efi/gop: Allow specifying mode number on command line (fffb6804) · Commits · 戴 / test

Documentation/fb/efifb.rst

+17 −3

Original line number	Diff line number	Diff line
		@@ -2,8 +2,10 @@
		What is efifb?
		==============

		This is a generic EFI platform driver for Intel based Apple computers.
		efifb is only for EFI booted Intel Macs.
		This is a generic EFI platform driver for systems with UEFI firmware. The
		system must be booted via the EFI stub for this to be usable. efifb supports
		both firmware with Graphics Output Protocol (GOP) displays as well as older
		systems with only Universal Graphics Adapter (UGA) displays.

		Supported Hardware
		==================
		@@ -12,11 +14,14 @@ Supported Hardware
		- Macbook
		- Macbook Pro 15"/17"
		- MacMini
		- ARM/ARM64/X86 systems with UEFI firmware

		How to use it?
		==============

		efifb does not have any kind of autodetection of your machine.
		For UGA displays, efifb does not have any kind of autodetection of your
		machine.

		You have to add the following kernel parameters in your elilo.conf::

		Macbook :
		@@ -28,6 +33,9 @@ You have to add the following kernel parameters in your elilo.conf::
		Macbook Pro 17", iMac 20" :
		video=efifb:i20

		For GOP displays, efifb can autodetect the display's resolution and framebuffer
		address, so these should work out of the box without any special parameters.

		Accepted options:

		======= ===========================================================
		@@ -36,4 +44,10 @@ nowc Don't map the framebuffer write combined. This can be used
		when large amounts of console data are written.
		======= ===========================================================

		Options for GOP displays:

		mode=n
		The EFI stub will set the mode of the display to mode number n if
		possible.

		Edgar Hucek <gimli@dark-green.com>

drivers/firmware/efi/libstub/efi-stub-helper.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -105,6 +105,9 @@ efi_status_t efi_parse_options(char const *cmdline)
		efi_disable_pci_dma = true;
		if (parse_option_str(val, "no_disable_early_pci_dma"))
		efi_disable_pci_dma = false;
		} else if (!strcmp(param, "video") &&
		val && strstarts(val, "efifb:")) {
		efi_parse_option_graphics(val + strlen("efifb:"));
		}
		}
		efi_bs_call(free_pool, buf);

drivers/firmware/efi/libstub/efistub.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -666,6 +666,8 @@ efi_status_t efi_relocate_kernel(unsigned long *image_addr,

		efi_status_t efi_parse_options(char const *cmdline);

		void efi_parse_option_graphics(char *option);

		efi_status_t efi_setup_gop(struct screen_info si, efi_guid_t proto,
		unsigned long size);

drivers/firmware/efi/libstub/gop.c

+107 −0

Original line number	Diff line number	Diff line
		@@ -8,11 +8,115 @@
		#include <linux/bitops.h>
		#include <linux/efi.h>
		#include <linux/screen_info.h>
		#include <linux/string.h>
		#include <asm/efi.h>
		#include <asm/setup.h>

		#include "efistub.h"

		enum efi_cmdline_option {
		EFI_CMDLINE_NONE,
		EFI_CMDLINE_MODE_NUM,
		};

		static struct {
		enum efi_cmdline_option option;
		u32 mode;
		} cmdline __efistub_global = { .option = EFI_CMDLINE_NONE };

		static bool parse_modenum(char option, char *next)
		{
		u32 m;

		if (!strstarts(option, "mode="))
		return false;
		option += strlen("mode=");
		m = simple_strtoull(option, &option, 0);
		if (option && option++ != ',')
		return false;
		cmdline.option = EFI_CMDLINE_MODE_NUM;
		cmdline.mode = m;

		*next = option;
		return true;
		}

		void efi_parse_option_graphics(char *option)
		{
		while (*option) {
		if (parse_modenum(option, &option))
		continue;

		while (option && option++ != ',')
		;
		}
		}

		static u32 choose_mode_modenum(efi_graphics_output_protocol_t *gop)
		{
		efi_status_t status;

		efi_graphics_output_protocol_mode_t *mode;
		efi_graphics_output_mode_info_t *info;
		unsigned long info_size;

		u32 max_mode, cur_mode;
		int pf;

		mode = efi_table_attr(gop, mode);

		cur_mode = efi_table_attr(mode, mode);
		if (cmdline.mode == cur_mode)
		return cur_mode;

		max_mode = efi_table_attr(mode, max_mode);
		if (cmdline.mode >= max_mode) {
		efi_printk("Requested mode is invalid\n");
		return cur_mode;
		}

		status = efi_call_proto(gop, query_mode, cmdline.mode,
		&info_size, &info);
		if (status != EFI_SUCCESS) {
		efi_printk("Couldn't get mode information\n");
		return cur_mode;
		}

		pf = info->pixel_format;

		efi_bs_call(free_pool, info);

		if (pf == PIXEL_BLT_ONLY \|\| pf >= PIXEL_FORMAT_MAX) {
		efi_printk("Invalid PixelFormat\n");
		return cur_mode;
		}

		return cmdline.mode;
		}

		static void set_mode(efi_graphics_output_protocol_t *gop)
		{
		efi_graphics_output_protocol_mode_t *mode;
		u32 cur_mode, new_mode;

		switch (cmdline.option) {
		case EFI_CMDLINE_MODE_NUM:
		new_mode = choose_mode_modenum(gop);
		break;
		default:
		return;
		}

		mode = efi_table_attr(gop, mode);
		cur_mode = efi_table_attr(mode, mode);

		if (new_mode == cur_mode)
		return;

		if (efi_call_proto(gop, set_mode, new_mode) != EFI_SUCCESS)
		efi_printk("Failed to set requested mode\n");
		}

		static void find_bits(u32 mask, u8 pos, u8 size)
		{
		if (!mask) {
		@@ -124,6 +228,9 @@ static efi_status_t setup_gop(struct screen_info si, efi_guid_t proto,
		if (!gop)
		return EFI_NOT_FOUND;

		/* Change mode if requested */
		set_mode(gop);

		/* EFI framebuffer */
		mode = efi_table_attr(gop, mode);
		info = efi_table_attr(mode, info);

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