From c2d55efd8a9a156fe14fd477924fadb765ac9438 Mon Sep 17 00:00:00 2001
Message-Id: <c2d55efd8a9a156fe14fd477924fadb765ac9438.1387280747.git.minovotn@redhat.com>
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Wed, 11 Dec 2013 15:16:27 +0100
Subject: [PATCH 1/3] biostables: support looking up RSDP

RH-Author: Michael S. Tsirkin <mst@redhat.com>
Message-id: <1386774929-25693-2-git-send-email-mst@redhat.com>
Patchwork-id: 56224
O-Subject: [RHEL7.0 seabios PATCH 1/3] biostables: support looking up RSDP
Bugzilla: 1034877
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Marcel Apfelbaum <marcel.a@redhat.com>

Will be used when it's loaded from QEMU.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry-picked from commit ff5f7921d904dd2ddbaded3941643da8ba5fa9aa)

In rhel7 codebase we don't know the exact fseg
range. Just scan all of the ROM range.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 src/util.h       |  1 +
 src/biostables.c | 41 ++++++++++++++++++++++++++++++++++-------
 2 files changed, 35 insertions(+), 7 deletions(-)

Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
 src/biostables.c | 41 ++++++++++++++++++++++++++++++++++-------
 src/util.h       |  1 +
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/src/biostables.c b/src/biostables.c
index 81cc79b..2352ba4 100644
--- a/src/biostables.c
+++ b/src/biostables.c
@@ -57,22 +57,35 @@ copy_mptable(void *pos)
     memcpy((void*)newpos + length, (void*)p->physaddr, mpclength);
 }
 
-static void
-copy_acpi_rsdp(void *pos)
+static int
+get_acpi_rsdp_length(void *pos, unsigned size)
 {
-    if (RsdpAddr)
-        return;
     struct rsdp_descriptor *p = pos;
     if (p->signature != RSDP_SIGNATURE)
-        return;
+        return -1;
     u32 length = 20;
+    if (length > size)
+        return -1;
     if (checksum(pos, length) != 0)
-        return;
+        return -1;
     if (p->revision > 1) {
         length = p->length;
+        if (length > size)
+            return -1;
         if (checksum(pos, length) != 0)
-            return;
+            return -1;
     }
+    return length;
+}
+
+static void
+copy_acpi_rsdp(void *pos)
+{
+    if (RsdpAddr)
+        return;
+    int length = get_acpi_rsdp_length(pos, -1);
+    if (length < 0)
+        return;
     void *newpos = malloc_fseg(length);
     if (!newpos) {
         warn_noalloc();
@@ -115,3 +128,17 @@ copy_table(void *pos)
     copy_acpi_rsdp(pos);
     copy_smbios(pos);
 }
+
+void *find_acpi_rsdp(void)
+{
+    /* The BIOS read-only memory space is between 0E0000h and 0FFFFFh. */
+    unsigned long start = 0xE0000;
+    unsigned long end = 0xFFFFF;
+    unsigned long pos;
+
+    for (pos = ALIGN(start, 0x10); pos <= ALIGN_DOWN(end, 0x10); pos += 0x10)
+        if (get_acpi_rsdp_length((void *)pos, end - pos) >= 0)
+            return (void *)pos;
+
+    return NULL;
+}
diff --git a/src/util.h b/src/util.h
index 7723bb1..e46d298 100644
--- a/src/util.h
+++ b/src/util.h
@@ -339,6 +339,7 @@ void coreboot_cbfs_setup(void);
 
 // biostable.c
 void copy_table(void *pos);
+void *find_acpi_rsdp(void);
 
 // vgahooks.c
 void handle_155f(struct bregs *regs);
-- 
1.7.11.7