diff options
| -rw-r--r-- | config.h.in | 3 | ||||
| -rwxr-xr-x | configure | 15 | ||||
| -rw-r--r-- | configure.ac | 5 | ||||
| -rw-r--r-- | machine/mentry.S | 16 |
4 files changed, 38 insertions, 1 deletions
diff --git a/config.h.in b/config.h.in index dbacd78..98763ac 100644 --- a/config.h.in +++ b/config.h.in @@ -56,3 +56,6 @@ /* Define if subproject MCPPBS_SPROJ_NORM is enabled */ #undef UTIL_ENABLED + +/* Define if BSS should be manually zeroed when booting */ +#undef ZERO_BSS @@ -675,6 +675,7 @@ with_arch with_abi enable_print_device_tree with_mem_start +enable_zero_bss enable_optional_subprojects enable_vm enable_logo @@ -1314,6 +1315,7 @@ Optional Features: --enable-stow Enable stow-based install --enable-print-device-tree Print DTS when booting + --enable-zero-bss Manually zero out BSS when booting --enable-optional-subprojects Enable all optional subprojects --disable-vm Disable virtual memory @@ -4122,6 +4124,19 @@ else fi +# Check whether --enable-zero-bss was given. +if test "${enable_zero_bss+set}" = set; then : + enableval=$enable_zero_bss; +fi + +if test "x$enable_zero_bss" = "xyes"; then : + + +$as_echo "#define ZERO_BSS /**/" >>confdefs.h + + +fi + #------------------------------------------------------------------------- # MCPPBS subproject list #------------------------------------------------------------------------- diff --git a/configure.ac b/configure.ac index 1653f2b..81492de 100644 --- a/configure.ac +++ b/configure.ac @@ -107,6 +107,11 @@ AC_ARG_WITH([mem-start], AS_HELP_STRING([--with-mem-start], [Set physical memory AC_SUBST([MEM_START], [0x80000000], [Physical memory start address]) ]) +AC_ARG_ENABLE([zero-bss], AS_HELP_STRING([--enable-zero-bss], [Manually zero out BSS when booting])) +AS_IF([test "x$enable_zero_bss" = "xyes"], [ + AC_DEFINE([ZERO_BSS],,[Define if BSS should be manually zeroed when booting]) +]) + #------------------------------------------------------------------------- # MCPPBS subproject list #------------------------------------------------------------------------- diff --git a/machine/mentry.S b/machine/mentry.S index 84bd3c1..9ec9916 100644 --- a/machine/mentry.S +++ b/machine/mentry.S @@ -267,9 +267,23 @@ do_reset: slli a2, a3, RISCV_PGSHIFT add sp, sp, a2 + bnez a3, .LmultiHartInit + +#ifdef ZERO_BSS + # Zero out BSS; linker script provides alignment and padding + la t0, _fbss + la t1, _end + beq t0, t1, 2f +1:STORE zero, 0(t0) + addi t0, t0, REGBYTES + bne t0, t1, 1b +2: +#endif + # Boot on the first hart - beqz a3, init_first_hart + j init_first_hart +.LmultiHartInit: # set MSIE bit to receive IPI li a2, MIP_MSIP csrw mie, a2 |