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Date: Thu, 23 Sep 2010 17:28:46 +0100 (BST)
From: Daniel Drake <dsd@...top.org>
To: x86@...nel.org
Cc: dilinger@...ued.net
Subject: [PATCH 2/2] OLPC: Rework BIOS signature check
The XO-1.5 laptop is not currently detected as an OLPC machine because
it fails this XO-1-centric check.
Now that we have OLPC OFW support in the kernel, a more sensible
check is to see if we found OFW during boot and check the architecture
property.
Also remove a now-meaningless codepath, as we're always going to have
OFW support with OLPC.
Signed-off-by: Daniel Drake <dsd@...top.org>
---
Replaces earlier patch: [PATCH 3/3] OLPC: Extend BIOS signature check
Now checks OFW's architecture property to be really sure that we're
running on an OLPC laptop.
arch/x86/Kconfig | 3 +-
arch/x86/include/asm/olpc_ofw.h | 4 +++
arch/x86/kernel/olpc.c | 58 +++++++++++++++++----------------------
arch/x86/kernel/olpc_ofw.c | 6 ++++
4 files changed, 37 insertions(+), 34 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0ed4c9b..c255255 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2061,6 +2061,7 @@ config SCx200HR_TIMER
config OLPC
bool "One Laptop Per Child support"
select GPIOLIB
+ select OLPC_OPENFIRMWARE
---help---
Add support for detecting the unique features of the OLPC
XO hardware.
@@ -2068,7 +2069,7 @@ config OLPC
config OLPC_OPENFIRMWARE
bool "Support for OLPC's Open Firmware"
depends on !X86_64 && !X86_PAE
- default y if OLPC
+ default n
help
This option adds support for the implementation of Open Firmware
that is used on the OLPC XO-1 Children's Machine.
diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
index 08fde47..2a84781 100644
--- a/arch/x86/include/asm/olpc_ofw.h
+++ b/arch/x86/include/asm/olpc_ofw.h
@@ -21,10 +21,14 @@ extern void olpc_ofw_detect(void);
/* install OFW's pde permanently into the kernel's pgtable */
extern void setup_olpc_ofw_pgd(void);
+/* check if OFW was detected during boot */
+extern bool olpc_ofw_present(void);
+
#else /* !CONFIG_OLPC_OPENFIRMWARE */
static inline void olpc_ofw_detect(void) { }
static inline void setup_olpc_ofw_pgd(void) { }
+static inline bool olpc_ofw_present(void) { return false; }
#endif /* !CONFIG_OLPC_OPENFIRMWARE */
diff --git a/arch/x86/kernel/olpc.c b/arch/x86/kernel/olpc.c
index 635888c..37c49934 100644
--- a/arch/x86/kernel/olpc.c
+++ b/arch/x86/kernel/olpc.c
@@ -183,8 +183,21 @@ err:
}
EXPORT_SYMBOL_GPL(olpc_ec_cmd);
-#ifdef CONFIG_OLPC_OPENFIRMWARE
-static void __init platform_detect(void)
+static bool __init check_ofw_architecture(void)
+{
+ size_t propsize;
+ char olpc_arch[5];
+ const void *args[] = { NULL, "architecture", olpc_arch, (void *)5 };
+ void *res[] = { &propsize };
+
+ if (olpc_ofw("getprop", args, res)) {
+ printk(KERN_ERR "ofw: getprop call failed!\n");
+ return false;
+ }
+ return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
+}
+
+static u32 __init get_board_revision(void)
{
size_t propsize;
__be32 rev;
@@ -193,46 +206,27 @@ static void __init platform_detect(void)
if (olpc_ofw("getprop", args, res) || propsize != 4) {
printk(KERN_ERR "ofw: getprop call failed!\n");
- rev = cpu_to_be32(0);
+ return cpu_to_be32(0);
}
- olpc_platform_info.boardrev = be32_to_cpu(rev);
+ return be32_to_cpu(rev);
}
-#else
-static void __init platform_detect(void)
+
+static bool __init platform_detect(void)
{
- /* stopgap until OFW support is added to the kernel */
- olpc_platform_info.boardrev = olpc_board(0xc2);
+ if (!check_ofw_architecture())
+ return false;
+ olpc_platform_info.flags |= OLPC_F_PRESENT;
+ olpc_platform_info.boardrev = get_board_revision();
+ return true;
}
-#endif
static int __init olpc_init(void)
{
- unsigned char *romsig;
-
- /* The ioremap check is dangerous; limit what we run it on */
- if (!is_geode() || cs5535_has_vsa2())
+ if (!olpc_ofw_present() || !platform_detect())
return 0;
spin_lock_init(&ec_lock);
- romsig = ioremap(0xffffffc0, 16);
- if (!romsig)
- return 0;
-
- if (strncmp(romsig, "CL1 Q", 7))
- goto unmap;
- if (strncmp(romsig+6, romsig+13, 3)) {
- printk(KERN_INFO "OLPC BIOS signature looks invalid. "
- "Assuming not OLPC\n");
- goto unmap;
- }
-
- printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);
- olpc_platform_info.flags |= OLPC_F_PRESENT;
-
- /* get the platform revision */
- platform_detect();
-
/* assume B1 and above models always have a DCON */
if (olpc_board_at_least(olpc_board(0xb1)))
olpc_platform_info.flags |= OLPC_F_DCON;
@@ -254,8 +248,6 @@ static int __init olpc_init(void)
olpc_platform_info.boardrev >> 4,
olpc_platform_info.ecver);
-unmap:
- iounmap(romsig);
return 0;
}
diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
index 3218aa7..7873204 100644
--- a/arch/x86/kernel/olpc_ofw.c
+++ b/arch/x86/kernel/olpc_ofw.c
@@ -74,6 +74,12 @@ int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
}
EXPORT_SYMBOL_GPL(__olpc_ofw);
+bool olpc_ofw_present(void)
+{
+ return olpc_ofw_cif != NULL;
+}
+EXPORT_SYMBOL_GPL(olpc_ofw_present);
+
/* OFW cif _should_ be above this address */
#define OFW_MIN 0xff000000
--
1.7.2.2
--
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