riscv64 regression

[Alex]

Seeing a regression in functionality across multiple devices. I did a bit of bisecting, here's the path:

Thu May 5 19:37:22 2022 -0400
working: 03b873b4f41010e4f85a72dd59016bb0b123dde1 gcc 11.1.0
no build: 03b873b4f41010e4f85a72dd59016bb0b123dde1 gcc 12.2.0 unrecognized opcode `csrs sstatus,a5', extension `zicsr' required

Wed Oct 12 14:59:51 2022 +0200
broke: e67f34f778baabd76f2e0e645a409fed14d2d156 gcc 12.2.0 (fixes zicsr issue)

Mon Dec 19 08:45:26 2022 -0500
broke: 2243922edca9f56a9d5519b9d6e36f5d7a18434d gcc 12.2.0

Mon Jan 2 09:36:13 2023 -0500
broke: 582e3c9fb2337c2f49faa73ac86dde25f4d56901 gcc 12.2.0
Working boots our EFI loader fine.
Broke boots see similar Load Access faults multiple platforms (qemu, unmatched, StarFive):
StarFive VisionFive 2:

SATP: 0x80000000000fbe03
Calling ExitBootServices. So long, EFI!
clk u5_dw_i2c_clk_core already disabled
clk u5_dw_i2c_clk_apb already disabled
Unhandled exception: Load access fault
EPC: 00000000fe6dc496 RA: 00000000fe6dc488 TVAL: 0000000000000000
EPC: 000000003e98e496 RA: 000000003e98e488 reloc adjusted

SP: 00000000ff73b868 GP: 0000000000000000 TP: 0000000000000001
T0: 00000000fbf28135 T1: 0000000000000008 T2: 0000000000000000
S0: 0000000000000021 S1: 0000000000000000 A0: 0000000000000021
A1: 0000000000000000 A2: 0000000000000001 A3: 00000000ff73b968
A4: 0000000000000001 A5: 00000000000001ff A6: 0000000000000020
A7: 000000000000000a S2: 00000000ff73b968 S3: ffffffc0020940c6
S4: 00000000fe713c80 S5: 00000000ff73be94 S6: 00000000ff73beb8
S7: 00000000ff73beb0 S8: 00000000ff73bea8 S9: 00000000ff73be98
S10: 00000000fe6fc288 S11: 00000000fe713c70 T3: 0000000074757074
T4: ffffffffffffffe8 T5: 0000000000000000 T6: 00000000fbf2810d

Code: 0b31 0793 1ff0 c763 02a7 842a 5863 00a0 (609c)
UEFI image [0x00000000fe6d0000:0x00000000fe720fff] pc=0xc496 '/efibootbootriscv64.efi'
My questions:

 * Is GCC 12.2 known broken / unreliable for riscv64 builds of u-boot?
 * Has anything else changed around memory management on riscv64 between May 2022 and Oct 2022

 -- Alex