mk-rootfs.sh

hc

2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376

 kernel/arch/arm64/kernel/efi-entry.S
..
..
@@ -1,94 +1,44 @@
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+/* SPDX-License-Identifier: GPL-2.0-only */
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 /*
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  * EFI entry point.
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  *
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  * Copyright (C) 2013, 2014 Red Hat, Inc.
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  * Author: Mark Salter <msalter@redhat.com>
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- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2 as
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- * published by the Free Software Foundation.
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- *
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  */
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 #include <linux/linkage.h>
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 #include <linux/init.h>
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 #include <asm/assembler.h>
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-#define EFI_LOAD_ERROR 0x8000000000000001
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-
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 	__INIT
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14
 
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+SYM_CODE_START(efi_enter_kernel)
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 	/*
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-	 * We arrive here from the EFI boot manager with:
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-	 *
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-	 *    * CPU in little-endian mode
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-	 *    * MMU on with identity-mapped RAM
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-	 *    * Icache and Dcache on
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-	 *
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-	 * We will most likely be running from some place other than where
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-	 * we want to be. The kernel image wants to be placed at TEXT_OFFSET
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-	 * from start of RAM.
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+	 * efi_pe_entry() will have copied the kernel image if necessary and we
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+	 * end up here with device tree address in x1 and the kernel entry
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+	 * point stored in x0. Save those values in registers which are
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+	 * callee preserved.
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 	 */
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-ENTRY(entry)
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-	/*
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-	 * Create a stack frame to save FP/LR with extra space
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-	 * for image_addr variable passed to efi_entry().
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-	 */
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-	stp	x29, x30, [sp, #-32]!
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-	mov	x29, sp
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+	ldr	w2, =primary_entry_offset
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+	add	x19, x0, x2		// relocated Image entrypoint
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+	mov	x20, x1			// DTB address
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 	/*
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-	 * Call efi_entry to do the real work.
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-	 * x0 and x1 are already set up by firmware. Current runtime
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-	 * address of image is calculated and passed via *image_addr.
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-	 *
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-	 * unsigned long efi_entry(void *handle,
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-	 *                         efi_system_table_t *sys_table,
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-	 *                         unsigned long *image_addr) ;
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-	 */
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-	adr_l	x8, _text
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-	add	x2, sp, 16
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-	str	x8, [x2]
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-	bl	efi_entry
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-	cmn	x0, #1
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-	b.eq	efi_load_fail
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-
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-	/*
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-	 * efi_entry() will have copied the kernel image if necessary and we
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-	 * return here with device tree address in x0 and the kernel entry
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-	 * point stored at *image_addr. Save those values in registers which
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-	 * are callee preserved.
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-	 */
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-	mov	x20, x0		// DTB address
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-	ldr	x0, [sp, #16]	// relocated _text address
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-	ldr	w21, =stext_offset
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-	add	x21, x0, x21
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-
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-	/*
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-	 * Calculate size of the kernel Image (same for original and copy).
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-	 */
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-	adr_l	x1, _text
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-	adr_l	x2, _edata
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-	sub	x1, x2, x1
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-
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-	/*
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-	 * Flush the copied Image to the PoC, and ensure it is not shadowed by
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+	 * Clean the copied Image to the PoC, and ensure it is not shadowed by
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 	 * stale icache entries from before relocation.
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 	 */
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-	bl	__flush_dcache_area
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+	ldr	w1, =kernel_size
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+	bl	__clean_dcache_area_poc
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 	ic	ialluis
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 	/*
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-	 * Ensure that the rest of this function (in the original Image) is
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-	 * visible when the caches are disabled. The I-cache can't have stale
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-	 * entries for the VA range of the current image, so no maintenance is
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-	 * necessary.
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+	 * Clean the remainder of this routine to the PoC
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+	 * so that we can safely disable the MMU and caches.
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 	 */
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-	adr	x0, entry
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-	adr	x1, entry_end
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-	sub	x1, x1, x0
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-	bl	__flush_dcache_area
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-
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+	adr	x0, 0f
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+	ldr	w1, 3f
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+	bl	__clean_dcache_area_poc
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+0:
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 	/* Turn off Dcache and MMU */
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 	mrs	x0, CurrentEL
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 	cmp	x0, #CurrentEL_EL2
..
..
@@ -113,12 +63,6 @@
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 	mov	x1, xzr
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 	mov	x2, xzr
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 	mov	x3, xzr
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-	br	x21
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-
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-efi_load_fail:
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-	mov	x0, #EFI_LOAD_ERROR
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-	ldp	x29, x30, [sp], #32
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-	ret
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-
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-entry_end:
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-ENDPROC(entry)
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+	br	x19
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+SYM_CODE_END(efi_enter_kernel)
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+3:	.long	. - 0b