u-boot.git/lib/efi_loader/efi_variable_tee.c, branch v2024.01

arm_ffa: efi: introduce FF-A MM communication

2023-08-08T14:22:03+00:00

Add MM communication support using FF-A transport

This feature allows accessing MM partitions services through
EFI MM communication protocol. MM partitions such as StandAlonneMM
or smm-gateway secure partitions which reside in secure world.

An MM shared buffer and a door bell event are used to exchange
the data.

The data is used by EFI services such as GetVariable()/SetVariable()
and copied from the communication buffer to the MM shared buffer.

The secure partition is notified about availability of data in the
MM shared buffer by an FF-A message (door bell).

On such event, MM SP can read the data and updates the MM shared
buffer with the response data.

The response data is copied back to the communication buffer and
consumed by the EFI subsystem.

MM communication protocol supports FF-A 64-bit direct messaging.

We tested the FF-A MM communication on the Corstone-1000 platform.

We ran the UEFI SCT test suite containing EFI setVariable, getVariable and
getNextVariable tests which involve FF-A MM communication and all tests
are passing with the current changes.

We made the SCT test reports (part of the ACS results) public following the
latest Corstone-1000 platform software release. Please find the test
reports at [1].

[1]: https://gitlab.arm.com/arm-reference-solutions/arm-reference-solutions-test-report/-/tree/master/embedded-a/corstone1000/CORSTONE1000-2023.06/acs_results_fpga.zip

Signed-off-by: Abdellatif El Khlifi 
Tested-by: Gowtham Suresh Kumar 
Reviewed-by: Simon Glass 
Cc: Tom Rini 
Cc: Ilias Apalodimas 
Cc: Jens Wiklander 
Reviewed-by: Ilias Apalodimas 
Reviewed-by: Tom Rini

Revert "Merge branch '2023-07-24-introduce-FF-A-suppport'"

2023-07-24T23:51:05+00:00

This reverts commit d927d1a80843e1c3e2a3f0b8f6150790bef83da1, reversing
changes made to c07ad9520c6190070513016fdb495d4703a4a853.

These changes do not pass CI currently.

Signed-off-by: Tom Rini

arm_ffa: efi: introduce FF-A MM communication

2023-07-24T19:30:03+00:00

Add MM communication support using FF-A transport

This feature allows accessing MM partitions services through
EFI MM communication protocol. MM partitions such as StandAlonneMM
or smm-gateway secure partitions which reside in secure world.

An MM shared buffer and a door bell event are used to exchange
the data.

The data is used by EFI services such as GetVariable()/SetVariable()
and copied from the communication buffer to the MM shared buffer.

The secure partition is notified about availability of data in the
MM shared buffer by an FF-A message (door bell).

On such event, MM SP can read the data and updates the MM shared
buffer with the response data.

The response data is copied back to the communication buffer and
consumed by the EFI subsystem.

MM communication protocol supports FF-A 64-bit direct messaging.

Signed-off-by: Abdellatif El Khlifi 
Tested-by: Gowtham Suresh Kumar 
Reviewed-by: Simon Glass 
Cc: Tom Rini 
Cc: Ilias Apalodimas 
Cc: Jens Wiklander

efi_loader: Set variable attributes when EFI_BUFFER_TOO_SMALL is returned

2022-03-20T10:03:06+00:00

Starting UEFI Spec 2.8 we must fill in the variable attributes when
GetVariable() returns EFI_BUFFER_TOO_SMALL and Attributes is non-NULL.

This code was written with 2.7 in mind so let's move the code around a
bit and fill in the attributes EFI_BUFFER_TOO_SMALL is returned

Signed-off-by: Ilias Apalodimas 
Reviewed-by: Heinrich Schuchardt

efi: Use 16-bit unicode strings

2022-02-03T17:16:01+00:00

At present we use wide characters for unicode but this is not necessary.
Change the code to use the 'u' literal instead. This helps to fix build
warnings for sandbox on rpi.

Signed-off-by: Simon Glass 
Suggested-by: Heinrich Schuchardt 
Reviewed-by: Heinrich Schuchardt

efi_loader: Don't limit the StMM buffer size explicitly

2021-12-26T05:49:14+00:00

Currently we allow and explicitly check a single shared page with
StandAloneMM.  This is dictated by OP-TEE which runs the application.
However there's no way for us dynamically discover the number of pages we
are allowed to use.  Since writing big EFI signature list variable
requires more than a page, OP-TEE has bumped the number of shared pages to
four.

Let's remove our explicit check and allow the request to reach OP-TEE even
if it's bigger than what it supports.  There's no need to sanitize the
number of pages internally.  OP-TEE will fail if we try to write more
than it's allowed. The error will just trigger later on,  during the
StMM access.

While at it add an error message to help users figure out what failed.

Signed-off-by: Ilias Apalodimas 
Tested-by: Ying-Chun Liu (PaulLiu) 

Signed-off-by: Ilias Apalodimas

efi_loader: treat UEFI variable name as const

2021-10-25T19:13:06+00:00

UEFI variable names are typically constants and hence should be defined as
const. Unfortunately some of our API functions do not define the parameters
for UEFI variable names as const. This requires unnecessary conversions.

Adjust parameters of several internal functions to tre UEFI variable names
as const.

Signed-off-by: Heinrich Schuchardt 
Reviewed-by: Ilias Apalodimas

efi_loader: Avoid emitting efi_var_buf to .GOT

2021-01-20T07:17:17+00:00

Atish reports that on RISC-V, accessing the EFI variables causes
a kernel panic. An objdump of the file verifies that, since the
global pointer for efi_var_buf ends up in .GOT section which is
not mapped in virtual address space for Linux.



0000000000000084 :
  84:   715d                    addi    sp,sp,-80

* objdump -dr
0000000000000086 <.LCFI2>:
  86:   e0a2                    sd  s0,64(sp)
  88:   fc26                    sd  s1,56(sp)
  8a:   e486                    sd  ra,72(sp)
  8c:   f84a                    sd  s2,48(sp)
  8e:   f44e                    sd  s3,40(sp)
  90:   f052                    sd  s4,32(sp)
  92:   ec56                    sd  s5,24(sp)
  94:   00000497            auipc   s1,0x0
            94: R_RISCV_GOT_HI20    efi_var_buf
  98:   0004b483            ld  s1,0(s1) # 94 <.LCFI2+0xe>
            98: R_RISCV_PCREL_LO12_I    .L0
            98: R_RISCV_RELAX   *ABS*

* objdump -t
0000000000000084 g     F .text.efi_runtime  00000000000000b8 efi_var_mem_find

With the patch applied:

* objdump -dr
0000000000000086 <.LCFI2>:
  86:   e0a2                    sd  s0,64(sp)
  88:   fc26                    sd  s1,56(sp)
  8a:   e486                    sd  ra,72(sp)
  8c:   f84a                    sd  s2,48(sp)
  8e:   f44e                    sd  s3,40(sp)
  90:   f052                    sd  s4,32(sp)
  92:   ec56                    sd  s5,24(sp)
  94:   00000497            auipc   s1,0x0
            94: R_RISCV_PCREL_HI20  .LANCHOR0
            94: R_RISCV_RELAX   *ABS*
  98:   00048493            mv  s1,s1
            98: R_RISCV_PCREL_LO12_I    .L0
            98: R_RISCV_RELAX   *ABS*

* objdump -t
0000000000000008 l     O .data.efi_runtime  0000000000000008 efi_var_buf

On arm64 this works, because there's no .GOT entries for this
and everything is converted to relative references.

* objdump -dr (identical pre-post patch, only the new function shows up)
00000000000000b4 :
  b4:   aa0003ee    mov x14, x0
  b8:   9000000a    adrp    x10, 0 
            b8: R_AARCH64_ADR_PREL_PG_HI21  .data.efi_runtime
  bc:   91000140    add x0, x10, #0x0
            bc: R_AARCH64_ADD_ABS_LO12_NC   .data.efi_runtime
  c0:   aa0103ed    mov x13, x1
  c4:   79400021    ldrh    w1, [x1]
  c8:   aa0203eb    mov x11, x2
  cc:   f9400400    ldr x0, [x0, #8]
  d0:   b940100c    ldr w12, [x0, #16]
  d4:   8b0c000c    add x12, x0, x12

So let's switch efi_var_buf to static and create a helper function for
anyone that needs to update it.

Fixes: e01aed47d6a0 ("efi_loader: Enable run-time variable support for tee based variables")
Reported-by: Atish Patra 
Tested-by: Atish Patra 
Signed-off-by: Ilias Apalodimas 
Reviewed-by: Heinrich Schuchardt

efi_loader: Extra checks while opening an OPTEE session

2020-12-26T11:47:46+00:00

When opening an OP-TEE session we need to check the internal return
value of OP-TEE call arguments as well the return code of the
function itself.
The code was also ignoring to close the OP-TEE session in case the
shared memory registration failed.

Fixes: f042e47e8fb43 ("efi_loader: Implement EFI variable handling via OP-TEE")
Signed-off-by: Ilias Apalodimas 
Signed-off-by: Heinrich Schuchardt

efi_loader: Enable run-time variable support for tee based variables

2020-08-01T09:57:41+00:00

We recently added functions for storing/restoring variables
from a file to a memory backed buffer marked as __efi_runtime_data
commit f1f990a8c958 ("efi_loader: memory buffer for variables")
commit 5f7dcf079de8 ("efi_loader: UEFI variable persistence")

Using the same idea we now can support GetVariable() and GetNextVariable()
on the OP-TEE based variables as well.

So let's re-arrange the code a bit and move the commmon code for
accessing variables out of efi_variable.c. Create common functions for
reading variables from memory that both implementations can use on
run-time. Then just use those functions in the run-time variants of the
OP-TEE based EFI variable implementation and initialize the memory
buffer on ExitBootServices()

Signed-off-by: Ilias Apalodimas 
Reviewed-by: Heinrich Schuchardt