diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2013-02-08 16:56:51 -0600 |
|---|---|---|
| committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2013-03-21 18:01:38 +0100 |
| commit | a146d58ca0375a12f23dc5a4bd25adfa3423114f (patch) | |
| tree | 874776d78835bf56ba66eba54e2558edd97645de /src/cpu/x86/lapic | |
| parent | e8c866ad45d80de768c9422474449e171d133575 (diff) | |
ramstage: prepare for relocation
The current ramstage code contains uses of symbols that cause issues
when the ramstage is relocatable. There are 2 scenarios resolved by this
patch:
1. Absolute symbols that are actually sizes/limits. The symbols are
problematic when relocating a program because there is no way to
distinguish a symbol that shouldn't be relocated and one that can.
The only way to handle these symbols is to write a program to post
process the relocations and keep a whitelist of ones that shouldn't
be relocated. I don't believe that is a route that should be taken
so fix the users of these sizes/limits encoded as absolute symbols
to calculate the size at runtime or dereference a variable in memory
containing the size/limit.
2. Absoulte symbols that were relocated to a fixed address. These
absolute symbols are generated by assembly files to be placed at a
fixed location. Again, these symbols are problematic because one
can't distinguish a symbol that can't be relocated. The symbols
are again resolved at runtime to allow for proper relocation.
For the symbols defining a size either use 2 symbols and calculate the
difference or provide a variable in memory containing the size.
Change-Id: I1ef2bfe6fd531308218bcaac5dcccabf8edf932c
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2789
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
Diffstat (limited to 'src/cpu/x86/lapic')
| -rw-r--r-- | src/cpu/x86/lapic/lapic_cpu_init.c | 18 | ||||
| -rw-r--r-- | src/cpu/x86/lapic/secondary.S | 8 |
2 files changed, 23 insertions, 3 deletions
diff --git a/src/cpu/x86/lapic/lapic_cpu_init.c b/src/cpu/x86/lapic/lapic_cpu_init.c index 9a00b8289f..69430d551f 100644 --- a/src/cpu/x86/lapic/lapic_cpu_init.c +++ b/src/cpu/x86/lapic/lapic_cpu_init.c @@ -52,12 +52,30 @@ int lowmem_backup_size; #endif extern char _secondary_start[]; +extern char _secondary_gdt_addr[]; +extern char gdt[]; +extern char gdt_end[]; + +static inline void setup_secondary_gdt(void) +{ + u16 *gdt_limit; + u32 *gdt_base; + + gdt_limit = (void *)&_secondary_gdt_addr; + gdt_base = (void *)&gdt_limit[1]; + + *gdt_limit = (u32)&gdt_end - (u32)&gdt - 1; + *gdt_base = (u32)&gdt; +} static void copy_secondary_start_to_lowest_1M(void) { extern char _secondary_start_end[]; unsigned long code_size; + /* Fill in secondary_start's local gdt. */ + setup_secondary_gdt(); + code_size = (unsigned long)_secondary_start_end - (unsigned long)_secondary_start; #if CONFIG_HAVE_ACPI_RESUME diff --git a/src/cpu/x86/lapic/secondary.S b/src/cpu/x86/lapic/secondary.S index 2e0620e2da..6edcd0a366 100644 --- a/src/cpu/x86/lapic/secondary.S +++ b/src/cpu/x86/lapic/secondary.S @@ -3,7 +3,7 @@ #if CONFIG_SMP && CONFIG_MAX_CPUS > 1 .text - .globl _secondary_start, _secondary_start_end + .globl _secondary_start, _secondary_start_end, _secondary_gdt_addr .balign 4096 _secondary_start: .code16 @@ -28,9 +28,11 @@ _secondary_start: ljmpl $0x10, $__ap_protected_start + /* This will get filled in by C code. */ +_secondary_gdt_addr: gdtaddr: - .word gdt_limit /* the table limit */ - .long gdt /* we know the offset */ + .word 0 /* the table limit */ + .long 0 /* we know the offset */ _secondary_start_end: |