New patch to review for coreboot: 31004ca cbmem console: Locate the preram console with a symbol instead of a section.

[Isaac Christensen]

Isaac Christensen ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/7013

-gerrit

commit 31004ca3bd259f400bbeb1a9b3d866e9c09f5623
Author: Gabe Black 
Date:   Wed Apr 2 17:57:05 2014 -0700

cbmem console: Locate the preram console with a symbol instead of a section.

On non-x86 systems, the location of the preram CBMEM console may not be in a
    predictable place relative to other things in the linker script. That makes it
    difficult to work with as its own section because the linker will complain if
    you try to move backwards as it lays out memory. If the console header is
    treated as an actual blob of memory which has to be put in the image, we'd
    have to predict where to put it so that it isn't before something with a lower
    address or after something with a higher address. Symbols, on the other hand,
    can be defined arbitrarily.

Change-Id: I3257b981eee0c15bb997a9f2c55a03494c6ec6f0
    Signed-off-by: Gabe Black 
    Reviewed-on: https://chromium-review.googlesource.com/193164
    Reviewed-by: Tom Warren 
    Reviewed-by: Aaron Durbin 
    Commit-Queue: Gabe Black 
    Tested-by: Gabe Black 
    (cherry picked from commit a492761c27076bcac080013d509ae4aafd6dc3e3)
    Signed-off-by: Isaac Christensen 
---
 src/arch/arm/include/arch/early_variables.h |  1 -
 src/arch/x86/include/arch/early_variables.h |  2 --
 src/arch/x86/init/romstage.ld               | 14 +++++++-------
 src/console/Kconfig                         | 10 +++++-----
 src/lib/cbmem_console.c                     |  5 +++--
 5 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/src/arch/arm/include/arch/early_variables.h b/src/arch/arm/include/arch/early_variables.h
index 041d0ae..5b58baa 100644
--- a/src/arch/arm/include/arch/early_variables.h
+++ b/src/arch/arm/include/arch/early_variables.h
@@ -21,7 +21,6 @@
 #define ARCH_EARLY_VARIABLES_H

#define CAR_GLOBAL
-#define CAR_CBMEM

#define CAR_MIGRATE(migrate_fn_)
 static inline void *car_get_var_ptr(void *var) { return var; }
diff --git a/src/arch/x86/include/arch/early_variables.h b/src/arch/x86/include/arch/early_variables.h
index ea1a133..80e82d6 100644
--- a/src/arch/x86/include/arch/early_variables.h
+++ b/src/arch/x86/include/arch/early_variables.h
@@ -26,10 +26,8 @@ asm(".previous");
 asm(".section .car.cbmem_console,"w",@nobits");
 asm(".previous");
 #define CAR_GLOBAL __attribute__((section(".car.global_data")))
-#define CAR_CBMEM __attribute__((section(".car.cbmem_console")))
 #else
 #define CAR_GLOBAL
-#define CAR_CBMEM
 #endif

#if defined(__PRE_RAM__)
diff --git a/src/arch/x86/init/romstage.ld b/src/arch/x86/init/romstage.ld
index 5458cfc..d6eb511 100644
--- a/src/arch/x86/init/romstage.ld
+++ b/src/arch/x86/init/romstage.ld
@@ -55,15 +55,15 @@ SECTIONS
    .car.data . (NOLOAD) : {
    	_car_data_start = .;
    	*(.car.global_data);
-		/* The cbmem_console section comes last to take advantage of
-		 * a zero-sized array to hold the memconsole contents that
-		 * grows to a bound of CONFIG_CONSOLE_CAR_BUFFER_SIZE. However,
-		 * collisions within the cache-as-ram region cannot be
+		_car_data_end = .;
+		/* The preram cbmem console area comes last to take advantage
+		 * of a zero-sized array to hold the memconsole contents that
+		 * grows to a bound of CONFIG_CONSOLE_PRERAM_BUFFER_SIZE.
+		 * However, collisions within the cache-as-ram region cannot be
    	 * statically checked because the cache-as-ram region usage is
    	 * cpu/chipset dependent. */
-		*(.car.cbmem_console);
-		_car_data_end = .;
+		preram_cbmem_console = .;
    }

-	_bogus = ASSERT((SIZEOF(.car.data) <= CONFIG_DCACHE_RAM_SIZE), "Cache as RAM area is too full");
+	_bogus = ASSERT((SIZEOF(.car.data) + CONFIG_CONSOLE_PRERAM_BUFFER_SIZE <= CONFIG_DCACHE_RAM_SIZE), "Cache as RAM area is too full");
 }
diff --git a/src/console/Kconfig b/src/console/Kconfig
index 472ac5c..619af56 100644
--- a/src/console/Kconfig
+++ b/src/console/Kconfig
@@ -184,15 +184,15 @@ config CONSOLE_CBMEM_BUFFER_SIZE
      value (128K or 0x20000 bytes) is large enough to accommodate
      even the BIOS_SPEW level.

-config CONSOLE_CAR_BUFFER_SIZE
+config CONSOLE_PRERAM_BUFFER_SIZE
    depends on CONSOLE_CBMEM
-	hex "Room allocated for console output in Cache as RAM"
+	hex "Room allocated for console output before RAM is initialized"
    default 0xc00
    help
      Console is used before RAM is initialized. This is the room reserved
-	  in the DCACHE based RAM to keep console output before it can be
-	  saved in a CBMEM buffer. 3K bytes should be enough even for the
-	  BIOS_SPEW level.
+	  in the DCACHE based RAM, SRAM, etc. to keep console output before it
+	  can be saved in a CBMEM buffer. 3K bytes should be enough even for
+	  the BIOS_SPEW level.

config CONSOLE_QEMU_DEBUGCON
    bool "QEMU debug console output"
diff --git a/src/lib/cbmem_console.c b/src/lib/cbmem_console.c
index 9d5419a..b5b75f3 100644
--- a/src/lib/cbmem_console.c
+++ b/src/lib/cbmem_console.c
@@ -44,7 +44,7 @@ static struct cbmem_console *cbmem_console_p CAR_GLOBAL;
  * the area are defined in the config.
  */

-static struct cbmem_console car_cbmem_console CAR_CBMEM;
+extern struct cbmem_console preram_cbmem_console;

#else

@@ -86,7 +86,8 @@ static inline void init_console_ptr(void *storage, u32 total_space)
 void cbmemc_init(void)
 {
 #ifdef __PRE_RAM__
-	init_console_ptr(&car_cbmem_console, CONFIG_CONSOLE_CAR_BUFFER_SIZE);
+	init_console_ptr(&preram_cbmem_console,
+			 CONFIG_CONSOLE_PRERAM_BUFFER_SIZE);
 #else
    /*
     * Initializing before CBMEM is available, use static buffer to store