ARM: decompressor: run decompressor in place if loaded via UEFI (d0f9ca9b) · Commits · 戴 / test

arch/arm/boot/compressed/head.S

+14 −25

Original line number	Diff line number	Diff line
		@@ -1430,37 +1430,26 @@ reloc_code_end:

		#ifdef CONFIG_EFI_STUB
		ENTRY(efi_enter_kernel)
		mov r7, r0 @ preserve image base
		mov r4, r1 @ preserve DT pointer
		mov r4, r0 @ preserve image base
		mov r8, r1 @ preserve DT pointer

		mov r0, r4 @ DT start
		add r1, r4, r2 @ DT end
		bl cache_clean_flush
		mrc p15, 0, r0, c1, c0, 0 @ read SCTLR
		tst r0, #0x1 @ MMU enabled?
		orreq r4, r4, #1 @ set LSB if not

		mov r0, r7 @ relocated zImage
		ldr r1, =_edata @ size of zImage
		add r1, r1, r0 @ end of zImage
		mov r0, r8 @ DT start
		add r1, r8, r2 @ DT end
		bl cache_clean_flush

		@ The PE/COFF loader might not have cleaned the code we are
		@ running beyond the PoU, and so calling cache_off below from
		@ inside the PE/COFF loader allocated region is unsafe unless
		@ we explicitly clean it to the PoC.
		adr r0, call_cache_fn @ region of code we will
		adr r1, 0f @ run with MMU off
		bl cache_clean_flush
		bl cache_off
		adr r0, 0f @ switch to our stack
		ldr sp, [r0]
		add sp, sp, r0

		@ Set parameters for booting zImage according to boot protocol
		@ put FDT address in r2, it was returned by efi_entry()
		@ r1 is the machine type, and r0 needs to be 0
		mov r0, #0
		mov r1, #0xFFFFFFFF
		mov r2, r4
		add r7, r7, #(__efi_start - start)
		mov pc, r7 @ no mode switch
		mov r5, #0 @ appended DTB size
		mov r7, #0xFFFFFFFF @ machine ID
		b wont_overwrite
		ENDPROC(efi_enter_kernel)
		0:
		0: .long .L_user_stack_end - .
		#endif

		.align

drivers/firmware/efi/libstub/arm32-stub.c

+6 −39

Original line number	Diff line number	Diff line
		@@ -199,14 +199,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
		unsigned long kernel_base;
		efi_status_t status;

		/*
		* Verify that the DRAM base address is compatible with the ARM
		* boot protocol, which determines the base of DRAM by masking
		* off the low 27 bits of the address at which the zImage is
		* loaded. These assumptions are made by the decompressor,
		* before any memory map is available.
		*/
		kernel_base = round_up(dram_base, SZ_128M);
		/* use a 16 MiB aligned base for the decompressed kernel */
		kernel_base = round_up(dram_base, SZ_16M) + TEXT_OFFSET;

		/*
		* Note that some platforms (notably, the Raspberry Pi 2) put
		@@ -215,41 +209,14 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
		* base of the kernel image is only partially used at the moment.
		* (Up to 5 pages are used for the swapper page tables)
		*/
		kernel_base += TEXT_OFFSET - 5 * PAGE_SIZE;

		status = reserve_kernel_base(kernel_base, reserve_addr, reserve_size);
		status = reserve_kernel_base(kernel_base - 5 * PAGE_SIZE, reserve_addr,
		reserve_size);
		if (status != EFI_SUCCESS) {
		pr_efi_err("Unable to allocate memory for uncompressed kernel.\n");
		return status;
		}

		/*
		* Relocate the zImage, so that it appears in the lowest 128 MB
		* memory window.
		*/
		*image_addr = (unsigned long)image->image_base;
		*image_size = image->image_size;
		status = efi_relocate_kernel(image_addr, image_size, image_size,
		kernel_base + MAX_UNCOMP_KERNEL_SIZE, 0, 0);
		if (status != EFI_SUCCESS) {
		pr_efi_err("Failed to relocate kernel.\n");
		efi_free(reserve_size, reserve_addr);
		*reserve_size = 0;
		return status;
		}

		/*
		* Check to see if we were able to allocate memory low enough
		* in memory. The kernel determines the base of DRAM from the
		* address at which the zImage is loaded.
		*/
		if (image_addr + image_size > dram_base + ZIMAGE_OFFSET_LIMIT) {
		pr_efi_err("Failed to relocate kernel, no low memory available.\n");
		efi_free(reserve_size, reserve_addr);
		*reserve_size = 0;
		efi_free(image_size, image_addr);
		*image_addr = kernel_base;
		*image_size = 0;
		return EFI_LOAD_ERROR;
		}
		return EFI_SUCCESS;
		}

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