Commit graph

20686 commits

Author SHA1 Message Date
Giulio Benetti
1f3555d906 ARM: dts: imxrt1050-evk: move all u-boot, dm-spl to imxrt1050-evk-u-boot.dtsi file
At the moment a lot of u-boot,dm-spl properties are present in board .dts
file but this is not correct since u-boot,dm-spl property is u-boot
specific and must be listed into the separate imrt1050-evk-u-boot.dtsi
file. So let's move every u-boot,dm-spl property present in
imxrt1050-evk.dts to imxrt1050-evk-u-boot.dtsi file.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:03:08 +02:00
Giulio Benetti
31f0e58527 ARM: dts: imxrt1050-evk: remove u-boot,dm-spl
We don't need lcdif to be enable in SPL, so let's remove u-boot,dm-spl.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
a9a5c33d57 ARM: dts: imxrt1050: set lcdif clocks according to mxsfb driver
Lcdif needs both "pix" and "axi" clocks to be enabled so let's add them to
lcdif node.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
f2d91e606b ARM: dts: imxrt1050: move lcdif assigned clock to dtsi
Since we assume pll5 is the default lcdif clock source let's move
assigned-clocks(-parents) properties to .dtsi file.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
6f6f03af0e ARM: dts: imxrt1050-evk: add device_type = "memory" to memory node
Now device_type = "memory" is mandatory to allow u-boot to read memory
node, so let's add it to memory node.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
0684ec8a9d ARM: dts: imxrt1050-evk-u-boot: make gpt1 present for SPL
Timer needs to be already enabled in spl, so let's add its node to spl dtb.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
7892f3eba1 ARM: dts: imxrt1050-evk: set gpt1 as tick-timer for u-boot
Let's set gpt1 as u-boot timer.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
7eacc427bb ARM: dts: imxrt1050-evk: enable gpt1 timer
Enable gpt1 timer.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
5790db9283 ARM: dts: imxrt1050: add gpt1 node
Add gpt1 node for using it as timer.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
6cd7a9b850 ARM: dts: imxrt1050: add node label to osc
Let's add node label to osc to be used as clock source for other nodes.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
d956990c69 ARM: dts: imxrt1020-evk: add device_type = "memory" to memory node
Now device_type = "memory" is mandatory to allow u-boot to read memory
node, so let's add it to memory node.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
faa4e95b5c ARM: dts: imxrt1020-evk-u-boot: make gpt1 present for SPL
Timer needs to be already enabled in spl, so let's add its node to spl dtb.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
e5d10f4442 ARM: dts: imxrt1020-evk: set gpt1 as tick-timer for u-boot
Let's set gpt1 as u-boot timer.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
bc4944051e ARM: dts: imxrt1020-evk: enable gpt1 timer
Enable gpt1 timer.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
df243c93d3 ARM: dts: imxrt1020: add gpt1 node
Add gpt1 node for using it as timer.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
bfdbe871a0 ARM: dts: imxrt1020: add node label to osc
Let's add node label to osc to be used as clock source for other nodes.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Giulio Benetti
55ad612306 arm: imxrt: soc: make mpu regions generic
This mpu handling works for every i.MXRT SoC that we have, so let's
generalize imxrt1050_region_config to imxrt_region_config.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2021-06-09 13:01:33 +02:00
Heinrich Schuchardt
205b9f5100 sandbox: correct determination of the text base
os_find_text_base() assumes that first line of /proc/self/maps holds
information about the text. Hence we must call the function before calling
os_malloc() which calls mmap(0x10000000,).

Failure to do so has led to incorrect values for pc_reloc when an
exception was reported

    => exception undefined

    Illegal instruction
    pc = 0x5628d82e9d3c, pc_reloc = 0x5628c82e9d3c

as well as incorrect output of the bdinfo command

    => bdinfo
    relocaddr   = 0x0000000007858000
    reloc off   = 0x0000000010000000

Fixes: b308d9fd18 ("sandbox: Avoid using malloc() for system state")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-06-05 07:35:47 -06:00
Pali Rohár
079b35a261 arm: a37xx: pci: Increase PCIe MEM size from 16 MiB to 127 MiB
For some configurations with more PCIe cards and PCIe bridges, 16 MiB of
PCIe MEM space may not be enough. Since TF-A already allocates a 128 MiB
CPU window for PCIe, and since IO port space is only 64 KiB in total,
use all the remaining space (64 + 32 + 16 + 8 + 4 + 2 + 1 = 127 MiB) for
PCIe MEM.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
2021-06-04 11:32:41 +02:00
Pali Rohár
4a82fca8e3 arm: a37xx: pci: Fix a3700_fdt_fix_pcie_regions() function
Current version of this function uses a lot of incorrect assumptions about
the `ranges` DT property:

 * parent(#address-cells) == 2
 * #size-cells == 2
 * number of entries == 2
 * address size of first entry == 0x1000000
 * second child address entry == base + 0x1000000

Trying to increase PCIe MEM space to more than 16 MiB leads to an overlap
with PCIe IO space, and trying to define additional MEM space (as a third
entry in the `ranges` DT property) causes U-Boot to crash when booting the
kernel.

  ## Flattened Device Tree blob at 04f00000
     Booting using the fdt blob at 0x4f00000
     Loading Device Tree to 000000001fb01000, end 000000001fb08f12 ... OK
  ERROR: board-specific fdt fixup failed: <unknown error>
   - must RESET the board to recover.

Fix a3700_fdt_fix_pcie_regions() to properly parse and update all addresses
in the `ranges` property according to
https://elinux.org/Device_Tree_Usage#PCI_Address_Translation

Now it is possible to increase PCIe MEM space from 16 MiB to maximal value
of 127 MiB.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Fixes: cb2ddb291e ("arm64: mvebu: a37xx: add device-tree fixer for PCIe regions")
Reviewed-by: Stefan Roese <sr@denx.de>
2021-06-04 11:32:41 +02:00
Pali Rohár
46b679e3ec arm: a37xx: pci: Find PCIe controller node by compatible instead of path
Find PCIe DT node by compatible string instead of retrieving it by using
hardcoded DT path.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
2021-06-04 11:32:41 +02:00
Pali Rohár
a544d65f1d arm: a37xx: pci: Fix DT compatible string to Linux' DT compatible
Change DT compatible string for A3700 PCIe from 'marvell,armada-37xx-pcie'
to 'marvell,armada-3700-pcie' to make U-Boot A3700 PCIe DT node compatible
with Linux' DT node.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
2021-06-04 11:32:41 +02:00
Tom Rini
d8729a114e Merge https://source.denx.de/u-boot/custodians/u-boot-riscv
- SiFive FU740 and Unmatched support
2021-05-31 10:19:14 -04:00
Green Wan
c552debbd8 riscv: cpu: fu740: clear feature disable CSR
Clear feature disable CSR to turn on all features of hart. The detail
is specified at section, 'SiFive Feature Disable CSR', in user manual

https://sifive.cdn.prismic.io/sifive/aee0dd4c-d156-496e-a6c4-db0cf54bbe68_sifive_U74MC_rtl_full_20G1.03.00_manual.pdf

Signed-off-by: Green Wan <green.wan@sifive.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
2021-05-31 16:35:55 +08:00
Green Wan
70415e1e52 board: sifive: add HiFive Unmatched board support
Add defconfig and board support for HiFive Unmatched.

Signed-off-by: Green Wan <green.wan@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
2021-05-31 16:35:55 +08:00
Green Wan
1c07b0c562 riscv: dts: add SiFive Unmatched board support
Add dts files for SiFive Unmatched board.

Signed-off-by: Green Wan <green.wan@sifive.com>
Reviewed-by: Rick Chen <rick@andestech.com>
2021-05-31 16:35:54 +08:00
Green Wan
2113c0045c riscv: dts: add fu740 support
Add dts support for fu740. The HiFive Unmatched support is based on
fu740 cpu and drivers in following patch set.

Signed-off-by: Green Wan <green.wan@sifive.com>
[greentime.hu: set fu740 speed to 1.2GHz]
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
2021-05-31 16:35:54 +08:00
Green Wan
d56d79ed27 drivers: clk: add fu740 support
Add fu740 support. One abstract layer is added for supporting
multiple chips such as fu540 and fu740.

Signed-off-by: Green Wan <green.wan@sifive.com>
2021-05-31 16:35:54 +08:00
Green Wan
a74e9d899d riscv: cpu: fu740: Add support for cpu fu740
Add SiFive fu740 cpu to support RISC-V arch

Signed-off-by: Green Wan <green.wan@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-05-31 16:35:53 +08:00
Andre Przywara
6785434709 sunxi: Bring back SD card as MMC device 0
Commit 2243d19e56 ("mmc: mmc-uclass: Use dev_seq() to read aliases
node's index") now actually enforces U-Boot's device enumeration policy,
where explicitly named devices come first, then any other non-named
devices follow, without filling gaps.

For quite a while we have had an "mmc1 = &mmc2;" alias in our
sunxi-u-boot.dtsi, which now leads to the problem that the SD card
(which was always mmc device 0) now gets to be number 2.
This breaks quite some boot scripts, including our own distro boot
commands, and some other features looking at $mmc_bootdev, also
fastboot.

Just add an explicit mmc0 alias in the very same file to fix this and
restore the old behaviour.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reported-by: Samuel Holland <samuel@sholland.org>
Tested-by: Simon Baatz <gmbnomis@gmail.com>
2021-05-31 00:39:54 +01:00
Grzegorz Szymaszek
7bda7cee2d arm: dts: stm32mp157c-odyssey-som: enable the RNG1
Enable the true random number generator. It can be used, for example, to
generate partition UUIDs when partitioning with the gpt command. The
generator is already enabled in the device trees of several other
STM32MP1‐based boards, like DKx or DHCOM.

Signed-off-by: Grzegorz Szymaszek <gszymaszek@short.pl>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
2021-05-28 15:05:39 +02:00
Tom Rini
aab8b17e94 Merge tag 'ti-v2021.07-rc4' of https://source.denx.de/u-boot/custodians/u-boot-ti
- Fix reset for AM64 platforms
- Enable networking PHY driver for AM64
- Fix default R5F cluster setting in J7
2021-05-27 07:42:49 -04:00
Suman Anna
7194a95d13 arm: dts: k3-am642-sk: Add sysreset controller node
The AM64x SoC uses a central Device Management and Security Controller
(DMSC) processor that manages all the low-level device controls
including the system-wide SoC reset. The system-wide reset is managed
through the system reset driver.

Add a sysreset controller node as a child of the dmsc node to enable
the "reset" command from U-Boot prompt for the K3 AM642 SK.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
2021-05-27 14:53:14 +05:30
Suman Anna
a97ee92e4a arm: dts: k3-am642-evm: Add sysreset controller node
The AM64x SoC uses a central Device Management and Security Controller
(DMSC) processor that manages all the low-level device controls
including the system-wide SoC reset. The system-wide reset is managed
through the system reset driver.

Add a sysreset controller node as a child of the dmsc node to enable
the "reset" command from U-Boot prompt for the K3 AM642 EVM.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
2021-05-27 14:53:14 +05:30
Suman Anna
4ec04073ab arm: dts: k3-j721e: Fix up MAIN R5FSS cluster mode back to Split-mode
The default U-Boot environment variables and design are all set up for
both the MAIN R5FSS clusters to be in Split-mode. This is the setting
in v2021.01 U-Boot and the dt nodes are synched with the kernel binding
property names in commit 468ec2f3ef ("remoteproc: k3_r5: Sync to
upstreamed kernel DT property names") merged in v2021.04-rc2.

The modes for both the clusters got switched back to LockStep mode by
mistake in commit 70e167495a ("arm: dts: k3-j721e: Sync Linux v5.11-rc6
dts into U-Boot") also in v2021.04-rc2. This throws the following warning
messages when early-booting the cores using default env variables,

  k3_r5f_rproc r5f at 5d00000: Invalid op: Trying to start secondary core 7 in lockstep mode
  Load Remote Processor 3 with data at addr=0x82000000 98484 bytes: Failed!
  k3_r5f_rproc r5f at 5f00000: Invalid op: Trying to start secondary core 9 in lockstep mode
  Load Remote Processor 5 with data at addr=0x82000000 98484 bytes: Failed!

Fix this by switching back both the clusters to the expected Split-mode.
Make this mode change in the u-boot specific dtsi file to avoid such
sync overrides in the future until the kernel dts is also switched to
Split-mode by default.

Fixes: 70e167495a ("arm: dts: k3-j721e: Sync Linux v5.11-rc6 dts into U-Boot")
Reported-by: Minas Hambardzumyan <minas@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
2021-05-27 14:52:16 +05:30
Matt Merhar
f6c0d365d3 powerpc: fix regression in arch_initr_trap()
The assembly output of the arch_initr_trap() function differed by a
single byte after common.h was removed from traps.c:

 fff49a18 <arch_initr_trap>:
 fff49a18:      94 21 ff f0     stwu    r1,-16(r1)
 fff49a1c:      7c 08 02 a6     mflr    r0
 fff49a20:      90 01 00 14     stw     r0,20(r1)
-fff49a24:      80 62 00 44     lwz     r3,68(r2)
+fff49a24:      80 62 00 38     lwz     r3,56(r2)
 fff49a28:      4b ff 76 19     bl      fff41040 <trap_init>
 fff49a2c:      80 01 00 14     lwz     r0,20(r1)
 fff49a30:      38 60 00 00     li      r3,0
 fff49a34:      38 21 00 10     addi    r1,r1,16
 fff49a38:      7c 08 03 a6     mtlr    r0

This was causing a consistent hard lockup during the MMC read / loading
of the QoriQ FMan firmware on a P2041RDB board.

Re-adding the header causes identical assembly to be emitted and allows
the firmware loading and subsequent boot to succeed.

Fixes: 401d1c4f5d ("common: Drop asm/global_data.h from common header")
Signed-off-by: Matt Merhar <mattmerhar@protonmail.com>
2021-05-26 17:26:07 -04:00
Daniel Schwierzeck
5308a71db8 MIPS: remove deprecated qemu_mips board
Remove qemu_mips boards because DM migration doesn't make sense.
The board support for qemu_mips is already marked as deprecated
in Qemu in favour of the Malta board. Also qemu_mips support
has been removed from Linux a long time ago.

The official replacement is the Malta board. The same Malta U-Boot
image can be used with Qemu and on physical hardware.
All combinations of Big Endian and Little Endian as well as 32 bit
and 64 bit are supported.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
2021-05-25 15:35:06 +02:00
Marek Behún
34ccadcd33 ARM: don't use --gc-sections with LTO when using private libgcc
When using LTO, we can throw away the --gc-sections flag, but only if
using private libgcc.

When using system's libgcc, --gc-sections is still needed, otherwise
linking will fail due to undefined references to libc's symbols.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00
Marek Behún
75c7d10c1f ARM: don't use -ffunction-sections/-fdata-sections with LTO build
When building with LTO, using -ffunction-sections/-fdata-sections is not
useful anymore.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00
Marek Behún
8f9696510a ARM: make LTO available
Make LTO available for ARM architecture.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00
Marek Behún
37de198fa2 armv8: SPL: discard relocation information
For some reason when building SPL for ARMv8 with LTO, the relocation
information is not discarded.

Discard it explicitly in the linker script.

This fixes LTO build for imx8mm_venice_defconfig.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00
Marek Behún
baa977bd0f ARM: omap3: fix LTO for DM3730 (and possibly other omap3 boards)
Adam Ford says that DM3730 needs board.c compiled without LTO flags.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Tested-by: Adam Ford <aford173@gmail.com>
2021-05-24 14:21:30 -04:00
Marek Behún
79dec66ca7 ARM: fix LTO for rockchip and samsung
When building with LTO, the compiler complains about type mismatch of
function usb_gadget_handle_interrupts(). This function is defined
without parameters in files
  arch/arm/mach-rockchip/board.c
  board/samsung/common/exynos5-dt.c
but it should have one parameter, int index.

Fix this.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
2021-05-24 14:21:30 -04:00
Marek Behún
9d3918f3fd ARM: fix LTO for seaboard
When seaboard_defconfig is compiled with LTO, the compiler complains
about some instructions not being supported in ARM mode.

This is caused by arch/arm/mach-tegra/tegra20/warmboot_avp.c having
different CFLAGS declared in Makefile. This file needs to be compiled
without LTO.

Fix this by removing -flto for this file.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00
Marek Behún
e8bb990fe7 ARM: imx8m: fix imx_eqos_txclk_set_rate() type mismatch for LTO
When building imx8mp_evk_defconfig with LTO, the compiler complains
about type mismatch of function imx_eqos_txclk_set_rate() in file
  drivers/net/dwc_eth_qos.c:845:12
which contains a weak definition of this function, vs file
  arch/arm/mach-imx/imx8m/clock_imx8mm.c
which contains an implementation.

Change the type of this function in the implementation to fix this.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-05-24 14:21:30 -04:00
Marek Behún
3cd7541f93 ARM: kona: fix clk_bsc_enable() type mismatch for LTO
When building with LTO, the compiler complains about type mismatch of
function clk_bsc_enable() in file:
  arch/arm/cpu/armv7/kona-common/clk-stubs.c
vs other files that define or use this function:
  warning: type of ‘clk_bsc_enable’ does not match original declaration.

Change the type of this function to that of the other usages.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-05-24 14:21:30 -04:00
Marek Behún
9493e96e54 ARM: fix LTO for keystone
When building keystone with LTO the compiler complains:
  Error: selected processor does not support `smc #0' in Thumb mode

Fix this by removing -flto for the file implementing these SMC calls.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
2021-05-24 14:21:30 -04:00
Marek Behún
b83120df79 ARM: fix LTO for imx28_xea
When imx28_xea_defconfig is built with LTO, the compiler complains about
the two different declarations of _start:
   include/asm-generic/sections.h    as  extern void _start(void);
   arch/arm/cpu/arm926ejs/mxs/mxs.c  as  extern uint32_t _start;

Fix this.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-05-24 14:21:30 -04:00
Marek Behún
e5fc9037dd ARM: fix LTO build for some thumb-interwork cases
Fix LTO build for some thumb-interwork usecases (such as for
da850evm_defconfig), where inline assmebly such as
  mrc p15,0,r2,c1,c0,0
causes the compiler to fail during LTO linking with
  Error: selected processor does not support `mrc p15,0,r2,c1,c0,0'
         in Thumb mode

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00
Marek Behún
86c5e21013 ARM: make gd a function call for LTO and set via set_gd()
On ARM, the gd pointer is stored in registers r9 / x18. For this the
-ffixed-r9 / -ffixed-x18 flag is used when compiling, but using global
register variables causes errors when building with LTO, and these
errors are very difficult to overcome.

Richard Biener says [1]:
  Note that global register vars shouldn't be used with LTO and if they
  are restricted to just a few compilation units the recommended fix is
  to build those CUs without -flto.

We cannot do this for U-Boot since all CUs use -ffixed-reg flag.

It seems that with LTO we could in fact store the gd pointer differently
and gain performance or size benefit by allowing the compiler to use
r9 / x18. But this would need more work.

So for now, when building with LTO, go the clang way, and instead of
declaring gd a global register variable, we make it a function call via
macro.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68384

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-24 14:21:30 -04:00