On a VT100 terminal <ESC>[2J should be enough to both clear the whole screen and set the cursor to position (1, 1). But the Linux console does not behave like this. So send an extra <ESC>[H. For reference see the console_codes(4) man page.

Add a function description.

Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- lib/efi_loader/efi_console.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c index 218f7caa12..8494044799 100644 --- a/lib/efi_loader/efi_console.c +++ b/lib/efi_loader/efi_console.c @@ -360,12 +360,26 @@ static efi_status_t EFIAPI efi_cout_set_attribute( return EFI_EXIT(EFI_SUCCESS); }

+/** + * efi_cout_clear_screen() - clear screen + * + * This function implements the ClearScreen service of the + * EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL. See the Unified Extensible Firmware + * Interface (UEFI) specification for details. + * + * @this: pointer to the protocol instance + * Return: status code + */ static efi_status_t EFIAPI efi_cout_clear_screen( struct efi_simple_text_output_protocol *this) { EFI_ENTRY("%p", this);

- printf(ESC"[2J"); + /* + * The Linux console wants both a clear and a home command. The video + * uclass does not support <ESC>[H without coordinates, yet. + */ + printf(ESC "[2J" ESC "[1;1H"); efi_con_mode.cursor_column = 0; efi_con_mode.cursor_row = 0;

-- 2.20.1