Messages in this thread Patch in this message | | | Date | Sun, 13 Jul 2008 21:18:02 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [RFT] x86 acpi: normalize segment descriptor register on resume |
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H. Peter Anvin wrote: > > The most likely explanation for this is that the VESA BIOS expects to be > entered in Big Real Mode (*.limit = 0xffffffff) instead of ordinary Real > Mode. Here is a completely untested patch which changes the segment > descriptors to Big Real Mode instead. It would be worth testing out. >
... and here is one that actually has a prayer of actually working.
-hpa diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 36af01f..130711f 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -23,6 +23,15 @@ static unsigned long acpi_realmode; static char temp_stack[10240]; #endif +/* XXX: this macro should move to asm-x86/segment.h and be shared with the + boot code... */ +#define GDT_ENTRY(flags, base, limit) \ + (((u64)(base & 0xff000000) << 32) | \ + ((u64)flags << 40) | \ + ((u64)(limit & 0x00ff0000) << 32) | \ + ((u64)(base & 0x00ffffff) << 16) | \ + ((u64)(limit & 0x0000ffff))) + /** * acpi_save_state_mem - save kernel state * @@ -58,11 +67,11 @@ int acpi_save_state_mem(void) ((char *)&header->wakeup_gdt - (char *)acpi_realmode)) << 16); /* GDT[1]: real-mode-like code segment */ - header->wakeup_gdt[1] = (0x009bULL << 40) + - ((u64)acpi_wakeup_address << 16) + 0xffff; + header->wakeup_gdt[1] = + GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff); /* GDT[2]: real-mode-like data segment */ - header->wakeup_gdt[2] = (0x0093ULL << 40) + - ((u64)acpi_wakeup_address << 16) + 0xffff; + header->wakeup_gdt[2] = + GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff); #ifndef CONFIG_64BIT store_gdt((struct desc_ptr *)&header->pmode_gdt); | |