From: Martin Aberg <mab...@gaisler.com> Remember the initial stack pointer in start.S. It can later be used to determine top of RAM. --- bsps/riscv/shared/start/bspgetworkarea-fromstack.c | 55 ++++++++++++++++++++++ bsps/riscv/shared/start/start.S | 15 ++++++ 2 files changed, 70 insertions(+) create mode 100644 bsps/riscv/shared/start/bspgetworkarea-fromstack.c
diff --git a/bsps/riscv/shared/start/bspgetworkarea-fromstack.c b/bsps/riscv/shared/start/bspgetworkarea-fromstack.c new file mode 100644 index 0000000..b8a915e --- /dev/null +++ b/bsps/riscv/shared/start/bspgetworkarea-fromstack.c @@ -0,0 +1,55 @@ +/* + * This set of routines are the BSP specific initialization + * support routines. + * + * COPYRIGHT (c) 1989-2020. + * On-Line Applications Research Corporation (OAR), + * Cobham Gaisler AB. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#include <bsp.h> +#include <bsp/bootcard.h> + +#include <rtems/sysinit.h> + +/* + * These are provided by the linkcmds for ALL of the BSPs which use this file. + */ +extern char WorkAreaBase[]; +extern char RamEnd[]; + +/* Set by BSP early start code. */ +extern uintptr_t bsp_sp_at_entry; + +static Memory_Area _Memory_Areas[ 1 ]; + +static void bsp_memory_initialize( void ) +{ + char *end; + + /* top of RAM inidicated by initial stack pointer */ + end = (char *) bsp_sp_at_entry; + if (end == 0) { + /* fall back to linker symbol if not set */ + end = RamEnd; + } + _Memory_Initialize( &_Memory_Areas[ 0 ], WorkAreaBase, end ); +} + +RTEMS_SYSINIT_ITEM( + bsp_memory_initialize, + RTEMS_SYSINIT_MEMORY, + RTEMS_SYSINIT_ORDER_MIDDLE +); + +static const Memory_Information _Memory_Information = + MEMORY_INFORMATION_INITIALIZER( _Memory_Areas ); + +const Memory_Information *_Memory_Get( void ) +{ + return &_Memory_Information; +} diff --git a/bsps/riscv/shared/start/start.S b/bsps/riscv/shared/start/start.S index 04a62a2..0bb5ddb 100644 --- a/bsps/riscv/shared/start/start.S +++ b/bsps/riscv/shared/start/start.S @@ -59,6 +59,9 @@ SYM(_start): LADDR t0, _RISCV_Exception_handler csrw mtvec, t0 + /* Save stack pointer so it can mark end of work area later on */ + mv t3, sp + /* Load stack pointer and branch to secondary processor start if necessary */ #ifdef RTEMS_SMP LADDR sp, _ISR_Stack_area_begin @@ -74,6 +77,9 @@ SYM(_start): LADDR sp, _ISR_Stack_area_end #endif + LADDR t0, bsp_sp_at_entry + SREG t3, 0(t0) + #ifdef BSP_START_COPY_FDT_FROM_U_BOOT mv a0, a1 call bsp_fdt_copy @@ -145,3 +151,12 @@ SYM(_start): #endif #endif /* RTEMS_SMP */ + + .section .data, "aw" + .align 3 + + .globl bsp_sp_at_entry + .type bsp_sp_at_entry, @object + .size bsp_sp_at_entry, 8 +bsp_sp_at_entry: + .dword 0 -- 2.7.4 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
