Author: hailfinger
Date: 2008-08-18 18:54:12 +0200 (Mon, 18 Aug 2008)
New Revision: 785
Modified:
coreboot-v3/arch/x86/amd/stage0.S
coreboot-v3/arch/x86/geodelx/stage0.S
coreboot-v3/arch/x86/stage0_i586.S
coreboot-v3/arch/x86/stage1.c
coreboot-v3/include/console.h
Log:
Move stage1 global variable management from asm to C. The stage0 asm
code now unconditionally pushes an empty pointer to the stack which is a
placeholder for the pointer to global variable storage. That pointer and
the global variable storage are initialized in global_vars_init().
Creating global variables is now a piece of cake. You don't even have to
touch any asm code, just add them to struct global_vars.
Build tested on all targets, boot tested on Qemu.
NOTES:
- The code is not yet MP safe, but that's due to v3 not being MP safe in
general (and the comments contradict the code regarding MP features).
- K8 code now works by accident.
Signed-off-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
Acked-by: Segher Boessenkool <[EMAIL PROTECTED]>
Modified: coreboot-v3/arch/x86/amd/stage0.S
===================================================================
--- coreboot-v3/arch/x86/amd/stage0.S 2008-08-18 16:48:27 UTC (rev 784)
+++ coreboot-v3/arch/x86/amd/stage0.S 2008-08-18 16:54:12 UTC (rev 785)
@@ -23,7 +23,9 @@
#define CacheBase CONFIG_CARBASE
#define MEM_TOPK 2048
-/* leave some space for global variable to pass to RAM stage */
+/* Leave some space for a pointer to the global variables.
+ * This should most likely be 4.
+ */
#define GlobalVarSize 32
#ifdef CONFIG_CPU_AMD_K10
Modified: coreboot-v3/arch/x86/geodelx/stage0.S
===================================================================
--- coreboot-v3/arch/x86/geodelx/stage0.S 2008-08-18 16:48:27 UTC (rev
784)
+++ coreboot-v3/arch/x86/geodelx/stage0.S 2008-08-18 16:54:12 UTC (rev
785)
@@ -361,13 +361,10 @@
movw %ax, %ss
lout:
-#ifdef CONFIG_CONSOLE_BUFFER
- /* Store pointer to start of printk buffer, should really use
- * PRINTK_BUF_ADDR_CAR instead.
- */
- movl $CONFIG_CARBASE, %eax
- pushl %eax /* printk buffer */
-#endif
+ /* Store zero for the pointer to the global variables. */
+ movl $0, %eax
+ pushl %eax
+
/* Restore the BIST result. */
movl %ebp, %eax
Modified: coreboot-v3/arch/x86/stage0_i586.S
===================================================================
--- coreboot-v3/arch/x86/stage0_i586.S 2008-08-18 16:48:27 UTC (rev 784)
+++ coreboot-v3/arch/x86/stage0_i586.S 2008-08-18 16:54:12 UTC (rev 785)
@@ -435,13 +435,10 @@
movw %ax, %ss
lout:
-#ifdef CONFIG_CONSOLE_BUFFER
- /* Store pointer to start of printk buffer, should really use
- * PRINTK_BUF_ADDR_CAR instead.
- */
- movl $CONFIG_CARBASE, %eax
- pushl %eax /* printk buffer */
-#endif
+ /* Store zero for the pointer to the global variables. */
+ movl $0, %eax
+ pushl %eax
+
/* Restore the BIST result */
movl %ebp, %eax
/* We need to set ebp ? No need */
Modified: coreboot-v3/arch/x86/stage1.c
===================================================================
--- coreboot-v3/arch/x86/stage1.c 2008-08-18 16:48:27 UTC (rev 784)
+++ coreboot-v3/arch/x86/stage1.c 2008-08-18 16:54:12 UTC (rev 785)
@@ -82,9 +82,15 @@
struct global_vars *global_vars(void)
{
- return (struct global_vars *)(bottom_of_stack() - sizeof(struct
global_vars));
+ return *(struct global_vars **)(bottom_of_stack() - sizeof(struct
global_vars *));
}
+void global_vars_init(struct global_vars *globvars)
+{
+ memset(globvars, 0, sizeof(struct global_vars));
+ *(struct global_vars **)(bottom_of_stack() - sizeof(struct global_vars
*)) = globvars;
+}
+
void dump_mem_range(int msg_level, unsigned char *buf, int size)
{
int i;
@@ -119,9 +125,11 @@
/*
* This function is called from assembler code with its argument on the
* stack. Force the compiler to generate always correct code for this case.
+ * We have cache as ram running and can start executing code in C.
*/
void __attribute__((stdcall)) stage1_main(u32 bist)
{
+ struct global_vars globvars;
int ret;
struct mem_file archive;
void *entry;
@@ -150,10 +158,13 @@
stop_ap();
}
- // We have cache as ram running and can start executing code in C.
+ /* Initialize global variables before we can think of using them.
+ * NEVER run this on an AP!
+ */
+ global_vars_init(&globvars);
#ifdef CONFIG_CONSOLE_BUFFER
- /* Initialize the printk buffer. */
+ /* Initialize the printk buffer. NEVER run this on an AP! */
printk_buffer_init();
#endif
Modified: coreboot-v3/include/console.h
===================================================================
--- coreboot-v3/include/console.h 2008-08-18 16:48:27 UTC (rev 784)
+++ coreboot-v3/include/console.h 2008-08-18 16:54:12 UTC (rev 785)
@@ -60,10 +60,10 @@
#endif
/*
- * If you change struct global_vars in any way, you have to fix all stage0 asm
- * code. The stage0 asm code modification is nontrivial (size of the struct,
- * alignment, initialization, order of struct members, initialization).
- * Depending on your compiler, real breakage may happen.
+ * struct global_vars is managed entirely from C code. Keep in mind that there
+ * is NO buffer at the end of the struct, so having zero-sized arrays at the
+ * end or similar stuff for which the compiler can't determine the final size
+ * will corrupt memory. If you don't try to be clever, everything will be fine.
*/
struct global_vars {
#ifdef CONFIG_CONSOLE_BUFFER
--
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