Make sure ACPI structures are byte-aligned

Apparently, guests are very tolerant of corrupt ACPI tables because our 
tables have been badly corrupted for some time now.  A version of 
Knoppix using a 2.6.11 kernel refused to boot and it turned out it was 
due to the interrupt override table introduced by the recent HPET 
commit.

This patch updates the BIOS and introduces a patch to pack the ACPI 
tables.  If you have a guest that used to work and is broken by the this 
commit, let me know.  We have some weird hacks in the tables that I 
suspect are work arounds for this bug.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6108 c046a42c-6fe2-441c-8c8c-71466251a162

3 files changed, 37 insertions, 0 deletions

diff --git a/pc-bios/bios-pq/0006_acpi-packing.patch b/pc-bios/bios-pq/0006_acpi-packing.patch
new file mode 100644
index 000000000..0037046a6
--- /dev/null
+++ b/pc-bios/bios-pq/0006_acpi-packing.patch
@@ -0,0 +1,36 @@
+Make ACPI tables byte-aligned
+
+The ACPI spec requires structures to be byte-aligned.  I'm a bit surprised we've
+gotten away with this for so long.  This patch allows Knoppix to boot.  This bug
+was reported by Paul Brook.
+
+Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
+
+diff --git a/bios/rombios32.c b/bios/rombios32.c
+index 7953485..540912a 100644
+--- a/bios/rombios32.c
++++ b/bios/rombios32.c
+@@ -1099,6 +1099,12 @@ static void mptable_init(void)
+ /* Table structure from Linux kernel (the ACPI tables are under the
+    BSD license) */
+ 
++/*
++ * All tables must be byte-packed to match the ACPI specification, since
++ * the tables are provided by the system BIOS.
++ */
++#pragma pack(1)
++
+ #define ACPI_TABLE_HEADER_DEF   /* ACPI common table header */ \
+ 	uint8_t                            signature [4];          /* ACPI signature (4 ASCII characters) */\
+ 	uint32_t                             length;                 /* Length of table, in bytes, including header */\
+@@ -1326,6 +1332,10 @@ struct madt_int_override
+ };
+ #endif
+ 
++/* Reset to default packing */
++
++#pragma pack()
++
+ #include "acpi-dsdt.hex"
+ 
+ static inline uint16_t cpu_to_le16(uint16_t x)
diff --git a/pc-bios/bios-pq/series b/pc-bios/bios-pq/series
index beff2c6d4..b53157ecd 100644
--- a/pc-bios/bios-pq/series
+++ b/pc-bios/bios-pq/series
@@ -3,3 +3,4 @@
 0003_smp-startup-poll.patch
 0004_no-stack-protector.patch
 0005_hpet.patch
+0006_acpi-packing.patch
diff --git a/pc-bios/bios.bin b/pc-bios/bios.bin
index c401d25ca..1d987d0bf 100644
--- a/pc-bios/bios.bin
+++ b/pc-bios/bios.bin