diff options
| author | Simon Glass <sjg@chromium.org> | 2015-08-04 12:33:55 -0600 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2015-08-05 08:44:07 -0600 |
| commit | 6f92ed8f1abfe94ee1c96c83c21f4092bb04ff63 (patch) | |
| tree | f487163b3e28006dbe9023ae8c6c3abfbd211461 /arch/x86/include | |
| parent | 7dfe8bdeef7f8a7223fb39e04faaa5c7489feb3f (diff) | |
x86: Add a way to call 32-bit code from 64-bit mode
The procedure to drop from 64-bit mode to 32-bit is a bit messy. Add a
function to take care of it. It requires identity-mapped pages and that
the calling code is running below 4GB.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/cpu.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 5b891394fb..c70183ccef 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -230,6 +230,15 @@ char *cpu_get_name(char *name); void cpu_call64(ulong pgtable, ulong setup_base, ulong target); /** + * cpu_call32() - Jump to a 32-bit entry point + * + * @code_seg32: 32-bit code segment to use (GDT offset, e.g. 0x20) + * @target: Pointer to the start of the 32-bit U-Boot image/entry point + * @table: Pointer to start of info table to pass to U-Boot + */ +void cpu_call32(ulong code_seg32, ulong target, ulong table); + +/** * cpu_jump_to_64bit() - Jump to a 64-bit Linux kernel * * The kernel is uncompressed and the 64-bit entry point is expected to be |