sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ArmVirtPkg/XenRelocatablePlatformLib: rewrite DTB memory node retrieval in C

Browse Source 
Parsing the DTB early on using a handcoded assembly routine is a pointless
waste of brain cycles, since the UEFI firmware always executes from RAM
under Xen. So instead, set up a temporary stack in the memory region at the
beginning of the image, and use the libfdt C library.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19330 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Ard Biesheuvel
2015-12-17 17:11:07 +00:00
committed by abiesheuvel
parent ce44ee32d3
commit 03b6bed17e
4 changed files with 113 additions and 269 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
ArmVirtPkg/Library/ArmXenRelocatablePlatformLib/AARCH64/RelocatableVirtHelper.S
View File

@@ -30,9 +30,6 @@ GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdArmPrimaryCore)
GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdArmPrimaryCoreMask)
GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdCoreCount)
.LFdtMagic:
.byte 0xd0, 0x0d, 0xfe, 0xed
.LArm64LinuxMagic:
.byte 0x41, 0x52, 0x4d, 0x64
@@ -43,17 +40,15 @@ GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdCoreCount)
// );
ASM_PFX(ArmPlatformPeiBootAction):
mov x29, x30 // preserve LR
mov x28, x0 // preserve DTB pointer
mov x27, x1 // preserve base of image pointer
//
// If we are booting from RAM using the Linux kernel boot protocol, x0 will
// point to the DTB image in memory. Otherwise, we are just coming out of
// reset, and x0 will be 0. Check also the FDT magic.
// reset, and x0 will be 0.
//
cbz x0, .Lout
ldr w8, .LFdtMagic
ldr w9, [x0]
cmp w8, w9
bne .Lout
//
// The base of the runtime image has been preserved in x1. Check whether
@@ -80,36 +75,30 @@ ASM_PFX(ArmPlatformPeiBootAction):
str x1, [x8]
str x7, [x9]
//
// Discover the memory size and offset from the DTB, and record in the
// respective PCDs. This will also return false if a corrupt DTB is
// encountered. Since we are calling a C function, use the window at the
// beginning of the FD image as a temp stack.
//
adr x1, PcdGet64 (PcdSystemMemorySize)
adr x2, PcdGet64 (PcdSystemMemoryBase)
mov sp, x7
bl FindMemnode
cbz x0, .Lout
//
// Copy the DTB to the slack space right after the 64 byte arm64/Linux style
// image header at the base of this image (defined in the FDF), and record the
// pointer in PcdDeviceTreeInitialBaseAddress.
//
adr x8, PcdGet64 (PcdDeviceTreeInitialBaseAddress)
add x1, x1, #0x40
str x1, [x8]
add x27, x27, #0x40
str x27, [x8]
ldr w8, [x0, #4] // get DTB size (BE)
mov x9, x1
rev w8, w8
add x8, x8, x0
0:ldp x6, x7, [x0], #16
stp x6, x7, [x9], #16
cmp x0, x8
blt 0b
//
// Discover the memory size and offset from the DTB, and record in the
// respective PCDs
//
mov x0, x1
bl find_memnode // returns (size, base) size in (x0, x1)
cbz x0, .Lout
adr x8, PcdGet64 (PcdSystemMemorySize)
adr x9, PcdGet64 (PcdSystemMemoryBase)
str x0, [x8]
str x1, [x9]
mov x0, x27
mov x1, x28
bl CopyFdt
.Lout:
ret x29