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From: Alistair Francis <alistair.francis@opensource.wdc.com>
To: qemu-devel@nongnu.org
Cc: alistair23@gmail.com, Jessica Clarke <jrtc27@jrtc27.com>,
	Alistair Francis <alistair.francis@wdc.com>
Subject: [PULL 88/88] hw/riscv: Use load address rather than entry point for fw_dynamic next_addr
Date: Mon, 20 Dec 2021 14:57:05 +1000	[thread overview]
Message-ID: <20211220045705.62174-89-alistair.francis@opensource.wdc.com> (raw)
In-Reply-To: <20211220045705.62174-1-alistair.francis@opensource.wdc.com>

From: Jessica Clarke <jrtc27@jrtc27.com>

The original BBL boot method had the kernel embedded as an opaque blob
that was blindly jumped to, which OpenSBI implemented as fw_payload.
OpenSBI then implemented fw_jump, which allows the payload to be loaded
elsewhere, but still blindly jumps to a fixed address at which the
kernel is to be loaded. Finally, OpenSBI introduced fw_dynamic, which
allows the previous stage to inform it where to jump to, rather than
having to blindly guess like fw_jump, or embed the payload as part of
the build like fw_payload. When used with an opaque binary (i.e. the
output of objcopy -O binary), it matches the behaviour of the previous
methods. However, when used with an ELF, QEMU currently passes on the
ELF's entry point address, which causes a discrepancy compared with all
the other boot methods if that entry point is not the first instruction
in the binary.

This difference specific to fw_dynamic with an ELF is not apparent when
booting Linux, since its entry point is the first instruction in the
binary. However, FreeBSD has a separate ELF entry point, following the
calling convention used by its bootloader, that differs from the first
instruction in the binary, used for the legacy SBI entry point, and so
the specific combination of QEMU's default fw_dynamic firmware with
booting FreeBSD as an ELF rather than a raw binary does not work.

Thus, align the behaviour when loading an ELF with the behaviour when
loading a raw binary; namely, use the base address of the loaded kernel
in place of the entry point.

The uImage code is left as-is in using the U-Boot header's entry point,
since the calling convention for that entry point is the same as the SBI
one and it mirrors what U-Boot will do.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211214032456.70203-1-jrtc27@jrtc27.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 hw/riscv/boot.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 519fa455a1..f67264374e 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -151,12 +151,19 @@ target_ulong riscv_load_kernel(const char *kernel_filename,
                                target_ulong kernel_start_addr,
                                symbol_fn_t sym_cb)
 {
-    uint64_t kernel_entry;
+    uint64_t kernel_load_base, kernel_entry;
 
+    /*
+     * NB: Use low address not ELF entry point to ensure that the fw_dynamic
+     * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
+     * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
+     * the (expected) load address load address. This allows kernels to have
+     * separate SBI and ELF entry points (used by FreeBSD, for example).
+     */
     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
-                         &kernel_entry, NULL, NULL, NULL, 0,
+                         NULL, &kernel_load_base, NULL, NULL, 0,
                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
-        return kernel_entry;
+        return kernel_load_base;
     }
 
     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
-- 
2.31.1



  parent reply	other threads:[~2021-12-20  7:04 UTC|newest]

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-20  4:55 [PULL 00/88] riscv-to-apply queue Alistair Francis
2021-12-20  4:55 ` [PULL 01/88] target/riscv: zfh: half-precision load and store Alistair Francis
2021-12-20  4:55 ` [PULL 02/88] target/riscv: zfh: half-precision computational Alistair Francis
2021-12-20  4:55 ` [PULL 03/88] target/riscv: zfh: half-precision convert and move Alistair Francis
2021-12-20  4:55 ` [PULL 04/88] target/riscv: zfh: half-precision floating-point compare Alistair Francis
2021-12-20  4:55 ` [PULL 05/88] target/riscv: zfh: half-precision floating-point classify Alistair Francis
2021-12-20  4:55 ` [PULL 06/88] target/riscv: zfh: add Zfh cpu property Alistair Francis
2021-12-20  4:55 ` [PULL 07/88] target/riscv: zfh: implement zfhmin extension Alistair Francis
2021-12-20  4:55 ` [PULL 08/88] target/riscv: zfh: add Zfhmin cpu property Alistair Francis
2021-12-20  4:55 ` [PULL 09/88] target/riscv: drop vector 0.7.1 and add 1.0 support Alistair Francis
2021-12-20  4:55 ` [PULL 10/88] target/riscv: Use FIELD_EX32() to extract wd field Alistair Francis
2021-12-20  4:55 ` [PULL 11/88] target/riscv: rvv-1.0: add mstatus VS field Alistair Francis
2021-12-20  4:55 ` [PULL 12/88] target/riscv: rvv-1.0: set mstatus.SD bit if mstatus.VS is dirty Alistair Francis
2021-12-20  4:55 ` [PULL 13/88] target/riscv: rvv-1.0: add sstatus VS field Alistair Francis
2021-12-20  4:55 ` [PULL 14/88] target/riscv: rvv-1.0: introduce writable misa.v field Alistair Francis
2021-12-20  4:55 ` [PULL 15/88] target/riscv: rvv-1.0: add translation-time vector context status Alistair Francis
2021-12-20  4:55 ` [PULL 16/88] target/riscv: rvv-1.0: remove rvv related codes from fcsr registers Alistair Francis
2021-12-20  4:55 ` [PULL 17/88] target/riscv: rvv-1.0: add vcsr register Alistair Francis
2021-12-20  4:55 ` [PULL 18/88] target/riscv: rvv-1.0: add vlenb register Alistair Francis
2021-12-20  4:55 ` [PULL 19/88] target/riscv: rvv-1.0: check MSTATUS_VS when accessing vector csr registers Alistair Francis
2021-12-20  4:55 ` [PULL 20/88] target/riscv: rvv-1.0: remove MLEN calculations Alistair Francis
2021-12-20  4:55 ` [PULL 21/88] target/riscv: rvv-1.0: add fractional LMUL Alistair Francis
2021-12-20  4:55 ` [PULL 22/88] target/riscv: rvv-1.0: add VMA and VTA Alistair Francis
2021-12-20  4:56 ` [PULL 23/88] target/riscv: rvv-1.0: update check functions Alistair Francis
2021-12-20  4:56 ` [PULL 24/88] target/riscv: introduce more imm value modes in translator functions Alistair Francis
2021-12-20  4:56 ` [PULL 25/88] target/riscv: rvv:1.0: add translation-time nan-box helper function Alistair Francis
2021-12-20  4:56 ` [PULL 26/88] target/riscv: rvv-1.0: remove amo operations instructions Alistair Francis
2021-12-20  4:56 ` [PULL 27/88] target/riscv: rvv-1.0: configure instructions Alistair Francis
2021-12-20  4:56 ` [PULL 28/88] target/riscv: rvv-1.0: stride load and store instructions Alistair Francis
2021-12-20  4:56 ` [PULL 29/88] target/riscv: rvv-1.0: index " Alistair Francis
2021-12-20  4:56 ` [PULL 30/88] target/riscv: rvv-1.0: fix address index overflow bug of indexed load/store insns Alistair Francis
2021-12-20  4:56 ` [PULL 31/88] target/riscv: rvv-1.0: fault-only-first unit stride load Alistair Francis
2021-12-20  4:56 ` [PULL 32/88] target/riscv: rvv-1.0: load/store whole register instructions Alistair Francis
2021-12-20  4:56 ` [PULL 33/88] target/riscv: rvv-1.0: update vext_max_elems() for load/store insns Alistair Francis
2021-12-20  4:56 ` [PULL 34/88] target/riscv: rvv-1.0: take fractional LMUL into vector max elements calculation Alistair Francis
2021-12-20  4:56 ` [PULL 35/88] target/riscv: rvv-1.0: floating-point square-root instruction Alistair Francis
2021-12-20  4:56 ` [PULL 36/88] target/riscv: rvv-1.0: floating-point classify instructions Alistair Francis
2021-12-20  4:56 ` [PULL 37/88] target/riscv: rvv-1.0: count population in mask instruction Alistair Francis
2021-12-20  4:56 ` [PULL 38/88] target/riscv: rvv-1.0: find-first-set mask bit instruction Alistair Francis
2021-12-20  4:56 ` [PULL 39/88] target/riscv: rvv-1.0: set-X-first mask bit instructions Alistair Francis
2021-12-20  4:56 ` [PULL 40/88] target/riscv: rvv-1.0: iota instruction Alistair Francis
2021-12-20  4:56 ` [PULL 41/88] target/riscv: rvv-1.0: element index instruction Alistair Francis
2021-12-20  4:56 ` [PULL 42/88] target/riscv: rvv-1.0: allow load element with sign-extended Alistair Francis
2021-12-20  4:56 ` [PULL 43/88] target/riscv: rvv-1.0: register gather instructions Alistair Francis
2021-12-20  4:56 ` [PULL 44/88] target/riscv: rvv-1.0: integer scalar move instructions Alistair Francis
2021-12-20  4:56 ` [PULL 45/88] target/riscv: rvv-1.0: floating-point move instruction Alistair Francis
2021-12-20  4:56 ` [PULL 46/88] target/riscv: rvv-1.0: floating-point scalar move instructions Alistair Francis
2021-12-20  4:56 ` [PULL 47/88] target/riscv: rvv-1.0: whole register " Alistair Francis
2021-12-20  4:56 ` [PULL 48/88] target/riscv: rvv-1.0: integer extension instructions Alistair Francis
2021-12-20  4:56 ` [PULL 49/88] target/riscv: rvv-1.0: single-width averaging add and subtract instructions Alistair Francis
2021-12-20  4:56 ` [PULL 50/88] target/riscv: rvv-1.0: single-width bit shift instructions Alistair Francis
2021-12-20  4:56 ` [PULL 51/88] target/riscv: rvv-1.0: integer add-with-carry/subtract-with-borrow Alistair Francis
2021-12-20  4:56 ` [PULL 52/88] target/riscv: rvv-1.0: narrowing integer right shift instructions Alistair Francis
2021-12-20  4:56 ` [PULL 53/88] target/riscv: rvv-1.0: widening integer multiply-add instructions Alistair Francis
2021-12-20  4:56 ` [PULL 54/88] target/riscv: rvv-1.0: single-width saturating add and subtract instructions Alistair Francis
2021-12-20  4:56 ` [PULL 55/88] target/riscv: rvv-1.0: integer comparison instructions Alistair Francis
2021-12-20  4:56 ` [PULL 56/88] target/riscv: rvv-1.0: floating-point compare instructions Alistair Francis
2021-12-20  4:56 ` [PULL 57/88] target/riscv: rvv-1.0: mask-register logical instructions Alistair Francis
2021-12-20  4:56 ` [PULL 58/88] target/riscv: rvv-1.0: slide instructions Alistair Francis
2021-12-20  4:56 ` [PULL 59/88] target/riscv: rvv-1.0: floating-point " Alistair Francis
2021-12-20  4:56 ` [PULL 60/88] target/riscv: rvv-1.0: narrowing fixed-point clip instructions Alistair Francis
2021-12-20  4:56 ` [PULL 61/88] target/riscv: rvv-1.0: single-width floating-point reduction Alistair Francis
2021-12-20  4:56 ` [PULL 62/88] target/riscv: rvv-1.0: widening floating-point reduction instructions Alistair Francis
2021-12-20  4:56 ` [PULL 63/88] target/riscv: rvv-1.0: single-width scaling shift instructions Alistair Francis
2021-12-20  4:56 ` [PULL 64/88] target/riscv: rvv-1.0: remove widening saturating scaled multiply-add Alistair Francis
2021-12-20  4:56 ` [PULL 65/88] target/riscv: rvv-1.0: remove vmford.vv and vmford.vf Alistair Francis
2021-12-20  4:56 ` [PULL 66/88] target/riscv: rvv-1.0: remove integer extract instruction Alistair Francis
2021-12-20  4:56 ` [PULL 67/88] target/riscv: rvv-1.0: floating-point min/max instructions Alistair Francis
2021-12-20  4:56 ` [PULL 68/88] target/riscv: introduce floating-point rounding mode enum Alistair Francis
2021-12-20  4:56 ` [PULL 69/88] target/riscv: rvv-1.0: floating-point/integer type-convert instructions Alistair Francis
2021-12-20  4:56 ` [PULL 70/88] target/riscv: rvv-1.0: widening floating-point/integer type-convert Alistair Francis
2021-12-20  4:56 ` [PULL 71/88] target/riscv: add "set round to odd" rounding mode helper function Alistair Francis
2021-12-20  4:56 ` [PULL 72/88] target/riscv: rvv-1.0: narrowing floating-point/integer type-convert Alistair Francis
2021-12-20  4:56 ` [PULL 73/88] target/riscv: rvv-1.0: relax RV_VLEN_MAX to 1024-bits Alistair Francis
2021-12-20  4:56 ` [PULL 74/88] target/riscv: rvv-1.0: implement vstart CSR Alistair Francis
2021-12-20  4:56 ` [PULL 75/88] target/riscv: rvv-1.0: trigger illegal instruction exception if frm is not valid Alistair Francis
2021-12-20  4:56 ` [PULL 76/88] target/riscv: gdb: support vector registers for rv64 & rv32 Alistair Francis
2021-12-20  4:56 ` [PULL 77/88] target/riscv: rvv-1.0: floating-point reciprocal square-root estimate instruction Alistair Francis
2021-12-20  4:56 ` [PULL 78/88] target/riscv: rvv-1.0: floating-point reciprocal " Alistair Francis
2021-12-20  4:56 ` [PULL 79/88] target/riscv: rvv-1.0: rename r2_zimm to r2_zimm11 Alistair Francis
2021-12-20  4:56 ` [PULL 80/88] target/riscv: rvv-1.0: add vsetivli instruction Alistair Francis
2021-12-20  4:56 ` [PULL 81/88] target/riscv: rvv-1.0: add evl parameter to vext_ldst_us() Alistair Francis
2021-12-20  4:56 ` [PULL 82/88] target/riscv: rvv-1.0: add vector unit-stride mask load/store insns Alistair Francis
2021-12-20  4:57 ` [PULL 83/88] target/riscv: rvv-1.0: rename vmandnot.mm and vmornot.mm to vmandn.mm and vmorn.mm Alistair Francis
2021-12-20  4:57 ` [PULL 84/88] target/riscv: rvv-1.0: update opivv_vadc_check() comment Alistair Francis
2021-12-20  4:57 ` [PULL 85/88] target/riscv: rvv-1.0: Add ELEN checks for widening and narrowing instructions Alistair Francis
2021-12-20  4:57 ` [PULL 86/88] riscv: Set 5.4 as minimum kernel version for riscv32 Alistair Francis via
2021-12-20  4:57 ` [PULL 87/88] target/riscv: Enable bitmanip Zb[abcs] instructions Alistair Francis
2021-12-20  4:57 ` Alistair Francis [this message]
2021-12-20 21:19 ` [PULL 00/88] riscv-to-apply queue Richard Henderson

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