[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH v2 3/7] x86/boot: Only jump into low trampoline code for real-mode boot
From: David Woodhouse <dwmw@xxxxxxxxxxxx> If the no-real-mode flag is set, don't go there at all. This is a prelude to not even putting it there in the first place. Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx> --- xen/arch/x86/boot/head.S | 10 ++++++++++ xen/arch/x86/boot/trampoline.S | 4 ---- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index db19ac6fd8..7c30de3671 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -734,7 +734,17 @@ trampoline_setup: /* Switch to low-memory stack which lives at the end of trampoline region. */ mov sym_fs(trampoline_phys),%edi lea TRAMPOLINE_SPACE+TRAMPOLINE_STACK_SPACE(%edi),%esp + cmpb $0, sym_fs(skip_realmode) + jz 1f + /* If no-real-mode, jump straight to trampoline_protmode_entry */ + lea trampoline_protmode_entry-trampoline_start(%edi),%eax + /* EBX == 0 indicates we are the BP (Boot Processor). */ + xor %ebx,%ebx + jmp 2f +1: + /* Go via 16-bit code in trampoline_boot_cpu_entry */ lea trampoline_boot_cpu_entry-trampoline_start(%edi),%eax +2: pushl $BOOT_CS32 push %eax diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S index 5588c7986a..df0ffd5013 100644 --- a/xen/arch/x86/boot/trampoline.S +++ b/xen/arch/x86/boot/trampoline.S @@ -187,9 +187,6 @@ start64: .code32 trampoline_boot_cpu_entry: - cmpb $0,bootsym_rel(skip_realmode,5) - jnz .Lskip_realmode - /* Load pseudo-real-mode segments. */ mov $BOOT_PSEUDORM_DS,%eax mov %eax,%ds @@ -269,7 +266,6 @@ trampoline_boot_cpu_entry: mov %eax,%gs mov %eax,%ss -.Lskip_realmode: /* EBX == 0 indicates we are the BP (Boot Processor). */ xor %ebx,%ebx -- 2.17.2 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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