From: Ard Biesheuvel <ardb@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>, Geert Uytterhoeven <geert+renesas@glider.be>, Nicolas Pitre <nico@fluxnic.net>, Linus Walleij <linus.walleij@linaro.org>, Russell King <linux@armlinux.org.uk> Subject: [PATCH 3/5] ARM: decompressor: defer loading of the contents of the LC0 structure Date: Fri, 27 Mar 2020 11:59:04 +0100 [thread overview] Message-ID: <20200327105906.2665-4-ardb@kernel.org> (raw) In-Reply-To: <20200327105906.2665-1-ardb@kernel.org> The remaining contents of LC0 are only used after the point in the decompressor startup code where we enter via 'wont_overwrite'. So move the loading of the LC0 structure after it. This will allow us to jump to wont_overwrite directly from the EFI stub, and execute the decompressor in place at the offset it was loaded by the UEFI firmware. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/boot/compressed/head.S | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index a6cf2f8115e5..35d4db00eaf9 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -347,10 +347,6 @@ restart: adr r0, LC1 add sp, r1, r0 add r6, r6, r0 - adr r0, LC0 - ldmia r0, {r1, r2, r3, r11, r12} - sub r0, r0, r1 @ calculate the delta offset - get_inflated_image_size r9, r10, lr #ifndef CONFIG_ZBOOT_ROM @@ -368,9 +364,6 @@ restart: adr r0, LC1 mov r5, #0 @ init dtb size to 0 #ifdef CONFIG_ARM_APPENDED_DTB /* - * r0 = delta - * r2 = BSS start - * r3 = BSS end * r4 = final kernel address (possibly with LSB set) * r5 = appended dtb size (still unknown) * r6 = _edata @@ -378,8 +371,6 @@ restart: adr r0, LC1 * r8 = atags/device tree pointer * r9 = size of decompressed image * r10 = end of this image, including bss/stack/malloc space if non XIP - * r11 = GOT start - * r12 = GOT end * sp = stack pointer * * if there are device trees (dtb) appended to zImage, advance r10 so that the @@ -427,7 +418,6 @@ restart: adr r0, LC1 /* temporarily relocate the stack past the DTB work space */ add sp, sp, r5 - stmfd sp!, {r0-r3, ip, lr} mov r0, r8 mov r1, r6 mov r2, r5 @@ -446,7 +436,6 @@ restart: adr r0, LC1 mov r2, r5 bleq atags_to_fdt - ldmfd sp!, {r0-r3, ip, lr} sub sp, sp, r5 #endif @@ -583,6 +572,10 @@ dtb_check_done: mov pc, r0 wont_overwrite: + adr r0, LC0 + ldmia r0, {r1, r2, r3, r11, r12} + sub r0, r0, r1 @ calculate the delta offset + /* * If delta is zero, we are running at the address we were linked at. * r0 = delta -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org, Geert Uytterhoeven <geert+renesas@glider.be>, Nicolas Pitre <nico@fluxnic.net>, Linus Walleij <linus.walleij@linaro.org>, Russell King <linux@armlinux.org.uk>, Ard Biesheuvel <ardb@kernel.org> Subject: [PATCH 3/5] ARM: decompressor: defer loading of the contents of the LC0 structure Date: Fri, 27 Mar 2020 11:59:04 +0100 [thread overview] Message-ID: <20200327105906.2665-4-ardb@kernel.org> (raw) In-Reply-To: <20200327105906.2665-1-ardb@kernel.org> The remaining contents of LC0 are only used after the point in the decompressor startup code where we enter via 'wont_overwrite'. So move the loading of the LC0 structure after it. This will allow us to jump to wont_overwrite directly from the EFI stub, and execute the decompressor in place at the offset it was loaded by the UEFI firmware. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/boot/compressed/head.S | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index a6cf2f8115e5..35d4db00eaf9 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -347,10 +347,6 @@ restart: adr r0, LC1 add sp, r1, r0 add r6, r6, r0 - adr r0, LC0 - ldmia r0, {r1, r2, r3, r11, r12} - sub r0, r0, r1 @ calculate the delta offset - get_inflated_image_size r9, r10, lr #ifndef CONFIG_ZBOOT_ROM @@ -368,9 +364,6 @@ restart: adr r0, LC1 mov r5, #0 @ init dtb size to 0 #ifdef CONFIG_ARM_APPENDED_DTB /* - * r0 = delta - * r2 = BSS start - * r3 = BSS end * r4 = final kernel address (possibly with LSB set) * r5 = appended dtb size (still unknown) * r6 = _edata @@ -378,8 +371,6 @@ restart: adr r0, LC1 * r8 = atags/device tree pointer * r9 = size of decompressed image * r10 = end of this image, including bss/stack/malloc space if non XIP - * r11 = GOT start - * r12 = GOT end * sp = stack pointer * * if there are device trees (dtb) appended to zImage, advance r10 so that the @@ -427,7 +418,6 @@ restart: adr r0, LC1 /* temporarily relocate the stack past the DTB work space */ add sp, sp, r5 - stmfd sp!, {r0-r3, ip, lr} mov r0, r8 mov r1, r6 mov r2, r5 @@ -446,7 +436,6 @@ restart: adr r0, LC1 mov r2, r5 bleq atags_to_fdt - ldmfd sp!, {r0-r3, ip, lr} sub sp, sp, r5 #endif @@ -583,6 +572,10 @@ dtb_check_done: mov pc, r0 wont_overwrite: + adr r0, LC0 + ldmia r0, {r1, r2, r3, r11, r12} + sub r0, r0, r1 @ calculate the delta offset + /* * If delta is zero, we are running at the address we were linked at. * r0 = delta -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-03-27 10:59 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-27 10:59 [PATCH 0/5] ARM: simplify handover from UEFI to decompressor Ard Biesheuvel 2020-03-27 10:59 ` Ard Biesheuvel 2020-03-27 10:59 ` [PATCH 1/5] ARM: decompressor: move headroom variable out of LC0 Ard Biesheuvel 2020-03-27 10:59 ` Ard Biesheuvel 2020-03-27 13:23 ` Geert Uytterhoeven 2020-03-27 13:23 ` Geert Uytterhoeven 2020-03-27 13:59 ` Ard Biesheuvel 2020-03-27 13:59 ` Ard Biesheuvel 2020-03-27 10:59 ` [PATCH 2/5] ARM: decompressor: split off _edata and stack base into separate object Ard Biesheuvel 2020-03-27 10:59 ` Ard Biesheuvel 2020-03-27 13:23 ` Geert Uytterhoeven 2020-03-27 13:23 ` Geert Uytterhoeven 2020-03-27 10:59 ` Ard Biesheuvel [this message] 2020-03-27 10:59 ` [PATCH 3/5] ARM: decompressor: defer loading of the contents of the LC0 structure Ard Biesheuvel 2020-03-27 13:24 ` Geert Uytterhoeven 2020-03-27 13:24 ` Geert Uytterhoeven 2020-03-27 10:59 ` [PATCH 4/5] ARM: decompressor: move GOT into .data for EFI enabled builds Ard Biesheuvel 2020-03-27 10:59 ` Ard Biesheuvel 2020-03-27 10:59 ` [PATCH 5/5] ARM: decompressor: run decompressor in place if loaded via UEFI Ard Biesheuvel 2020-03-27 10:59 ` Ard Biesheuvel
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