diff options
| author | Simon Glass <[email protected]> | 2025-03-15 14:25:37 +0000 |
|---|---|---|
| committer | Tom Rini <[email protected]> | 2025-04-03 11:41:55 -0600 |
| commit | f5f1ed8ae7395dbffa611823457a3beeda462577 (patch) | |
| tree | 00f50864f99f2334f021f1b38553c9cfcb721a9b | |
| parent | 3c7ab12249a986267f0eb60dffaa85c1f254148e (diff) | |
x86: Disable paging before changing to long mode
This is required as part of the procedure. The existing code works
because it changes the GDT at the same time, but this makes kvm
unhappy.
Update the algorithm to disable and then re-enable paging.
Signed-off-by: Simon Glass <[email protected]>
| -rw-r--r-- | arch/x86/cpu/i386/call64.S | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/cpu/i386/call64.S b/arch/x86/cpu/i386/call64.S index 424732fa3fa..f979f9e5f0e 100644 --- a/arch/x86/cpu/i386/call64.S +++ b/arch/x86/cpu/i386/call64.S @@ -25,6 +25,11 @@ cpu_call64: push %edx /* arg1 = setup_base */ mov %eax, %ebx + # disable paging + movl %cr0, %eax + andl $~X86_CR0_PG, %eax + movl %eax, %cr0 + /* Load new GDT with the 64bit segments using 32bit descriptor */ leal gdt, %eax movl %eax, gdt+2 @@ -67,7 +72,8 @@ cpu_call64: pushl %eax /* Enter paged protected Mode, activating Long Mode */ - movl $(X86_CR0_PG | X86_CR0_PE), %eax + movl %cr0, %eax + orl $X86_CR0_PG, %eax movl %eax, %cr0 /* Jump from 32bit compatibility mode into 64bit mode. */ |