On Thu, Mar 13, 2014 at 10:47:04PM +0000, Leif Lindholm wrote: > --- /dev/null > +++ b/arch/arm64/kernel/efi-entry.S > @@ -0,0 +1,93 @@ > +/* > + * EFI entry point. > + * > + * Copyright (C) 2013 Red Hat, Inc. > + * Author: Mark Salter <msalter@xxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + */ > +#include <linux/linkage.h> > +#include <linux/init.h> > + > +#include <asm/assembler.h> > + > +#define EFI_LOAD_ERROR 0x8000000000000001 > + > + __INIT > + > + /* > + * We arrive here from the EFI boot manager with: > + * > + * * MMU on with identity-mapped RAM. > + * * Icache and Dcache on > + * > + * We will most likely be running from some place other than where > + * we want to be. The kernel image wants to be placed at TEXT_OFFSET > + * from start of RAM. > + */ > +ENTRY(efi_stub_entry) > + stp x29, x30, [sp, #-32]! > + > + /* > + * Call efi_entry to do the real work. > + * x0 and x1 are already set up by firmware. Current runtime > + * address of image is calculated and passed via *image_addr. > + * > + * unsigned long efi_entry(void *handle, > + * efi_system_table_t *sys_table, > + * unsigned long *image_addr) ; > + */ > + adrp x8, _text > + add x8, x8, #:lo12:_text > + add x2, sp, 16 > + str x8, [x2] > + bl efi_entry > + cmn x0, #1 > + b.eq efi_load_fail > + > + /* > + * efi_entry() will have relocated the kernel image if necessary > + * and we return here with device tree address in x0 and the kernel > + * entry point stored at *image_addr. Save those values in registers > + * which are preserved by __flush_dcache_all. > + */ > + ldr x1, [sp, #16] > + mov x20, x0 > + mov x21, x1 > + > + /* Turn off Dcache and MMU */ > + mrs x0, CurrentEL > + cmp x0, #PSR_MODE_EL2t > + ccmp x0, #PSR_MODE_EL2h, #0x4, ne > + b.ne 1f > + mrs x0, sctlr_el2 > + bic x0, x0, #1 << 0 // clear SCTLR.M > + bic x0, x0, #1 << 2 // clear SCTLR.C > + msr sctlr_el2, x0 > + isb > + b 2f > +1: > + mrs x0, sctlr_el1 > + bic x0, x0, #1 << 0 // clear SCTLR.M > + bic x0, x0, #1 << 2 // clear SCTLR.C > + msr sctlr_el1, x0 > + isb > +2: > + bl __flush_dcache_all In linux-next I'm pushing a patch which no longer exports the __flush_dcache_all function. The reason is that it doesn't really work if you have a (not fully transparent) external cache like on the Applied Micro boards. There other issues when running as a guest as well. If you know exactly what needs to be flushed here, can you use a range (MVA) operation? > diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c > new file mode 100644 > index 0000000..bf30913 > --- /dev/null > +++ b/arch/arm64/kernel/efi-stub.c > @@ -0,0 +1,83 @@ > +/* > + * linux/arch/arm/boot/compressed/efi-stub.c Nitpick: arch/arm64/... But we don't really need to write the file name here, I use a smart editor that tells me which file I'm viewing ;). Better write a one-line summary of what this file is about. > + * > + * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@xxxxxxxxxx> > + * > + * This file implements the EFI boot stub for the arm64 kernel. > + * Adapted from ARM version by Mark Salter <msalter@xxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + */ > +#include <linux/efi.h> > +#include <linux/libfdt.h> > +#include <asm/sections.h> > +#include <generated/compile.h> > +#include <generated/utsrelease.h> > + > +/* > + * EFI function call wrappers. These are not required for arm/arm64, but > + * wrappers are required for X86 to convert between ABIs. These wrappers are > + * provided to allow code sharing between X86 and other architectures. Since > + * these wrappers directly invoke the EFI function pointer, the function > + * pointer type must be properly defined, which is not the case for X86. One > + * advantage of this is it allows for type checking of arguments, which is not > + * possible with the X86 wrappers. > + */ > +#define efi_call_phys0(f) f() > +#define efi_call_phys1(f, a1) f(a1) > +#define efi_call_phys2(f, a1, a2) f(a1, a2) > +#define efi_call_phys3(f, a1, a2, a3) f(a1, a2, a3) > +#define efi_call_phys4(f, a1, a2, a3, a4) f(a1, a2, a3, a4) > +#define efi_call_phys5(f, a1, a2, a3, a4, a5) f(a1, a2, a3, a4, a5) > + > +/* > + * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from > + * start of kernel and may not cross a 2MiB boundary. We set alignment to > + * 2MiB so we know it won't cross a 2MiB boundary. > + */ > +#define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */ > +#define MAX_FDT_OFFSET SZ_512M > + > +/* Include shared EFI stub code */ > +#include "../../../drivers/firmware/efi/efi-stub-helper.c" It looks like this is done by x86 as well. > +#include "../../../drivers/firmware/efi/fdt.c" > +#include "../../../drivers/firmware/efi/arm-stub.c" But why do we need to create more stuff like this? Is it because on arm we need this as part of the decompressor (which would be a good enough argument)? -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
