hw/arm/boot: Make write_bootloader() public as arm_write_bootloader()

The arm boot.c code includes a utility function write_bootloader()
which assists in writing a boot-code fragment into guest memory,
including handling endianness and fixing it up with entry point
addresses and similar things.  This is useful not just for the boot.c
code but also in board model code, so rename it to
arm_write_bootloader() and make it globally visible.

Since we are making it public, make its API a little neater: move the
AddressSpace* argument to be next to the hwaddr argument, and allow
the fixupcontext array to be const, since we never modify it in this
function.

Cc: qemu-stable@nongnu.org
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230424152717.1333930-2-peter.maydell@linaro.org
[PMM: Split out from another patch by Cédric, added doc comment]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/include/hw/arm/boot.h b/include/hw/arm/boot.h
index f18cc30..80c492d 100644
--- a/include/hw/arm/boot.h
+++ b/include/hw/arm/boot.h
@@ -183,4 +183,53 @@ void arm_write_secure_board_setup_dummy_smc(ARMCPU *cpu,
                                             const struct arm_boot_info *info,
                                             hwaddr mvbar_addr);
 
+typedef enum {
+    FIXUP_NONE = 0,     /* do nothing */
+    FIXUP_TERMINATOR,   /* end of insns */
+    FIXUP_BOARDID,      /* overwrite with board ID number */
+    FIXUP_BOARD_SETUP,  /* overwrite with board specific setup code address */
+    FIXUP_ARGPTR_LO,    /* overwrite with pointer to kernel args */
+    FIXUP_ARGPTR_HI,    /* overwrite with pointer to kernel args (high half) */
+    FIXUP_ENTRYPOINT_LO, /* overwrite with kernel entry point */
+    FIXUP_ENTRYPOINT_HI, /* overwrite with kernel entry point (high half) */
+    FIXUP_GIC_CPU_IF,   /* overwrite with GIC CPU interface address */
+    FIXUP_BOOTREG,      /* overwrite with boot register address */
+    FIXUP_DSB,          /* overwrite with correct DSB insn for cpu */
+    FIXUP_MAX,
+} FixupType;
+
+typedef struct ARMInsnFixup {
+    uint32_t insn;
+    FixupType fixup;
+} ARMInsnFixup;
+
+/**
+ * arm_write_bootloader - write a bootloader to guest memory
+ * @name: name of the bootloader blob
+ * @as: AddressSpace to write the bootloader
+ * @addr: guest address to write it
+ * @insns: the blob to be loaded
+ * @fixupcontext: context to be used for any fixups in @insns
+ *
+ * Write a bootloader to guest memory at address @addr in the address
+ * space @as. @name is the name to use for the resulting ROM blob, so
+ * it should be unique in the system and reasonably identifiable for debugging.
+ *
+ * @insns must be an array of ARMInsnFixup structs, each of which has
+ * one 32-bit value to be written to the guest memory, and a fixup to be
+ * applied to the value. FIXUP_NONE (do nothing) is value 0, so effectively
+ * the fixup is optional when writing a struct initializer.
+ * The final entry in the array must be { 0, FIXUP_TERMINATOR }.
+ *
+ * All other supported fixup types have the semantics "ignore insn
+ * and instead use the value from the array element @fixupcontext[fixup]".
+ * The caller should therefore provide @fixupcontext as an array of
+ * size FIXUP_MAX whose elements have been initialized for at least
+ * the entries that @insns refers to.
+ */
+void arm_write_bootloader(const char *name,
+                          AddressSpace *as, hwaddr addr,
+                          const ARMInsnFixup *insns,
+                          const uint32_t *fixupcontext);
+
 #endif /* HW_ARM_BOOT_H */