On 14.10.2008 21:15, Peter Stuge wrote:
> Carl-Daniel Hailfinger wrote:
>
>>>> I believe the stage0_main name is misleading. After all, stage0
>>>> is pure asm and lives in its own .S file.
>>>>
>>> let's call it stage1 then and main()
>>>
>> Works for me.
>>
>
> I'm afraid I don't like that.
>
> Please suggest something that makes the timeline obvious.
> I think we already have other problems like this in v3.
>
> I would be OK with adding phases to stage1 e.g. but I have also
> contemplated flattening the stage/phase tree to only have stages and
> no phases - though that doesn't have to happen right now.
>
OK, so can we settle on phases?
old -> new
stage1_main before disable_car-> stage1_phase1
disable_car and stack switch -> stage1_phase2
stage1_main after stack switch -> stage1_phase3
And yes, I'm aware that the patch below doesn't change the corresponding
asm code yet. I'll work on that as soon as we have agreed on stage1_*
naming.
Signed-off-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
Index: corebootv3-stackrebuild/arch/x86/stage1.c
===================================================================
--- corebootv3-stackrebuild/arch/x86/stage1.c (Revision 925)
+++ corebootv3-stackrebuild/arch/x86/stage1.c (Arbeitskopie)
@@ -143,6 +143,9 @@
return ret;
}
+void stage1_phase2(void);
+void __attribute__((stdcall)) stage1_phase3(void);
+
/**
* This function is called from assembler code with its argument on the
* stack. Force the compiler to generate always correct code for this case.
@@ -154,29 +157,13 @@
* that we are restarting after some sort of reconfiguration. Note that we
could use it on geode but
* do not at present.
*/
-void __attribute__((stdcall)) stage1_main(u32 bist, u32 init_detected)
+void __attribute__((stdcall)) stage1_phase1(u32 bist, u32 init_detected)
{
struct global_vars globvars;
int ret;
struct mem_file archive;
- void *entry;
struct node_core_id me;
-#ifdef CONFIG_PAYLOAD_ELF_LOADER
- struct mem_file result;
- int elfboot_mem(struct lb_memory *mem, void *where, int size);
- /* Why can't we statically init this hack? */
- unsigned char faker[64];
- struct lb_memory *mem = (struct lb_memory*) faker;
-
- mem->tag = LB_TAG_MEMORY;
- mem->size = 28;
- mem->map[0].start.lo = mem->map[0].start.hi = 0;
- mem->map[0].size.lo = (32*1024*1024);
- mem->map[0].size.hi = 0;
- mem->map[0].type = LB_MEM_RAM;
-#endif /* CONFIG_PAYLOAD_ELF_LOADER */
-
post_code(POST_STAGE1_MAIN);
/* before we do anything, we want to stop if we do not run
@@ -234,6 +221,29 @@
printk(BIOS_DEBUG, "Done RAM init code\n");
+ /* Switch the stack location from CAR to RAM, rebuild the stack,
+ * disable CAR and continue at stage1_phase3(). This is all wrapped in
+ * stage1_phase2() to make the code easier to follow.
+ * We will NEVER return.
+ */
+ stage1_phase2();
+
+ /* If we reach this point, something went terribly wrong. */
+ die("The world is broken.\n");
+}
+
+/**
+ * This function is called to take care of switching and rebuilding the stack
+ * so that we can cope with processors which don't support a CAR area at low
+ * addresses where CAR could be copied to RAM without problems.
+ * After the stack has been rebuilt, we switch the stack pointer to the new
+ * location, move the printk buffer and cotinue at stage1_phase3().
+ *
+ * NOTE: switch_stack may need to be reimplemented in processor-specific asm.
+ * TODO: Reevaluate whether printk_buffer_move should come before disable_car()
+ */
+void stage1_phase2()
+{
/* Turn off Cache-As-Ram */
disable_car();
@@ -241,7 +251,37 @@
/* Move the printk buffer to PRINTK_BUF_ADDR_RAM */
printk_buffer_move((void *)PRINTK_BUF_ADDR_RAM, PRINTK_BUF_SIZE_RAM);
#endif
+ stage1_phase3();
+}
+/**
+ * This function is the second part of the former stage1_main() after
+ * switching the stack and disabling CAR.
+ */
+void __attribute__((stdcall)) stage1_phase3()
+{
+ void *entry;
+ int ret;
+ struct mem_file archive;
+#ifdef CONFIG_PAYLOAD_ELF_LOADER
+ struct mem_file result;
+ int elfboot_mem(struct lb_memory *mem, void *where, int size);
+
+ /* Why can't we statically init this hack? */
+ unsigned char faker[64];
+ struct lb_memory *mem = (struct lb_memory*) faker;
+
+ mem->tag = LB_TAG_MEMORY;
+ mem->size = 28;
+ mem->map[0].start.lo = mem->map[0].start.hi = 0;
+ mem->map[0].size.lo = (32*1024*1024);
+ mem->map[0].size.hi = 0;
+ mem->map[0].type = LB_MEM_RAM;
+#endif /* CONFIG_PAYLOAD_ELF_LOADER */
+
+ // location and size of image.
+ init_archive(&archive);
+
entry = load_file_segments(&archive, "normal/stage2");
if (entry == (void *)-1)
die("FATAL: Failed loading stage2.");
--
http://www.hailfinger.org/
--
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