Ronald G. Minnich (rminnich@gmail.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17254
-gerrit
commit 6b19021b75bc3cd48587c8805e9e5f6ed0c35299 Author: Ronald G. Minnich rminnich@gmail.com Date: Sun Nov 6 16:13:52 2016 -0800
riscv: change payload() to pass the config string pointer as arg0
The riscv 1.9 standard defines a textual config string to be passed to kernels and hypervisors. A pointer to this string is available at a platform-dependent location, default 0x100c on all extant platforms.
Define a new config variable, ARCH_CONFIGSTRING_RISCV, to contain this location and change payload() arguments so arg0 is this pointer and arg1 is the pointer to the payload.
Change-Id: I3be7f1712accf2d726704e4c970f22749d3c3f36 Signed-off-by: Ronald G. Minnich rminnich@gmail.com --- src/arch/riscv/Kconfig | 5 +++++ src/arch/riscv/boot.c | 6 ++++-- src/arch/riscv/payload.S | 4 +++- 3 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/src/arch/riscv/Kconfig b/src/arch/riscv/Kconfig index a30cb70..7c43da4 100644 --- a/src/arch/riscv/Kconfig +++ b/src/arch/riscv/Kconfig @@ -19,3 +19,8 @@ config ARCH_ROMSTAGE_RISCV config ARCH_RAMSTAGE_RISCV bool default n + +config ARCH_CONFIGSTRING_RISCV + hex "Location of pointer to RISCV config string" + default 0x100c + depends on ARCH_RISCV diff --git a/src/arch/riscv/boot.c b/src/arch/riscv/boot.c index ff1844e..f9cc54f 100644 --- a/src/arch/riscv/boot.c +++ b/src/arch/riscv/boot.c @@ -22,12 +22,14 @@ void arch_prog_run(struct prog *prog) { void (*doit)(void *) = prog_entry(prog); - void riscvpayload(void *); + void riscvpayload(void *configstring, void *payload); + char *configstring = *(char **)CONFIG_ARCH_CONFIGSTRING_RISCV;
if (ENV_RAMSTAGE && prog_type(prog) == PROG_PAYLOAD) { + printk(BIOS_SPEW, "Config string: '%s'\n", configstring); initVirtualMemory(); printk(BIOS_SPEW, "OK, let's go\n"); - riscvpayload(doit); + riscvpayload(configstring, doit); }
doit(prog_entry_arg(prog)); diff --git a/src/arch/riscv/payload.S b/src/arch/riscv/payload.S index 3261a80..e50a589 100644 --- a/src/arch/riscv/payload.S +++ b/src/arch/riscv/payload.S @@ -11,10 +11,12 @@ * GNU General Public License for more details. */
+// "return" to a payload pointed to by a1 with +// a pointer to the config string in a0. .global riscvpayload riscvpayload: /* Jump to a0 in S-mode */ - mv t0,a0 + mv t0,a1 csrw mepc, t0 csrr t0, mstatus li t1, ~(3<<11)