Hi Simon,
On 14/12/12 17:48, Simon Glass wrote:
We currently assume that the global data pointer is at the start of struct global_data. We want to remove this restriction, and it is easiest to do this in C.
Remove the asm code and add equivalent code in C.
This idea was proposed by Graeme Russ here: http://patchwork.ozlabs.org/patch/199741/
Signed-off-by: Simon Glass sjg@chromium.org
Changes in v2:
- Add new patch to move gd pointer by C to asm on x86
arch/x86/cpu/cpu.c | 4 +++- arch/x86/cpu/start.S | 6 ------ 2 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c index 315e87a..6a23974 100644 --- a/arch/x86/cpu/cpu.c +++ b/arch/x86/cpu/cpu.c @@ -100,7 +100,9 @@ void setup_gdt(gd_t *id, u64 *gdt_addr) gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
/* FS: data, read/write, 4 GB, base (Global Data Pointer) */
- gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, (ulong)id, 0xfffff);
- id->arch.gd_addr = id;
- gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
(ulong)&id->arch.gd_addr, 0xfffff);
This patch needs to come before #12 as:
- gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, (ulong)id, 0xfffff); + id->gd_addr = id; + gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, + (ulong)&id->gd_addr, 0xfffff);
Then you can move gd_addr into arch-specific global data
Regards,
Graeme