwitched")
%(startLabel)s_istStackSwitch:
@ -110,10 +103,18 @@ def rom
br rom_local_label("%(startLabel)s_stackSwitched")
%(startLabel)s_cplStackSwitch:
panic "CPL change initiated stack switching isn't implemented"
# Get the new rsp from the TSS
ld t6, tr, [8, t10, t0], 4, dataSize=8, addressSize=8
%(startLabel)s_stackSwitched:
andi t6, t6, 0xF0, dataSize=1
subi t6, t6, 40 + %(errorCodeSize)d, dataSize=8
# Check that we can access everything we need to on the stack
ldst t0, hs, [1, t0, t6], dataSize=8, addressSize=8
ldst t0, hs, [1, t0, t6], \
32 + %(errorCodeSize)d, dataSize=8, addressSize=8
##
## Point of no return.