[Skiboot] [PATCH RFC hostboot] bootconfig: Describe pnor boot flags

[Joel Stanley]

The reserved boot flag is now used by a BMC to signal to the host
firmware that it supports the mbox protocol[1].

Currently this has no affect on Hostboot, but in the future it will be
used by skiboot.  In the future hostboot could chose to use the mbox
protocol to read and write PNOR.

[1] github.com/openbmc/mboxbridge/blob/master/Documentation/mbox_protocol.md

Change-Id: I51bc7878eabc975954371ada838d0a348b12ef9d
Signed-off-by: Joel Stanley <joel.stanley at au1.ibm.com>
---
This patch is for hostboot, but we will have to interpret these flags in
skiboot, so I'm asking for some review here in parallel to submitting it
to the hostboot review process.

Note that this is for the P8 branch only; the P9 version of hostboot
uses mbox unconditionally.

 src/usr/initservice/bootconfig/bootconfig_ast2400.C | 20 ++++++++++++++++++++
 src/usr/initservice/bootconfig/bootconfig_ast2400.H | 17 ++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/usr/initservice/bootconfig/bootconfig_ast2400.C b/src/usr/initservice/bootconfig/bootconfig_ast2400.C
index d0d1a3e746b2..43696088b0d7 100644
--- a/src/usr/initservice/bootconfig/bootconfig_ast2400.C
+++ b/src/usr/initservice/bootconfig/bootconfig_ast2400.C
@@ -171,6 +171,24 @@ void AST2400BootConfig::configureBootOptions(uint8_t i_bootOptions )
             errlCommit(errl,INITSVC_COMP_ID);
         }
     }
+};
+
+// configurePnorDriver()
+// ----------------------------------------------------------------------------
+void AST2400BootConfig::configurePnorDriver( uint8_t i_driver )
+{
+    switch (i_driver) {
+    case MBOX:
+        TRACFCOMP(g_bc_trace,
+                "configurePnorDriver() bmc supports mbox protocol");
+	/* Fall through - no hostboot support for mbox */
+        TRACFCOMP(g_bc_trace,
+                "configurePnorDriver() hb does not support mbox protocol");
+    case SFC:
+        TRACFCOMP(g_bc_trace,
+                "configurePnorDriver() using sfc driver");
+	break;
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -250,6 +268,8 @@ void AST2400BootConfig::processBootFlagsV1( uint8_t i_flags )
 {
     configureBootMode( i_flags & BOOT_MODE_FLAGS );
 
+    configurePnorDriver( i_flags & PNOR_DRIVER_FLAGS );
+
     configureBootOptions( i_flags & BOOT_OPTIONS_FLAGS );
 
     configureHbLogLevel( i_flags & LOG_LEVEL_FLAGS );
diff --git a/src/usr/initservice/bootconfig/bootconfig_ast2400.H b/src/usr/initservice/bootconfig/bootconfig_ast2400.H
index cbe341e2b137..7cf96e095fcc 100644
--- a/src/usr/initservice/bootconfig/bootconfig_ast2400.H
+++ b/src/usr/initservice/bootconfig/bootconfig_ast2400.H
@@ -75,7 +75,7 @@ class AST2400BootConfig : public BootConfig
     enum bootFlagMask_t
     {
         LOG_LEVEL_FLAGS     = 0x07,
-        RESERVED_FLAGS      = 0x08,
+        PNOR_DRIVER_FLAGS   = 0x08,
         BOOT_OPTIONS_FLAGS  = 0x30,
         BOOT_MODE_FLAGS     = 0xC0,
     };
@@ -88,6 +88,13 @@ class AST2400BootConfig : public BootConfig
         ISTEP_MODE         = 0x80,
     };
 
+    // Masks to select pnor driver from config register
+    enum pnorDriver
+    {
+        SFC                = 0x00,
+        MBOX               = 0x08,
+    };
+
     // Masks to test boot options flags from config register
     enum bootOptionsFlags
     {
@@ -179,6 +186,14 @@ public:
      */
     void configureBootMode( uint8_t i_mode );
 
+    /**
+     * @brief Process the pnor driver mode from the boot flags register.
+     *
+     * @param[i] i_driver - pnor driver as set in the boot flags reg.
+     *
+     */
+    void configurePnorDriver( uint8_t i_driver );
+
     /**
      * @brief Process boot options from boot flags register
      *
-- 
2.15.1