2 * This file is part of the coreboot project.
4 * Copyright (C) 2008-2010 coresystems GmbH
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; version 2 of
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
22 // Make sure no stage 2 code is included:
25 /* On AMD's platforms we can set SMBASE by writing an MSR */
26 #if !CONFIG_NORTHBRIDGE_AMD_AMDK8 && !CONFIG_NORTHBRIDGE_AMD_AMDFAM10
28 // FIXME: Is this piece of code southbridge specific, or
29 // can it be cleaned up so this include is not required?
30 // It's needed right now because we get our DEFAULT_PMBASE from
32 #if CONFIG_SOUTHBRIDGE_INTEL_I82801GX
33 #include "../../../southbridge/intel/i82801gx/i82801gx.h"
34 #elif CONFIG_SOUTHBRIDGE_INTEL_I82801DX
35 #include "../../../southbridge/intel/i82801dx/i82801dx.h"
36 #elif CONFIG_SOUTHBRIDGE_INTEL_SCH
37 #include "../../../southbridge/intel/sch/sch.h"
39 #error "Southbridge needs SMM handler support."
44 #include <cpu/x86/mtrr.h>
46 #endif /* CONFIG_SMM_TSEG */
48 #define LAPIC_ID 0xfee00020
50 .global smm_relocation_start
51 .global smm_relocation_end
53 /* initially SMM is some sort of real mode. */
57 * When starting up, x86 CPUs have their SMBASE set to 0x30000. However,
58 * this is not a good place for the SMM handler to live, so it needs to
60 * Traditionally SMM handlers used to live in the A segment (0xa0000).
61 * With growing SMM handlers, more CPU cores, etc. CPU vendors started
62 * allowing to relocate the handler to the end of physical memory, which
63 * they refer to as TSEG.
64 * This trampoline code relocates SMBASE to base address - ( lapicid * 0x400 )
66 * Why 0x400? It is a safe value to cover the save state area per CPU. On
67 * current AMD CPUs this area is _documented_ to be 0x200 bytes. On Intel
68 * Core 2 CPUs the _documented_ parts of the save state area is 48 bytes
69 * bigger, effectively sizing our data structures 0x300 bytes.
71 * Example (with SMM handler living at 0xa0000):
73 * LAPICID SMBASE SMM Entry SAVE STATE
74 * 0 0xa0000 0xa8000 0xafd00
75 * 1 0x9fc00 0xa7c00 0xaf900
76 * 2 0x9f800 0xa7800 0xaf500
77 * 3 0x9f400 0xa7400 0xaf100
78 * 4 0x9f000 0xa7000 0xaed00
79 * 5 0x9ec00 0xa6c00 0xae900
80 * 6 0x9e800 0xa6800 0xae500
81 * 7 0x9e400 0xa6400 0xae100
82 * 8 0x9e000 0xa6000 0xadd00
83 * 9 0x9dc00 0xa5c00 0xad900
84 * 10 0x9d800 0xa5800 0xad500
85 * 11 0x9d400 0xa5400 0xad100
86 * 12 0x9d000 0xa5000 0xacd00
87 * 13 0x9cc00 0xa4c00 0xac900
88 * 14 0x9c800 0xa4800 0xac500
89 * 15 0x9c400 0xa4400 0xac100
93 * 31 0x98400 0xa0400 0xa8100
95 * With 32 cores, the SMM handler would need to fit between
96 * 0xa0000-0xa0400 and the stub plus stack would need to go
97 * at 0xa8000-0xa8100 (example for core 0). That is not enough.
99 * This means we're basically limited to 16 cpu cores before
100 * we need to move the SMM handler to TSEG.
102 * Note: Some versions of Pentium M need their SMBASE aligned to 32k.
103 * On those the above only works for up to 2 cores. But for now we only
104 * care fore Core (2) Duo/Solo
108 smm_relocation_start:
109 /* Check revision to see if AMD64 style SMM_BASE
110 * Intel Core Solo/Duo: 0x30007
111 * Intel Core2 Solo/Duo: 0x30100
112 * Intel SandyBridge: 0x30101
114 * This check does not make much sense, unless someone ports
115 * SMI handling to AMD64 CPUs.
118 mov $0x38000 + 0x7efc, %ebx
119 addr32 mov (%ebx), %al
123 mov $0x38000 + 0x7ef8, %ebx
126 mov $0x38000 + 0x7f00, %ebx
129 /* Get this CPU's LAPIC ID */
131 addr32 movl (%esi), %ecx
134 /* calculate offset by multiplying the
135 * apic ID by 1024 (0x400)
141 movl $(TSEG_BAR), %ecx /* Get TSEG base from PCIE */
142 addr32 movl (%ecx), %eax /* Save TSEG_BAR in %eax */
143 andl $~1, %eax /* Remove lock bit */
147 subl %edx, %eax /* subtract offset, see above */
149 addr32 movl %eax, (%ebx)
152 /* Check for SMRR capability in MTRRCAP[11] */
153 movl $MTRRcap_MSR, %ecx
159 movl $(TSEG_BAR), %ecx /* Get TSEG base from PCIE */
160 addr32 movl (%ecx), %eax /* Save TSEG_BAR in %eax */
161 andl $~1, %eax /* Remove lock bit */
164 /* Set SMRR base address. */
165 movl $SMRRphysBase_MSR, %ecx
166 orl $MTRR_TYPE_WRBACK, %eax
171 movl $SMRRphysMask_MSR, %ecx
172 movl $(~(CONFIG_SMM_TSEG_SIZE - 1) | MTRRphysMaskValid), %eax
176 #if CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE || CONFIG_NORTHBRIDGE_INTEL_IVYBRIDGE
178 * IED base is top 4M of TSEG
180 addl $(CONFIG_SMM_TSEG_SIZE - IED_SIZE), %ebx
181 movl $(0x30000 + 0x8000 + 0x7eec), %eax
182 addr32 movl %ebx, (%eax)
188 /* The next section of code is potentially southbridge specific */
190 /* Clear SMI status */
191 movw $(DEFAULT_PMBASE + 0x34), %dx
195 /* Clear PM1 status */
196 movw $(DEFAULT_PMBASE + 0x00), %dx
200 /* Set EOS bit so other SMIs can occur */
201 movw $(DEFAULT_PMBASE + 0x30), %dx
206 /* End of southbridge specific section. */
208 #if CONFIG_DEBUG_SMM_RELOCATION
209 /* print [SMM-x] so we can determine if CPUx went to SMM */
210 movw $CONFIG_TTYS0_BASE, %dx
220 /* calculate ascii of cpu number. More than 9 cores? -> FIXME */
232 /* That's it. return */