diff options
| author | Leon Alrae <leon.alrae@imgtec.com> | 2015-06-19 11:08:43 +0100 |
|---|---|---|
| committer | Leon Alrae <leon.alrae@imgtec.com> | 2015-06-26 09:08:50 +0100 |
| commit | 3b3c1694cfd394b73de426edebdbf90c28f664fd (patch) | |
| tree | dcd93bdb3b5bc6a41bf4d9c518cca24925d10b94 /hw | |
| parent | ff334767728011218c62f7476232d260cb5b28e6 (diff) | |
target-mips: add Unified Hosting Interface (UHI) support
Add UHI semihosting support for MIPS. QEMU run with "-semihosting" option
will alter the behaviour of SDBBP 1 instruction -- UHI operation will be
called instead of generating a debug exception.
Also tweak Malta's pseudo-bootloader. On CPU reset the $4 register is set
to -1 if semihosting arguments are passed to indicate that the UHI
operations should be used to obtain input arguments.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/mips/mips_malta.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c index a5d64d5030..3082e75340 100644 --- a/hw/mips/mips_malta.c +++ b/hw/mips/mips_malta.c @@ -53,6 +53,7 @@ #include "qemu/error-report.h" #include "hw/empty_slot.h" #include "sysemu/kvm.h" +#include "exec/semihost.h" //#define DEBUG_BOARD_INIT @@ -634,7 +635,13 @@ static void write_bootloader (CPUMIPSState *env, uint8_t *base, /* Second part of the bootloader */ p = (uint32_t *) (base + 0x580); - stl_p(p++, 0x24040002); /* addiu a0, zero, 2 */ + + if (semihosting_get_argc()) { + /* Preserve a0 content as arguments have been passed */ + stl_p(p++, 0x00000000); /* nop */ + } else { + stl_p(p++, 0x24040002); /* addiu a0, zero, 2 */ + } stl_p(p++, 0x3c1d0000 | (((ENVP_ADDR - 64) >> 16) & 0xffff)); /* lui sp, high(ENVP_ADDR) */ stl_p(p++, 0x37bd0000 | ((ENVP_ADDR - 64) & 0xffff)); /* ori sp, sp, low(ENVP_ADDR) */ stl_p(p++, 0x3c050000 | ((ENVP_ADDR >> 16) & 0xffff)); /* lui a1, high(ENVP_ADDR) */ |